Callie Beller Diesel

I just want to say good for you for including cones to verify firing temps. They’re especially useful whenever dealing with a kiln you haven’t fired before. They’re all a bit different.

Euclid’s is Canadian. They’re a division of Pottery Supply House and are based in Oakville Ontario. The $40 won’t include shipping.

Most often, I’d say 99% of the time, assume recipes are in weight. The only time you usually see volume measurements is if the recipe is an older one from the US (1970’s or earlier), or the end batch size is measured in hundreds of pounds or kg. If the person who originally wrote a volume based recipe was less concerned about precision, variability may have been acceptable, or even desired. Even 20 years ago, almost no one who was mixing their own clay was worried about end porosity. They were concerned with working properties and aesthetics.

Hi and welcome! The most typical issues with glazes in the first couple of years of making pots most often involve how they’re applied. The 2 places to look first are how well the glaze was mixed before it was applied, and how thick it went on. From the information you’ve given, I don’t think your firing had anything to do with it. Your cones indicate the firing was within Amaco’s suggested parameters. With test kilns, you don’t have to go super slow on going up to replicate a firing in a larger kiln, but you should pay more attention to how fast it cools. 11 hours sounds kinda slow for something that small. You could either add another 5-10 minutes to your hold at the end, or try a drop and hold schedule. Unless your glaze bottle was sitting for months and you didn’t shake it well before applying, I don’t think it’s a mixing issue either. That leaves glaze thickness. Most often, you don’t get the colour on the company’s test tile if it goes on too thin. It could just need a third layer if you only applied 2 thick ones. The textures on the sample images appear to be heavily filled in, so that’s what I’m leaning towards first. Make yourself a small test pot with a thin layer, a layer similar to what you did on this piece, and a layer on top of that to confirm. It’s good practice to make sure you put a clay cookie/ waster slab underneath tests like this to avoid scraping shelves later. Especially if you’re ever using someone else’s kiln! The other factor that could be at work is the underglaze you mention. If this glaze is applied over a layer of a dark or blue coloured underglaze, that could also affect the end result.

It should also be mentioned that there’s a narrower window where nice looking and well melted, well fitted glazes overlap at lowfire than at cone 6 or cone 10. The lower you go, the better versed in ceramic tech you need to be to get it to work. You won’t do it just out of the box with commercially made materials.

I agree with Mark and Kelly about remaking the batch being the least amount of work involved at this point. Best case scenario you save some of them, but you’ll have to remake the ones that blistered in the refire anyways. If you have to remake some, you might as well do the batch properly from the start, with fewer headaches. @Kelly in AK, Milestone makes decals specifically for cone 6. Their stock decals are kinda fun and they also will custom print larger batches.

If you’re concerned about the fragility of a sculpture as opposed to a pot, how the piece is constructed is going to have more of a bearing on the durability than the clay body. A thin walled piece constructed with the best methods described in Min’s link above will still break sooner than a brick made using the exact opposite principles. If your sculptures are thin walled and unglazed, making them out of earthenware glazed with a well fitted glaze will add strength, but you’ll still need a lot of packing padding. If your pieces are solid, they’ll withstand more impