ATauer
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41 minutes ago, Bill Kielb said:
Just so there is no misunderstanding a PID loop is a logic function or combination of components that create it. Controllers use PID logic, fuzzy logic or other logic. The ras pi uses some form of logic to emulate the PID loop function. The Bartlett control is a full control that stores multiple programs, can be up to three zones, has a program interface (keyboard and display) , relay outputs, fail safe programming, alarm output, etc… It is a complete control with built in PiD(s) that are already tuned for the typical kiln firing process. Since it is multi-zone, it also contains the equivalent of three PID control loops.
I mention because there seems to be confusion, as PID is a function, not a control and yes most temperature controllers contain PID logic and auto tune. It also seems you have all the necessary peripherals and parts to build a complete control. so for a couple hundred dollars, the Bartlett just might be suitable and an easy way to get multiple zones with weighted (helping) function vs three independent cheap temperature controllers.
In a pinch, any temperature controller capable of being programmed through a computer interface / keyboard could give you an equivalent way to store multiple schedules and easily load as needed through a computer interface.
Just mentioning, you might have everything you need whichever way you go. I still suggest you write out the design and anticipated sequence of operation.
I know just enough about PIDs to know about the loops, but your information was very helpful. I guess the misunderstanding was I was thinking with the Bartlett I would still have to do the programming and didn’t realize it came with so much. Having everything you mentioned-I don’t have three zones currently in my kiln but it is a big enough Skutt that I absolutely could go that way if I start noticing big differences between sections. The other things-especially the fail safe programming, which I worry about, although I do use the kiln sitter with a cone several cones higher than what I am firing to to make sure that if my electronic controller doesn’t turn off the kiln the kilnsitter will if the kiln starts heating up and might cause problems on another kiln, the multiple programs, alarms….since I absolutely can’t find any commercial kiln electronic controllers for anything under $800 + shipping $$$, paying ~$300 plus the ~$100 in parts I already have (not counting some parts I won’t need that I will be able to sell for a decent return) is a price I’m willing to pay to get rid of this headache and not have to stress about it any longer, and the side benefit of not having to brush up on my coding!
Thank you so much for taking the time to make it really clear what I would be buying and that I should easily be able to put the rest of what it needs together with what I have, and probably have a number of things left over to sell as well. I feel super confident in deciding to go for it, and I feel like 50 lb has been taken off my shoulders-thank you! Now to wait to Monday to make the call to make sure I know exactly what I’m getting at the place I plan to buy it and hopefully purchase it!!!! One of my big needs taken care of, finally! Now let’s see if you can pull a giant electric kiln out of your hat
I feel like the downside is we still haven’t identified the perfect RaspberryPi controller for the readers. I know I desperately wanted for many months of googling to just come upon something that mentioned it!
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12 hours ago, Hulk said:
Big, seems easier with gas.
Energy choice, local electric grid may be clean and low impact, or not.
Burning wood can be dirty- particulates, particularly - even with secondary combustion flame path design, which I don't see kilns having; I can see it being a choice, just not where I live now.
We heated with cordwood for decades, so. Now it's a switch, on the wall, forced air gas furnace.Copying files should be simple. The Pi uses a Linux variant, so cp command (copy), or mv (move).
Try the copy first.
Command line takes some getting used to. Just try a few commands a day, it won't take long to get the hang of it...I
The fast fire kiln design I would use uses very little wood, you can literally fire it with scrap wood, and it produces about less than 1% emissions of any kind. The ashes are reusable. Gas is never clean, they may be able to find ways to make it so not very many emissions are produced, but the process of obtaining and processing any of the gases used is extremely harmful environmentally, one of the dirtiest things humans do. I feel absolutely horrible using propane for raku but I have no other choice right now and I try hard to be as efficient and use as little as I can, so I at least don’t make it worse by using a lot. I took extreme care with building/designing my raku kiln to be as efficient and use as few BTUs per hour as possible, and then even added rigidizer and ITC-100 to make it even more efficient. Gas may be easier but it is not easier on my conscience. Fast fire kilns on the other hand can be decently sized, similar to the average gas kiln, about 20-30 cubic ft or so, but use a very small amount of wood which is a renewable resource in France where I would have this and if I’m lucky to get enough land I would grow bamboo to help fire it, which is extremely renewable and removes carbon while growing.
have experience using the command line, quite a bit of experience, but it has been several years and my computer is dying and I can’t afford to buy a new one right now, I will be getting by on my iPad Pro which is what I use all the time now. But you can’t program RaspberryPi from an iPad to my knowledge, you need the command line etc. If I was recommended a good program I might be able to use my mom’s laptop to do the coding. The coding is not the problem, I know it will come back to me if I watch a few youtube videos. It is having enough information about how to wire together everything and like I said above, even be told how the breadboard connects, there are no directions with any of the components and the RaspberryPi program I was originally going to use from github does not have enough information about building it, the electrical diagram is missing a bunch of key components and is very confusing, which is why I eventually gave up and started looking for a simpler PID I don’t need half the components for and have as simple interface sadly without the wifi and checking the kiln on my phone, but I can’t do any of that stuff with my other two kilns so a simpler PID that just ideally would save some segmented programs would be fine. I’m sure I’ll eventually find one like that, if I can find the right website that sells ones like that. Someone has to make them, these other ones are so damn close to just right.
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19 hours ago, Bill Kielb said:
Tuning properly can be extremely difficult. Auto tune helps a bunch but good PID loop process folks spend a lifetime becoming good at it.
If it’s several hundred dollars it is a control with faceplate, circuit board, built in relays, built in PID, etc…. If you intend to use SSR or mechanical relays you would use the output of the V6cf to drive them. You will need a box, transformer, fuse holder, cord, wiring, SSR’s heat sinks etc… regardless of which controller, even a Ras pi will require all the support stuff and probably more actually
A stand alone control will still need something to turn on and off which means relays, SSR’s box to hold them etc…. I am just saying, plan this out start to finish and I think you will have a better idea of how it all will work within your design. Right now there seems to be some confusion.
The Bartlett has a PID already tuned for the typical thermodynamics of a kiln and places to store programs. The RAs pi is all your tuning -100% and you need to write the entire program as well. Economical temp controllers have a PID and auto tune, else you are going to have to tune and they still require all the support: box, interconnect wire, relays, etc…..
I think if you define this completely an easiest path will become obvious.
Sorry, I wasn’t clear enough, when I said the tuning didn’t worry me it was because all the PIDs I was looking at had auto-tune and in the descriptions described how often it tunes itself and that the process is automatic. Otherwise I would be more concerned, but literally every single one had auto-tune, even the $16 ones! They mostly all seemed pretty great, with a lot of good features and most importantly with thermocouple input (K type for me) they measured -50C to 1300C as some other PIDs I was originally looking at, like the Inkbird ones, did not handle the appropriate temperatures. The problems is I’m still searching for one that will save segmented programs, which I hope is out there even if it is a bit more expensive. I’m just starting to figure out where to look for PIDs, I’m only on the one website AliExchange right now. eBay was a nightmare.
I already have all the parts for a complete PID, including the Raspberry Pi if I were to use that instead of buying one of the temp control PIDs. I have the metal box, the SSR, breadboards, heatsink, transistors, the thermocouple and its computer piece it plugs into etc. I would be all set if I could just find a better kiln controller program, or to use some of this stuff with a PID if I don’t go the RaspberryPi route.
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4 minutes ago, Bill Kielb said:
The Bartlett controls - touch screen and old V6cf are PID based, likely without the derivative portion and are reasonably priced as well as capable of storing multiple programs including many pre maid for glass. I think the price range for the controller board is 200.00 - 400.00 so maybe something to consider. Most temperature controllers are PID based and provide lots of segments for programming and can be had in the 50.00 - 150.00 dollar range. Problem is programming is a bit of reading and learning thing. Most folks do not know how to tune a PID process, yet auto tune is available on most.
I’m having an impossible time finding any PIDs so far that save multiple programs. There are some very reasonably priced that otherwise have great qualities, and they do segments- 32 segments! 50! But they don’t save them and they don’t have more than one it appears. The tuning doesn’t worry me, what I’ve read about it it sounds pretty easy. I just want to find one that will save multiple programs. Maybe there aren’t any, and I will have to settle for putting in my firing schedules manually every single time. I have looked at the Bartlett V6cf and the price is right at some places, but it is always very unclear if they are selling the actual controller, or just the faceplate. Because most places I have enquired including at Bartlett itself they say they only sell the interface, and I would have to pay someone to build a box and put the SSR and and some kind of PID I assume and all that stuff in it, and when they quoted me how much that costs, on top of the cost for the interface, it is basically as much as the Orton standalones which are already put together and ready to plug in, although nearing 1K these days, in the fall they were a lot cheaper. And it drives me nuts because I know these things they are selling for so much money are simple PIDs, they even say they are PID based, and I know I’m smart enough I could put one together with a little help, just some background in electrical work and brushing up on my coding. I hate the idea of paying over 1K for something I know I could make for under $200. But the frustration, and the amount of time it takes up, and how much it delays me being able to use that particular kiln are things I have to consider. If it was something I knew I couldn’t figure out it wouldn’t bother me so much, I’d just find the money somewhere, but the fact that I know I can make these….
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On 7/29/2020 at 5:20 PM, Jeryko said:
Hey Ollie. Just completed the build. Turned out better than expected. Only issue is that I did end up using more amps than I previously thought to get it to temperature fast enough. I'll write the specs if ur curious.
Thanks everyone else for the feedback and great ideas. Rpi controller rocks by the way :).
@Sorcery holly cow. Glad to see you here dude. Haven't had time for The Nut in quite a while.
The end product:
I know this thread is a couple years old by now, surprised it isn’t archived. I was super interested, thank you for providing so much detail as you went through the process. I got a “free” Skutt KS-1227-3, basically the second biggest kiln they make, except they seem to have not very long ago discontinued the KS line, but of course what I was told, by the woman who gave it to me who knew nothing about ceramics having never touched clay (super great Mother’s Day present from the Dad, ha! She scared the hell out of me so I can only imagine how this clearly clueless husband suffered after buying a broken down kiln at a school auction and gave it to her for her gift, men, sometimes!) was that it only needed new elements and a new cord to switch it make to its original 240 volts single phase so I could use it at home instead of the 3 phase 208 volts the school used and an obviously broken part of the kiln sitter. No big deal. Of course, after months of talking to the techs at Skutt, discovering with them each call some new thing that was missing, weird things, that make no sense someone would take them off, leading to me needing to rebuild the kiln sitter pretty much entirely as well as some heat switches using bolts so old that it took them weeks to find any in their warehouse. I’m in the process of trying to build my own electronic controller, for obvious reasons but also because I do a ton of glass casting and fusing, and you can’t use kiln sitters with that!
I tried really hard to do a Raspberry pi controller from the github creator Jbruce, but after having help from someone on Reddit about what equipment to buy, then not being able to find the new Raspberry pi anywhere for months until I finally found it online only in an expensive package with a bunch of accessories. But I’ve given up, JBruce’s kiln controller GitHub is way too confusing, his electrical diagram is wrong and is missing many things, his list of materials you will need only has about half of what you need on it, and despite watching tons of videos of putting together PIDs on youtube I cannot figure out how the damn breadboard fits into the work box I have, if I need the long breadbox part plus all the little ones that look exactly the same, because no one in the youtube videos used breadboards and the GitHub doesn’t explain anything about how they are attached/wired in, how many that came in that package of different sizes to use etc. I struggled through so many other things with that controller, and was going to do the damn programming of which he seems to have way more of than others I’ve looked at recently, even though I haven’t used python or any code since 2019 and I did bioinformatics for a while which is a lot lot different. Looking everywhere to try to figure out the breadboard thing just caused me to finally throw up my hands in defeat and decide to try and find a less advanced controller, initially thinking an Inkbird before finding out they don’t make them go high enough in temp, damn it. Now I’m on the AliExpress site someone on here mentioned which I’m super grateful for but the only problem is a lot of the PIDs sound good, and will have 32 or 50 step ramps, except it is very unclear with all of them whether there is just one program with all those segments or whether you can save multiple programs, which I would prefer, because not only do I have a couple different ceramic firing schedules but I have a bunch of different ones for glass, and it would be a pain in the butt to have to input them completely every time instead of having at least some of them saved, and if they can have 50 segments you’d think they could have more than one saved program. Seeing your post and your joy with your Raspberry pi controller is now making me rethink giving up, if you are still on here and can tell me which Raspberry Pi program you went with that was so successful maybe I’ll give it another shot. Although I would need to find out about the freaking breadboard.
I also was incredibly impressed you succeeded in making your own electric kiln, something I have been told over and over again is not possible. The thing is I make very large scale sculptures, and have to section them for firing and spend days epoxying them and hiding the seams after so no one can tell they were sectioned. I desperately want a huge electric kiln that I could fire my sculptures in one piece. But though I am saving up I won’t be able to afford one for years and years, they are usually well over $20,000. I know your small kiln is not anywhere near the scale I’m talking about, but seeing you accomplish it has given me hope. I also wanted to mention, for all the people who are carving grooves through bricks, that I have been seeing a ton of kilns on social media in New Zealand in particular but Australia and parts of Europe, with kilns with incredibly thick ceramic blanket as the walls with very thick coils of elements attached to the blanket. It is a very interesting kiln look, they have a lot less elements in there because they are so big, and I assume also because it seems that all the insulation is ceramic blanket that they are *extremely* well insulated. If I was to make any kind of electric kiln I think I would go that route after seeing these kilns, and hearing about how they can get to cone 10 at 1220C, which is what I use to get to cone 6 in my IFB insulated American made kilns! I’m a former scientist, although biology related, not something helpful for this like engineering, but it does mean I do have a little more background than the average ceramic artist in some tech stuff. The hardest part for me would be determining all the calculations for the elements, and then being able to get the gauge and even harder coil them to the right size. Otherwise I would just be making a huge ceramic fiber box possibly train style, and just need to hire someone to weld the steel for the outside. And by then hopefully I can afford a proper electronic controller or will have successfully built one hopefully. If I could build my own, I would be able to afford it so much earlier than buying one. That much ceramic fiber blanket will be expensive but a mere fraction of what a commercial one will cost. I just hope I can figure out the elements stuff, having no background in electronics or electricity. I’ve read a lot of kiln books & the chapters on electric kilns are always the same- do not actually write about anything about how they are made, except going into deep detail about the calculations for the elements, then end by saying that you really should never build one and just buy one. So unhelpful, whereas the chapters on all the other kilns are lengthy dissertations on all the ways and designs you can build yourself and how to fire them. In about 1.5 years my plan is to move to France, hopefully to a place where I will have room in my yard/property to build a big enough studio for the kind of work I do, or if I’m lucky have a nice barn or stable to set up in, and soon after I’d like to get that big kiln, and keeps my big but smaller electric kilns as well, and have room for raku and a large pitfire, and also space to eventually build a small fast fire wood kiln and a small soda kiln, under a shelter outside probably. The only way I’d have any ability after spending the money to buy a place & move there to get the big kiln any time soon would be to build it. ‘
And I know everyone will say to me the same thing they said to you, do gas, but I already feel horribly guilty enough using propane for raku, as someone completely against fracking, plus for my large scale sculptures I prefer a true oxidation firing usually, I don’t feel I could get what I want from a gas kiln. And for reduction that’s why I’m building the smaller fast fire wood kiln and soda kilns (also wood), which are much better for the environment than gas. I’ll still probably use propane for raku and feel horrible about it, but I’m not a fan personally of doing my raku electric or with wood, so I’m kind of stuck until they hurry up and invent something to replace it! And I am entertaining gas in a way, because if I can’t get my huge electric kiln built, I will be using Ian Gregory’s flat packed kiln- not the tiny one they show on his website but the huge ones I’ve seen in paperclay books where he is firing sculptures in situ using propane and different sizes and configurations of his flat packed kiln, which is essentially a raku kiln since it is made of panels of hardware cloth covered with ceramic blanket, and clipped together using metal clips like the ones for jumper cables. He consistently got to stoneware temps or all the way up to cone 10 in that, and it would be easy for me to make, cost a little less (and the ceramic fiber could be reused in a big kiln later on if I was able to start building it), and takes up no room in storage since it packs. Flat. There might be some overall advantages to just sticking with that long term, as it wouldn’t take up a bunch of studio space and instead of assistants and hoists and forklifts moving the sculptures to the kiln, I would move the kiln to the sculptures. The biggest downsides for me are that I’d be using a lot of propane with that, instead of electricity that I would also at somepoint be installing solar panels to offset, and I don’t think he got totally consistent temperatures with it always, it is exactly like raku. I’d also be struggling to keep it well oxygenated, although the thought of maybe occasionally doing one of my large pieces in reduction does have some appeal…mostly I just have one form in my head that is huge that would look fabulous in a blue celadon. But those can also be easily faked or I can do SiC celadons which tend to work out for me.
Sorry, I went too long. I learned a lot from this thread that I’m grateful for, like it is actually possible to build an electric kiln, even if very small. That I’m not alone in wanting to do that. And a few other tips and tricks…if you read this and can tell me or send me a DM with the github for the Raspberry pi controller you were very happy with I’d appreciate it. I’m super unhappy with the one I was trying to build and its hard to assess some of the others I’ve come across. Thanks!
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4 hours ago, Callie Beller Diesel said:
Dispex is what they use in the UK instead of Darvan.
I know that’s why I said it wasn’t available in the US. Some slips can be picky about their deflocculant and bone china is difficult in general which is why I was hoping it would do find with sodium silicate.
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11 hours ago, PeterH said:
Stumbled across this, which seems to confirm the point, and offer a mitigation of sorts:
to make it into a casting slip add 0.4% Dispex; to attempt a plastic body add 3% bentonite: I have used real bone ash and have not had the smell but I choose synthetic bone ash for it's chemical consistency batch to batch [my emphasis]
Oh funny, one of the recipes comes from the book Contemporary Porcelain by Peter Lane which I was *just* literally reading in the hospital, I finished it only a very short while ago. I hadn’t had the epiphany yet about stains and bone china, otherwise I would have written those down. Peter Lane’s book blew my mind, because almost every single porcelain recipe in it had a flocculant in it, Peter Lane said that every porcelain body benefits from flocculation, it supposedly makes it more plastic and increases green strength. And it came at a time where I was on the fence about using neph sye as my feldspar in my porcelain recipe, based on the literal rants Matt Katz would go on about using it or Minspar in claybodies in the CMW class, but having been seeing a lot of newer porcelain recipes with it, faced with the fact that the only potash feldspar I have access to right now is Custer, and I absolutely couldn’t bear the thought of going through the effort and pain of building a 6 ft sculpture and then having a big iron spot on it from the Custer. Also Tony Hansen has been extensively using neph sye in as many of Plainsman’s midfire bodies as he can as well as a bunch of opensource porcelain c6 casting slips he is working on- he emailed me and called it “The Feldspar of the Gods”. I’ll DM you what I ended up doing.
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1 hour ago, Mark C. said:
(I refuse to buy anything from Laguna)
(they said they might be able to order one or both of those kaolins with their quarterly chemical shipment from Laguna,)
Many companys buy from Laguna Clay
Well I guess thats not an option for you so on some other options
I use tri-calcium phosphate aka synthetic bone ash in a few glaze recipes and with great results-I burned thru a 50 # bag in about 5 years but not for slips-it works great for snappy glaze colors
I also use real bone ash from long ago as well-not sure if its still available .
also if you click on the posters name you can see when they last visited site Marcia Selsor has not been here since June 7 so not surprized she has not responded although you can turn on email notifcations that you receive an Email-not sure if hers is turned on-you could send it thru her website maybe
Well the last couple of posts provide me with a good amount of hope that synthetic should work, which matches what I know about the biology of it which I think in this case might even be more important than the chemistry of it. It is no problem at all to get as much of the synthetic as I want locally and for pretty cheap if I recall. I don’t even know where to get the real stuff as no suppliers I have looked at so far carry it. I have a surprisingly large number of glaze recipes where I use synthetic bone ash but using it in glazes versus using it in clays like most materials is completely different. I’m excited about the recipes (I have a number of recipes as well that I might try subbing in the synthetic, if I don’t love these first recipes) and hope sodium silicate will be fine as Dispex is not sold in the US. While it might not be as popular as a lot of other things for studio potters, at least having been very immersed in the porcelain world it seems to me like quite a lot of studio potters use it, but that may be two biases- following the careers of a lot of people in porcelain and the fact that many of them are in Europe, where bone china slip is sold by most of the big name suppliers. From what I have seen, it is decently popular there. Especially if an artists starts slipcasting porcelain it seems like pretty soon it is “well why not slipcast bone china?”. I know of a few major artists who throw on the wheel with it, I don’t know if I will pursue a plastic version, if so it would not be on the wheel (I’ve heard even there it has no plasticity) but handbuilding colored clay & I guess I’d see how much you could do with it. I doubt it would get anywhere near what I can build with regular porcelain that has been stained. That’s were I really wish we had Parian over here, because then I could slipcast in bone china and do handbuilt/sculptural colored clay work in Parian, which is so much more translucent than regular porcelain and of course has the self-glazing going for it/surface texture. It might be possible to mostly build sculptures with regular colored porcelain and add some plastic bone china as accents. It continues to boggle my mind how so many parts of the world just don’t have ceramic things that are so common in the other half of the world, including lots of lower middle income countries that often don’t have a lot of the basics.
***Continue reading only if you want a mostly detail-free reason for my feelings about Laguna and how and why I try to avoid them, having found out a few months ago about their huge wholesale monopoly inadvertently but doing what I can to avoid having to personally interact or give my money directly to them:
I had a horrible, extremely negative experience with one of Laguna’s clays that I won’t get into but the way the company handled it, their joke of customer service (*one* person who can deal with customer service issues for the whole gigantic LA company who won’t call you back for over 3 weeks, and won’t do the minimum to make things better that every other supplier would do), and their clay techs who make the clay knowing absolutely *nothing*, not even the most basics of basics, of the kind of clay I was using, means I do not want anything to do with their commercial products or to buy from them knowing the hell that would await me if I needed customer service, and a strong aversion to the idea of using their clay after having had horrible experiences with at least two very different clays. I have no control over who buys from their wholesale business and rarely know if a supplier buys from them (I would never have had any idea they had a wholesale business and one of my suppliers buys from them if they hadn’t mentioned it when I asked about ordering some different kaolins somehow) and most of those products are ones they are re-selling so it isn’t stuff they’ve made, I don’t have to deal with them as a company, and I can’t avoid them. C’est la vie, like most monopolies you might try and boycott they are everywhere, hidden, so you can’t really avoid them. I’ve accepted that but I can still avoid what I can control. I will be doing whatever is in my power to avoid their talc especially considering Matt Katz has tried it and says its awful. Sorry to go off topic but you seemed especially to be trying to say something about my refusal to buy from them.
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13 minutes ago, Babs said:
I read that you are in a very frustrating position in life.
So instead of slamming Simon Leach, let's focus on the positive.
What videos do you recommend?
Take care.
I’m not sure where you read anything about my life, but that has nothing whatsoever to do with my post about Simon Leach, which was clearly a gentle poke at the man in response to people saying he is just so utterly soothing and comfort food and it was clearly a joke. But it was also just a different experience with Simon Leach where he is very influential with some things, hundreds if not thousands of people have been influenced by him to convert their kilns into gas kilns, that is some serious ability to influence people. Hardly just the equivalent of a cup of soothing tea. I’m sorry that you could not recognize the joke, I in no way slammed Simon Leach or as you are implying are taking out anything from my personal life out on him! I have to say I feel a bit offended that you used whatever knowledge you have of my medical situation to let it influence how you perceived what I wrote, assumed that it influenced me with my writing in any way, and frankly if you know the severity of my medical situation saying something like “let’s focus on on the positive, what videos do you recommend” is rather offensive. It is not for you to tell me when I should feel positive or assume that I wasn’t completely feeling positive when I wrote that post, as if listing videos I recommend is going to fix my legs and my genes by thinking positive right then!. Maybe consider being a little more sensitive next time, don’t assume so much, and consider whether you should take out your sense of humor when reading a post.
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4 hours ago, Min said:
Why don't you make up some of that and give it a try?
I’ve been in the hospital almost two months and don’t know when I will be able to walk again and go home. I’m trying to do research and get answers so that when I get home I can just jump into a lot of stuff, including a ton of testing, and anything I can reduce having to just make some up as a trial, when if it doesn’t work I would then have to spend time finding someplace that actually sells real bone ash and order it and wait for the longer than normal shipping times to then do trials with that saves me time and effort and reduces by a lot the amount of testing I have to do. I have to do a lot of work when I get back to work doing extensive testing to get my white stoneware recipe developed, which will take up a lot of time, I have to do a huge amount of new glaze testing, and I have to do a large amount of testing of soluble salts, just off the top of my head. There is also the huge amount of testing I have to do with naked raku slips, glazes, and firing temperatures now that I think of it as well- and somewhere in all this I have to make a huge amount of work, as well as completely rebuild a kiln and finish creating the computer controller for it since I can’t afford to buy one. My to do list for the first month allowed to work is incredibly long, with the assumption that I make at least three 6 ft plus tall sculptures in addition to a bunch of smaller work- I have a month to create enough stock for my online store & that is going to be very hard. Any time I have that is not doing that is doing all these other things.
That is why I’ve been posting so much, hoping to get answers about naked raku and copper mattes, finding out if I need to find someplace that sells real bone ash and order it now so I’ll be ready, and so on, because definitive answers to any of the questions I have posted would make my post-hospitalization life so much smoother and faster and save mea ton of time, like if I had had my soluble salts questions answered (which Marcia Selsor never replied to the DM that I was told to send to her to ask her where she buys her soluble salts, and that is getting awfully close to a month since I sent the message without a reply) it would save me a great deal of time and even more money, so I’m just trying to make things easier on future me, unfortunately there just haven’t been many answers to the questions I have posed, perhaps they have been too specific for this kind of forum, but I don’t know where else to ask them, I haven’t found a soluble salts facebook group or anything! That is maybe an idea though, there is probably at least one bone china Facebook group and while I hate it when people who know nothing about an art form join a group and then say they are new to it and could you please answer this very basic question, or worse, explain to me everything you know about how to do this art form- obviously I won’t o that, I know lots about slipcasting and enough about firing bone china and so forth I can likely get started without any real help other than the question of the recipe!
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On 7/21/2022 at 11:28 AM, Callie Beller Diesel said:
I do have a colleague that did some work with bone China, and I think the difference is in bucket rheology. I didn’t have a really extensive conversation with her about it. While it might be technically chemically the same on paper, usually when you have a naturally derived material vs a synthetic one, sometimes there are practical differences. She did say it was a massive PITA to work with.
If you’re looking for translucence, you might also consider haloycite based porcelains instead. Polar Ice from Plainsman is one, and I’m sure there are others from US suppliers. You can get dry bags of them if you want to slip cast. They’re still primadonnas, but still more user friendly than bone China. They tend to be comparatively expensive because halloycite kaolins come from Australia mostly, but they’re very beautiful.
Continental Clay had never heard of Halloysite or Super Standard for that matter when I brought up to them if it would be possible to order better quality kaolins other than just Grolleg as a special order! MN Clay Co about 20 minutes in the other direction (I guess a long time ago they were one company but split up, which is interesting because they are both family run so I’d love to learn about what must have been a lot of drama to have a family split apart into two ceramic suppliers in one city, when many people don’t have a supplier anywhere near them!) either had heard of them or just pretended to when I asked and months ago they said they might be able to order one or both of those kaolins with their quarterly chemical shipment from Laguna, and I guess mark up a price for me, but we’ve since had some huge back and forths about how 90% or more of their stonewares and all of their porcelains, even the cone 10 ones, don’t come anywhere near vitrification, which they don’t think is a problem, and they also lied to me telling me the porcelain I panic bought a lot from them because at the time it had been months since anyone had been able to get Grolleg delivered to Minnesota, this porcelain had been out of stock for months, and I was afraid with the Grolleg stuff it might go out of stock again really soon and it was the *only* porcelain in Minnesota that I could potentially handbuild and sculpt with, so they lied and told me it was vitrified at cone 6 (try over 4% absorption!) and that it was translucent, a big requirement for me, but then I learned they put ZERO feldspar in the porcelain which means it literally can’t become translucent. They told me if I wanted several clays I’d bought from them to be vitrified I should buy a bunch of feldspar from them and find out how much I would need to add to get it vitrified at cone 6, and seemed shocked when I told them if I did that, which I shouldn’t have to pay for a bunch of feldspar that should already be in the damn clays, especially the porcelain, that I would also need to use frit to get it actually down to 0.5 % or less at cone 6, because clearly they have no idea how to make clay. So we’ve been arguing about it for months, because they have a no pugged clay return policy, which should be waived when they purposely mislead me about a bunch of things, and tried to tell me it didn’t matter because no one makes functional ware out of porcelain anyway!!! I mean, they own a clay company, they should know vast numbers of functional potters use porcelain and I need mine vitirified and translucent for my sculpting for a variety of reasons. So we are not on good terms and I don’t think they would order Halloysite for me.
I have looked long and hard for Halloysite to buy to use as my kaolin in my homemade porcelain recipe (the only way I could have a porcelain that actually does everything I need it to do without paying tons of shipping - and I haven’t found a porcelain I’m happy with for sculpting at any places in the US.) To buy Halloysite it has 1) doubled in price from where it was a year ago because of shipping/supply issues and 2) the shipping costs for a 50 lb bag are 4 times what the expensive bag costs, so I super can’t afford it especially as I would be going through at least one 50 lb bag a month if not more often. It also isn’t really what I’m looking for with the bone china, or if I could get Parian in the US I would also love to use that with my colored clay. The bone china would provide way more translucency and a hard glass like final product that NZ Kaolin clays just don’t have at all to the same degree, if I could get it. It is really basically glass. My ideas for using it with color are very specific and an actual porcelain just would not work - otherwise I would just stick with my porcelain recipe I developed coloring it, which I do, and works great, and I would keep doing things with it, I just couldn’t do what I could do with bone china.
I get your comment about the chemical content of things maybe being the same from different sources but having different properties, but what is in bones is very simple and as a veterinarian I would say that there is nothing special about bones that provides anything different as far as I can see other than what is in the synthetic, it is not a complicated material. Which is why I really think it should work just fine but all these old porcelain books say you need the real thing for bone china versus using it in glazes, but they are pretty out of date so I’d really like to find something modern that tells me one way or another. If I could use synthetic and make my own slip, it would be pretty darn cheap with such few ingredients and so little Grolleg. I’m looking for some very specific ways of using colored clay with bone china, that as I said no real porcelain no matter how white would work. 1.5 years and I’m living in France and will have all these things at my disposal and I will also get to use Parian for colored clay too which will be amazing, but I’d hate to have to wait that long to use bone china. There really should be a pretty simple place to find out if synthetic is good enough or not, so I don’t understand why I can’t find something like that. I could make a test batch I guess with the synthetic and see how it turns out. I wouldn’t be throwing it or anything so I shouldn’t have the problems your friend had, it would mostly be casted with a small amount of handbuilding, I make Egyptian paste and sculpt it which is supposed to be even less plastic than bone china so I think I could handle it.
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On 3/21/2020 at 7:38 PM, liambesaw said:
Simon is more comfort food than learning experience, I'll give you that. He's a comforting figure you can tune into for some soul time. He has about 100 videos on making tankards but his British charm and soothing voice are something that I tune into just for fun.
Well, I don’t know, I watched one episode of his and suddenly was going to convert the large Skutt KS-1227-3 I had gotten for free but needed about $600 worth of work and I’m still *@#$@% working on making my own PID computer controller for it, but the next thing I knew, having already gotten all the parts I needed from Skutt and Euclid’s for the new elements I was going to return everything and turn my kiln into a downdraft gas conversion! One freaking episode! I became obsessed and tried to find any information I could, the downside was I wouldn’t be able to use it for glass but my other kiln would be able to do that, and while my huge oval Olympus was annealing glass for 6 weeks or just full of oxidation fired ceramics, I would have a gas kiln I could technically fire in either reduction or oxidation if the Olympus was not available and I needed to fire some clays I have that are oxidation only. I was overjoyed! Days of work fixing it up gone, replaced by a day of putting a downdraft chimney in it which seemed simple enough, he uses a weed burner instead of Venturi burners so that would be cheap, I wouldn’t have to figure out that damn computer part, and best of all I had a chance to actually fire to cone 10 if I wanted since all of my kilns only go to cone 8 or even lower, and I could spend endless hours perfecting copper reds, getting beautiful celadon and Juns, and ….actually those are pretty much the only reduction glazes I’m really into, although I am obsessed with them if that makes up for a lack of interest in all other reduction glazes.
Thankfully my mentor reminded me I would have to babysit for 9 hours every firing in my freezing garage in Minnesota, when I could be making work instead. That having never been taught how to fire gas kilns (other than Simon’s other videos!) it would be a steep, very long curve being able to get anywhere near cone 10 and managing to get reduction right at all. She estimated it would take me about a year of firing on my own before I would be able to consistently produce ware looking anything like I intended it to. That I wouldn’t get to use the Skutt also for some glass casting and fusing if it was gas. The thing that finally convinced me there was no way I should do this was misreading Ward Burner’s technical pages where he listed what size propane tanks you would need for different sized kilns, and thought for my size kiln I would need a 250 gallon tank but really I would regret it if I didn’t get a 500 gallon tank which, haha, I was not going to get a permit for in Minneapolis and my family was in no way going to let me put a tank that big in the back yard. In actuality I think you need like two 100 lb tanks which is totally doable in Minneapolis because I’m now doing one to start with for my raku kiln, they come out and exchange my tank with a full one once mine is empty and I don’t have to try and move it or anything. So I’m saying Simon Leach is not all British soothing comfort food, he can also be extremely dangerous and just so plausible and convincing.
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I’m considering doing a little work in bone china, an escalation of my strata casting with paperclay porcelain so I could have works that still have layers of color but are much more translucent then the porcelain I use for strata casting right now. I would also be interested in building on Angela Mellor’s work with bone china and paperclay, since paperclay is the only reason I’m in ceramics, and I feel that inspired by her work there is lot more to explore with the two together.
But the suppliers near me only have synthetic bone ash, and I’ve always heard for actual bone china you need the real thing. Which I’m rather hoping isn’t true. As a veterinarian of many years and a former vegetarian, while I realize those bones would just have been used in other ways or disposed of, I just can’t help feeling really really uncomfortable with the idea that my artistic medium is half made of dead animal products. I don’t judge anyone who does, see what I just said about the bones otherwise being either wasted or used for something else, but it just makes me personally uncomfortable. I can also imagine all the people in my life who gave me constant crap for becoming a vegetarian at age 11, and then crap when I was forced by my doctor to start eating meat in my 20s, giving me hell for using bones in my work.
I haven’t been able to find really any information about why real bones are supposed to be used for bone china, I haven’t found anything scientific that explains it. And it seems to me that the synthetic is literally the exact same substance, just sourced from different things, so the chemistry shouldn’t be any different and it seems to me like synthetic bone ash should work for the clay (well, I rather consider it much like Egyptian paste, more of a glass like material with things in common with clay, which I love because nothing makes me happier than working with material I feel joins my two main mediums of glass and clay).
Thanks for any clarification or pointing me in the direction of anything that breaks it down. I’m just going off of books on porcelain, some of which are not very recent, just flatly stating it without providing any actual reason. So something that provides context would be very helpful!
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3 hours ago, Babs said:
Another thought is you run a dry straggly brush loaded with wax lightly across the top of your saucer, thus screening the high bits from the wash when you then apply the underglaze, or stain to your piece. The high points, well most, would be coated with wax resist, the wash would be taken up by the low bits only???
Maybe, i e like dry on dry watercolour technique, or masking with a stiff sparse brush...
I will keep this in mind for the other two saucers if the sintering doesn’t work. Brushes are my weakness for tools, I am constantly buying new ones and new sets, even though I’ve barely used the set I just got before! And with me starting a specific body of work very different than the rest of my work, where I want to do majolica on cone 6 black stoneware (leaving parts of the clay uncovered or carved so that it is obvious I am not using terra cotta) I’ve become obsessed with buying lots of calligraphy brushes, having found out they are really the best for doing that kind if painting, and that they hold a lot of paint/glaze so you don’t run out when making a long line…so I don’t have much in the way of old stiff scraggly brushes- probably one or two old wide wall paint brushes in the basement, otherwise I had gotten rid of any brushes I couldn’t recondition so I could buy more, good quality brushes for pretty much every possibility…except this apparently! I do have quite a few of the extremely inexpensive chip brushes from the hardware store in different sizes that I had bought for applying silicone to models for molds (since I am also a glass caster and usually make a master mold, and sometimes I make master molds for models for my plaster molds, but I tend to just have around 5 or so plaster casting molds going at any one time, for strata casting, so each casting has unique layers and colors of porcelain and the carvings revealing those colors are always unique, and to keep things fresh when I get bored with a casting type I just throw the mold away and make some new ones, with the idea that these are all limited edition unique castings, so a master mold in that situation is usually a waste of time and expensive silicone!).
The chip brushes are pretty stiff and with some extra bending and beating up by me might work. I could potentially try it out on a smaller piece, bigger than a test tile but not one of the actual saucers, with the same texture, to see how that works. My sense is that there would probably be a good amount of the high points that wouldn’t get wax on them and would be black, and that the wax would also seep into the valleys preventing the black from getting in there. This had actually been one of my first ideas for a way to try and avoid 3 firings, but I just didn’t think it would work. I had also considered doing sort of the opposite, using one of my thin liner brushes and carefully putting wax on each ridge, but that would be so incredibly time consuming I rejected it. When it comes to painting or Sgraffito I can really get into a lot of detail work, but I think this is one of those things where it would just be too much!
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On 7/2/2022 at 8:51 PM, Babs said:
Right so a visible saucer does need the attention you are giving it.
Your glaze is very opaque and does not move?
Your glazed pot could be sintered, then stain aplied and wiped. If glazr is very opaque, underglazing won't work, you'll ned an onglaze technique.
Could try adding low temp frit to the onglaze stain to add to its flow and melt and thus it will pool
Sintering it is a really great idea, I think I will try that out. I’ve mentioned a few times that I make my mason stains 1:2 with FF 3124 and water, I don’t ever use mason stains with just water, so it should be plenty sticky and have a bit of flow and even gloss, since 3124 at temps like 06 is in fact a complete glaze within itself. I try and avoid using Gillespie borate (don’t have access to Gerstley locally anymore) with the stains if I can because I find it gels up the mixture more than I usually want for what I’m doing, but it is also an option especially for people who are having trouble getting frits right now.
I really like this idea- I’ll have the two others glazed in case for some reason this doesn’t work. I need to start thinking of some creative ideas of what to do with the hopefully superfluous extras I’m making, if I have one or two left over that are perfectly good I feel like I would need to make some planters for myself that would fit these saucers, or, since the rest of my work in made in paperclay, and you can add wet paperclay to glazed clay, even if it isn’t paperclay, I could use these or carefully broken parts of them added to a paperclay sculpture, wallhanging…something. I really really hate wasting clay and while I marvel at the really cool chemistry that is vitrification (or I guess actually sintering at lowfire temps) I wish there was some way to have your clay turn ceramic permanently but also have something you could dip it in or spray it on that reverses the process and the clay could be recycled and used for something useful. But probably the simplest thing if I ::knock on wood:: have extras would be to make some planters for myself that match, I’m positive my mom would have plenty of plants that could go in them.
Thank you so much for the sintering idea! I don’t know why I don’t think of sintering things more often, there are a lot of good reasons to do so!
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18 hours ago, Callie Beller Diesel said:
I’m a bit behind on my forum reading, so I’m only getting to this now.
This example is the exact reason why I don’t offer glaze choices outside my existing glaze stable to commission clients. But at this point for you, that’s a future consideration, and you have made a promise and you need to deliver. So. Onwards.
As much as we all hate being told we need to test things, in ceramics you can’t get away from it. You’re probably not getting this saucer out of the kiln in anything less than 3 firings, but what goes into those kiln loads in what order is what’s up for debate. My suggestion is to do the tests before taking on the piece itself, but you’ll have to decide if the ADHD squirrel will let you do that or not. If you charge ahead without testing, you’re going to wind up doing as many as 6 to try and fix the screw ups.
You need a darker-than-the-version-you-used glaze. Have you first tested to see if a thicker application of this glaze does what you’re describing, or is it an opaque one that doesn’t change much? Is it really flat, or is there some reactivity to it?
There’s actually nothing saying you can’t add stain to an existing commercial glaze to alter the colour, although you’ll have to do some testing to figure out if a stain or an oxide will work better to modify it. You may void any claims about it being food durable, but that isn’t a concern in this instance. You’d want to make some line blends to find the right tint you want, but this could solve the problem. As long as the specific gravity of your glaze remains constant, you can add dry ingredients to x number of grams of the wet glaze, sieve thoroughly (2x through an 80 mesh test sieve), and get repeatable results.
I think the best way to do a wash that gets wiped off of the high points on a texture would be to either try it underneath, especially if the glaze is in any way translucent.
If it’s opaque, you’ll to bisque, apply glaze, bisque again, apply and wipe the wash, and then fire a third time like I think you have been wanting to avoid. Sorry!
There’s nothing wrong with firing a kiln partially full, even if it’s more efficient to have other things in it. It’s not stupid if it works, and you’d be surprised at how much firing an electric kiln doesn’t cost. Here’s a link to an archived thread describing how to calculate yours.
That said, filling the blank spaces with test tiles is a most excellent plan. You will pretty much never be sad to have glaze tests as references, whether you think they worked at the time or not. The information you gain from them will help build your skill and knowledge base, which is incredibly important for anyone working with commissions or doing bespoke work. You need to be able to guide your clients through what’s possible and what isn’t, and you can’t do that effectively if you don’t know yourself. When I was working at the glass place I spoke about in the QOTW thread, we would make random stuff just to see if it worked or not, and they then got used as showroom samples. If there was space available in the kiln, we always put something weird in, or tried to ‘break’ something to see how hard we could push a material.
You may have missed the parts where I have said that the glaze is extremely opaque, that I even put on two washes under the glaze on the actual moon jar and not a damn thing showed through at all. I also slapped my forehead because I wasn’t thinking at all when I said I could fill the kiln up with test tiles, since I fire at cone 6 I really don’t have any cone 06 glazes that needed to be tested and while I will have likely some of the earthenware clay left over not enough to make a ton of test tiles, and I don’t want to waste my dwindling supply of good raku clay I love on test tiles for glazes I won’t use. I figure I will probably make a few mugs (the exception to my absolutely no mugs rule is for myself, and most of our hodgepodge of commercial mugs have broken so I could use a few more for using for me tea- ones that won’t be allowed to be used for the cat’s water, since all 4 cats refuse to drink out of bowls or even fountains they will only drink out of cups and mugs, because they think they are drinking out of what we are drinking out of, weirdos).
I know that each individual kiln firing is not a huge huge amount of electricity, but I am trying to save on that as much as I can, the kiln I’ll be using is absolutely huge unfortunately. As for the glaze, no more layers does not make it darker. I really don’t see how I would end up with doing it 6 times if I don’t test it, I am doing something I have done a hundred times, brushing on stain with some frit to emphasize the texture and wiping off the high points, I could do it in my sleep, and while very close up you’ll be able to see it from farther away it will just look darker. I’m only doing the other two saucers not because I’m worried about the stain but because of anything else that could go wrong that would make me happy to have a couple extras- a crack, a chip, etc.
As a sculptor I have an extremely large number of glazes I work with, I don’t have a large enough studio to have very many in buckets as there just isn’t space for that, so only a chosen few get to be in buckets. Most of the others I have already made up are kept in quart sized yogurt containers or gallon sized old kitty litter containers. These are for my medium to small scale work and tile and wall panels, with quart and pint containers housing my many different colored slips (which I use a lot, I love love love slip), homemade underglazes, and colored terra sig. For the majority of my work which is large scale- as 5-6 ft or even more, I mix up the glazes I want to use on the sculpture in the amount I need, and save any left over in the smaller containers. Because I can very easily do things with glazes, and don’t have a set palette like a lot of people because that would just not work with how I work, I have no problems making up new or different glazes for commissions or custom work. Remember as a sculptor who only rarely makes utilitarian work, commissions and custom work for me are usually quite different than requests from a customer to make a mug in a certain color or something. I assume that for a lot of commissions and public art that I will have to even develop new glazes in order to make work that is satisfactory. I have no problem with that, especially since contracts are my best friend, where I get to lay out that I will do my best to achieve certain colors if those are requested, but due to the nature of glaze making that I may not be able to achieve the exact color requested, but will try to get as close as is possible.
Really, I think a lot of advice for custom work for potters doesn’t translate over to sculptors very well. Our commissioned and custom work is very different, often architectural or public art, where contracts spell things out very well and protect the artist from pretty much all of the situations that seem to bug potters. For fun and relaxation I do make a tiny amount of functional work, just because I like the forms, or for vases I can make them very sculptural, and I can also for some things use glazes that I would rarely get to use on sculptures but really like, like floating blue for example. But each piece is a one off and not repeated, except for the occasional sets of stemless wineglasses I make, but each set is unique and will never be sold with that glaze combo again. Because it is important to me that any of those things are unique, I won’t take custom requests on those. This situation is unique for me because I would only do this for this specific friend, just like I am willing to make a set of custom mugs for him but would never do that for anyone else…unless they are handing me a suitcase with a million dollars in it. I do the functional work because it is fun and often creates canvases that I can go crazy with surface decoration, lots of slips and underglazes and seemingly clashing designs but as one of my mentors says I’m like a jazz musician who can take the disparate melodies and make them work together to create something that she says is a Tour de Force piece. Or having the chance to do intricate Sgraffito, that and carving are quite literally my favorite things to do in sculpting, but when I’m making 6 ft tall sculptures I have a lot less opportunity to do Sgraffito and while I can do some carving not usually very intricate carving with a lot of piercing and so forth…the pieces are just too big and it would take too long to do those things, although I do try and do some of it, but they tend to me long lines that cover large spaces instead of what you can do with Sgraffito on a cup, a plate, a platter etc.
But back to my original point, I love glazes and have so many different colors I want to use, more than I get the chance to, plus add in my wide palette of colored slips, terra sigs, and underglazes- since I make them myself with mason stains using Vince Pitelka’s recipe(s) from Glazy, I have way more options than those using commercial underglazes, and for 1/5 the price, if I was a functional potter I would be very unlikely to have an actual “glaze stable” as for fun I am always trying new glazes, using SiC on reduction glazes, doing line blends and triaxial and quadraxial blends to adjust a glaze or try and find a new one, so I would likely jump at the chance to do some custom work with a different color/glaze, if it is a color I like- I’d probably say no to yellows or oranges. But I would have a short contract spelling out the possible limitations and what the client’s backup choice is for a glaze, and depending on how much work I would have to do charge accordingly for the time spent on the glaze.
But I look at someone like Joe Thompson, who has invented a crazy number of glazes in the last few years, and always very generously shares them on Glazy and his blog for everyone to use, he loves the process of developing new glazes and has a real knack for it, and he then gets to offer more of his limited amount of functional pieces he offers in these colors, so I could see someone like that enjoying the challenge of trying to develop a new glaze for a client who wants something specific knowing that if I would succeed in making the glaze, or close enough to it, I would increase my money making opportunities, but again have boundaries with the client that they are paying extra for the glaze research time and testing and that if I am not successful they either need to have a backup glaze they are happy with or a quit fee for the project if they would rather not have anything at all. Part-time for a few years towards the end of my scientific career I did some scientific/medical writing, and I learned a lot about contracts and how important it is to build very detailed requirements on the clients part and what they want very clearly spelled out, with all my limitations spelled out if some things can’t be delivered on, but being paid appropriately for the amount of work especially if there is more work than is typical for a project, charging a project fee, having that fee paid in three installments, 1/3 up front, 1/3 at a certain point of deliverables, and 1/3 on final delivery of the product. And to have a kill fee in it if the client wants to terminate the project that I get paid for however much work I’ve already put into it including calculating in that while I was working on that I could have been working on something that would have gone to completion and paid me more since that would have been finished and I would have gotten the entire payment. Ceramic artists need to be embracing this model and get paid partly upfront, especially if it requires you to get any materials you don’t normally have on hand, at some kind of middle point, and then on final delivery of the product. And if custom work requires extra effort on your part of any kind, whether that is using a glaze you don’t usually use so you have to do some test tiles, a test bowl, and then possibly the BWIC, microwave, cutlery etc tests if you need to determine its durability and whether it can be used on food surfaces, then that should be factored into the price. I can’t think of any other industry or artistic practice where it isn’t already assumed on the part of the client that asking for custom work means you are going to be paying more. I have an addiction to gorgeous Indigenous made earrings I developed during the Pandemic as a weird way of coping with the Pandemic stress, and if I ask for something custom, colors or something, I assume I will be paying more. Sometimes I don’t, especially if I ask to buy a set of earrings that has already been bought and the artist offers to make a custom set similar in design to those earrings but lets me pick colors or length or width more, they may sometimes just charge what that original set of earrings cost, but I never assume that will be the case. If you want to talk to me at the next NCECA look for the white woman with either black or turquoise hair who is wearing every day beautiful, often very long, Native earrings…
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25 minutes ago, Bill Kielb said:
Pretty much use your standard techniques for highlighting and shading, I never wiped my airbrush art. Color mix can make things easier, mask techniques fairly common as well. It definitely takes practice and getting used to spraying underglaze but pretty easy to infill reliefs, wash, blend and highlight free hand.
Regular air brushing techniques are fine and depth is something that can be achieved. For newbies I used to start folks out with spraying using simple masks and several shades to build their skills and confidence.
Quite common to use stains as a colorant in many glazes BTW, It might prove an easy (fairly inert) way to change the tone. To fill in low spots you may prefer underglaze to that of stain just because it will stay on the pot better than straight stain.
I’m moving away from using any commercial products, so while I still have some underglaze to finish up using, I make my own underglaze now from a recipe on glazy that comes from ‘70s Mason stain company via Vince Pitelka, it has three separate parts that are mixed together, and with the liquid underglaze brushing formula he developed (a mix of propylene glycol and CMC and water) for painting it is quite quite thick, like slow moving lava, but brushes on like a dream and is especially great for majolica. Plus it costs about 1/4 or 1/5 the cost of commercial underglaze, and you have basically an infinite palette from the stains, especially since if you vary the amount of stain you put in you get different colors, and they blend really great plus at least the Mason stain company has a ridiculous number of colors. And the CMC and propylene glycol help it stay on the pot really well. I haven’t tried airbrushing those yet, certainly they can be thinned with water I just don’t know if for some colors they would be thinned so much to fit through the nozzle that they wouldn’t provide enough coverage. But I imagine that is also an issue with regular underglazes…of which this recipe is really very close to how they make commercial underglazes, the dry part has frit and kaolin which is a big part of underglazes plus a lot of stain and CMC, and that is really what most underglazes are made of. The difference with Vince’s version is really the propylene glycol, which really makes a difference in having it paint on like butter, but is a lot thicker than how commercial underglazes are formulated. I guess I’ll just have to play around with it and see what colors work thinned out and which ones don’t, or if they need additional stain added to the thinned mixture….But I couldn’t be happier having this recipe for underglazes, saves me so much money, works super well, and most colors work at any cone without the changes in color you tend to see with other underglazes when used at different cones.
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12 hours ago, Bill Kielb said:
I do know my fair share of sculptors, painters, potters that begin to despise commissions when they don’t meet expectations which often infringes on the artists creativity or for painters, make me look 20 years younger than that special anniversary blurry picture taken of me. So I think it can happen quite often as a career matures. I think likely similar to your hard and fast rule about not making mugs. For your reasons they don’t excite you. Next to Last thought, maybe a mix of glaze from the same manufacture in the same family so to speak gets you closer to the tonality you desire. Since it’s fully opaque, maybe thin with clear and then change the undertone of the clay. Think creatively and test. There is no guarantee the glazes will work together and no guarantee about durability but I think it has a fair chance of getting you closer.
wiping underglaze off freshly applied glaze
I would agree - wiping underglaze applied over freshly applied glaze seems challenging at best and tough to repeat, still you may find a way to do it. Please share your success, everyone seems to be trying to find a potential solution for you it would be nice to add another tool in the bag of tricks.Last thought, I have airbrushed underglaze so if you are familiar, it can provide a way to highlight and shadow / shade an in-glaze solution without wiping.
I do airbrush, more and more actually, so I would very much be interested, just for future projects, how you highlight and shadow without wiping!
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12 hours ago, Babs said:
Perhaps photos will help solve ,help this.
Just how much of the saucer will be visible?
A pedestal style may take less away from the moonjar.
Low fired saucer will weep onto whatever surface it is placed on. Avoid the Frenchpolished Grand piano.
I’m in the hospital so I don’t have photos. And I really don’t see how photos would help, I’m not asking for suggestions on how to design the saucer, just trying to see if there were any ways I hadn’t thought of to avoid firing it three times. It will be completely glazed all over, so it should not weep onto anything, but he does know not to keep it on anything precious or if so to put a mat under it, like you would for terra cotta (which is also lowfired and I have many many commercial terra cotta pots with plants in the house and they do not weep ever. The only concern is potentially overfilling when watering and having the saucer spill over. I’m really not concerned that the saucer is going to take away from the Moon Jar. I will take some photos of it as just a Moon Jar for my portfolio before I send it off, and the way I’m picturing it in my head looks really nice- less recognizable as a Moon Jar but a very nice round planter with very interesting texture and a beautiful glaze even if it is commercial, with a low wide saucer that I think provides a nice accent for it, considering that very few people who are going to see his planter are going to be like “Hey, that was clearly a moon jar and now it looks like less of one because of the saucer!”. I think we sometimes forget that most people don’t know what any of those kinds of things are unless they are collectors. The saucer will be very visible, he wants it that way, and considering that it was my first moon jar I didn’t put as pronounced of a foot as I could have, plus some of that foot got broken in the kiln, hence it turning into a planter, so as it is just looking at it plain you don’t see a ton of foot as it is. In this situation a pedestal type style really wouldn’t work with it but I will keep that in mind should this ever happen to me again! I raku moon jars, which are not supposed to be functional but some people do want to use them as vases or planters, and I simply tell them it is not waterproof (although is very well waxed) but at least for planters you actually want some absorption and porosity, so someone may some day want a raku saucer to go with their raku moon jar and I will keep the pedestal idea in mind as an option.
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On 7/1/2022 at 5:24 AM, PeterH said:
Would adding an "inert" stain to the commercial glaze serve your purpose?
I suspect stains consisting of spinel pigments would be suitably inert, although obviously check the small-print.
For example Mason 6600 best black 6600 https://www.masoncolor.com/ceramic-stains/blacks/6600-best-black).
reference notes https://www.masoncolor.com/reference-guide
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Don't know how serious the advice "Use only as a body stain" is. For example
https://www.scarva.com/en/gb/Mason-Stains-By-Mason-Color-6600-Best-Black-Stain/m-2170.aspx
Our range of Mason colours with over 60 ceramic stains can be used in a wide variety of cost-effective applications. All stains in this revolutionary new colour system contain NO LEAD and can be used as glaze stains ...
The thing about only using as a body stain is something you can just ignore. I use stains a lot, hence planning on using the black stain to fill in the low texture and make the whole thing look darker, but I could definitely take a small portion of glaze and mix some black stain into it and see if it darkens it. No harm in that and I would learn something useful whether or not it works. I have never heard of anyone darkening a commercial glaze with stains, but with studio glaze recipes people will mix oxides and stains to achieve certain colors, so I think it has a chance! If it doesn’t work, or does but just doesn’t look that great, I know the three firing method will work so since no one else but you has come up with another way to try, I will just bite the bullet and fire three times, but fill up the kiln as much as possible with bisque or test tiles so it isn’t getting wasted, and possibly firing it a little bit hotter at cone 04 instead of 06 may even make the teal darker as well. I have seen teals get much darker, almost black, when going from 06 to 6, and while 06 to 04 isn’t too much of a change it is at least a little hotter. Thank you for the idea.
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On 7/1/2022 at 12:16 AM, Min said:
From reading your first post in this thread my takeaway is you made a Moon Jar shaped vase from lowfire clay that "the bottom cracked and lost large pieces" that you glazed with lowfire commercial glaze. Piece went on to be sold and the customer requested a saucer for it which you will make from a new bag of the same lowfire clay, then after glaze firing rub some black mason stain/frit into the texture, wipe down and refire. You will be firing the saucer(s) in "a very big kiln pretty much completely empty several times for this". Is this correct?
Reason I thought making a cone 6 saucer was a viable choice was twofold, firstly to avoid needing to do a separate firing for the saucer(s) "I’ll be using a very big kiln pretty much completely empty several times for this." Secondly by using a vitrified low absorption cone 6 clay you negate the need for stilting the saucer and glazing it in entirety to ensure it won't weep. I'm assuming that since your customer is using the pot as a planter and is asking for a saucer for it they will be using it as a functional pot and this will be important. Yes, there is some work with getting a glaze match or complimentary glaze colour. This would be my plan B.
How much did the bag of lowfire clay cost? What is the cost of firing your kiln several times pretty much completely empty? Have you tried your lowfire glaze at cone 6 to see if it might work?
Quite honestly I would take the bag of clay and make the customer a new pot that doesn't have the damage the first one sustained during bisque firing. This would be my Plan A. I acknowledge that sculptural work can often have repairs made and those skilled in Kinsugi can enhance a broken pot but from my experience making pots for 30+ years selling a pot with damage such as you described might not be the best idea for what is essentially a functional pot. I can't recall ever seeing a Moon Jar with a saucer as it would distract from the profile of the piece.
As far as I can tell everyone who made a comment about not caring to do custom work is making functional pots. Yes, there can be sculptural aspects to a Moon Jar shaped vase being used for a planter but it's still a functional pot. For the context of this discussion it is a valid comment. I actually started a separate thread here asking about taking on custom work, as someone making sculptural work your comments would expand the dialogue there if you care to post your thoughts there to add to the depth and breadth of the discussion.
Nobody has said yes to your question because nobody has had success with this method or hasn't tried it. I don't think it would work.
The Moon Jar has several chunks missing from the bottom, which the buyer knew completely ahead of time and doesn’t care, it actually provides just about the right amount of space for a planter with should have a hole in the bottom for water to come out so it should work very well. Also he is using it for his “pet” orchid, and orchids, as someone who used to collect them on a small scale, do not require a lot of water, so the saucer is really for him more for decoration and just to make sure even small amounts of dampness or water that flows through doesn’t damage his table. I realize more than he does that a Moon Jar with a saucer will look kind of funny to cermacists, but I believe if I make it to the right ratio it could still look good, you would just be missing the profile of the foot- that is part of why I am doing at least 3 versions of it- partly because they always say for commissioned work that you need to make three versions in case something happens and you won’t delay the order by having to redo it. I will be using a terra cotta flower pot saucer of the right size to help as a mold, then add the matching texture.
I do appreciate why you think doing it at cone 6 would be better, and no I haven’t had the time to try the glaze at cone 6 and see how it looks, in general dark teals in my experience from cone 06 tend to get very very dark, pretty much black, when moved to cone 6 which is why I haven’t tried it. Technically I did not buy exactly the same clay, Continental Clay’s lowfire earthenware is just awful, I had to use it for two sessions of a class, right after the talc mine switch happened and unlike other companies they did not adjust their recipe, so instead of its former brilliant white it was a horribly ugly buff, we all had to put white slip or white glaze on pieces before we could glaze it usually because all the glazes available in that class just looked horrible with it. It also was terrible to use, very short, cracked easily, and was no fun at all- I convinced my mom to do one of the sessions with me and she continued after I left for another session where the teacher, who was very mad at CC for not alerting anyone to the change and they still advertise on their website that is a very bright white. So she switched to a cone 6 stoneware that my mom got to use for the first time something different and was blown away at how much better it was to work with. The other supplier in town, which I fell in love with their clays then made the horrifying discovery that 90% of their stonewares and even all their porcelains weren’t vitrified, most not even close to vitrified, but they had stocked up a lot of their very nice, so bright it is almost whiter than their porcelains earthenware so they could keep selling that while they worked on a talc free recipe that was still very white, and bought that, having heard a lot of good things, but not wanting to go back to lowfire temps as I am much happier with cone 6. I do have some cone 06 glazes that I had bought while in that one class, because they just didn’t have enough options I liked, and then very soon after stopped taking the class (well the teacher kicked me out, saying even though I had only been in the class for two 7 week sessions I was too advanced because I progressed super fast from doing a lot of self-learning, and that I should find classes with more opportunities, which I had already done when she sent me that email. I have taken a handful of classes but am almost entirely self-taught and also draw on my academic sculpture background from 20 years ago when I majored in metalcasting and mixed media sculpture). I plan to use up those lowfire glazes while doing raku, as in addition to actual raku glazes you can use any lowfire glazes and even sometimes use midfire or high fire glazes, although those require some special techniques and will look different as they won’t fully melt.
I don’t remember how much the lowfire clay cost, it was pretty reasonable although as for all clays at MN Clay Co more than what Continental would sell. But compared to all the other clay I bought that I’m very limited in how I can use it because it isn’t close to vitrification and for the porcelain also isn’t translucent like they told me, that one bag of earthenware is a drop in the bucket for me. I can try and fill up the kiln more when I fire it, fire the saucers slightly higher at cone 04 perhaps so they could go in with a big load of bisque…I also bisque at cone 08 for raku and alternative firing, but I worry the glaze won’t melt enough. Otherwise everything else always gets bisqued at cone 04 so I think that should work. The other thing I could do is fill the kiln with a lot, and I mean a lot, of glaze test tiles, as I have a huge amount of new glaze recipes I need to try. So I think either way would solve the issue of firing and almost empty kiln- which I was partly worried about less from wasting energy that I was the change in heatwork that can happen when you under or over fill your kiln.
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Hey, you guys can have a bad attitude about commissions all you want, but I love commissions, with always the caveat that I have artistic control and final say- this is out of the ordinary for me as I don’t make functional work, I am a sculptor, so I would be endlessly happy to get tons of sculptural commissions. I’ve been working on trying to make that a regular thing for me. I’m doing this functional commission plus a set of 4 mugs for him because he is my friend and he bought my first piece, paying me more than triple what I asked for it because he said I needed to charge more for my work. I absolutely do not ever make mugs, I have a firm ban against them, but I’m looking forward to working with my friend to make a set he’ll like, while getting to have a lot of fun with surface decoration. But those will be the only mugs I’ll ever make. Maybe commissions for potters is different than for sculptors, I hardly ever hear other sculptors complaining about getting commissions, most are overjoyed. We in fact frequently are competing for them.
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On 6/28/2022 at 7:02 AM, shawnhar said:
This is what I would do, just hit the bisque with black underglaze as if it were a wash.
That won’t work, I’ve already stated that I tried doing that with the pot, the glaze is very opaque and nothing under it shows through.
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On 6/28/2022 at 6:22 PM, Min said:
Use your cone 6 clay instead of the lowfire and make a coordinating glaze that compliments rather than exactly matches the lowfire one. A vitrified saucer for a lowfire pot.
Special or custom orders tend to come back and bite you.
This is a particularly good friend, so I do not consider that it is biting me at all, I’m happy to make it for him. And I love commissions and wish I could get lots of them- with artistic control. Making a coordinating glaze would take up way more time and make much more work for me than simply firing a third time with a mason stain wash, my only question which no one has answered is whether it is possible to put it on and wipe off the excess without wiping off the base glaze, if I tried to do it in one glaze firing. If the texture were any different I’m sure I could figure something out with wax, but the way this is done I don’t think that would work, or at the very least it would take me endless hours of very carefully painting very thin lines of wax on a rather large pot and it also doesn’t seem efficient. I was simply hoping someone had had a similar experience and managed it in one step instead of two. It doesn’t seem like it though, so a third firing it is. If I did what you suggested, I would also have a 25 lb bag of cone 06 clay that I have no use for that I spent money on, at least this way a good portion of it gets used and I can probably come up with some additional things to make out of the rest of the bag to fire with it. I also would have a nearly full bottle of 06 glaze that would go to waste as well…really not an efficient use of what I have spent my money on, when I didn’t know that I was surprisingly soon be able to fire to cone 8 if I wanted on 3 kilns that I had no idea I would own and be able to have my own studio and be making my own glazes as soon as I was able. My expectations were that I would have to take classes and pay to fire elsewhere and work out of a 4ft x 2 ft space at home for years, I’m very lucky that things changed rapidly and I was able to turn full time professional much faster than anyone could have expected. But that doesn’t mean I’m not going to use up what I bought before. Besides, you haven’t seen this glaze, it would take way more time to make a complimentary glaze that to just do an extra firing, I really am rather surprised that you would think that was a better route.
Kiln build from scratch
in Equipment Use and Repair
Posted
I just wanted to add, I found on the Bartlett website a document on what you need and how to put together the complete controller from what you get when you buy it. Down at the bottom for V6-cf besides the manual and firing profiles they have the connections diagram, which is one of the best electrical diagrams I have seen over the last few months, and the technical manual, which includes some things that would help with putting it all together. https://www.bartinst.com/manuals/kiln In November I think I called them trying to find out about if it was a faceplate or a controller, which lead to a lot of my confusion about things, but the customer service was really nice and I think I might have talked to a tech there, an older gentlemen who has been with the company a long time, so I think if I need help I can probably get some help with putting it together from them. Cross fingers they are like Skutt’s techs.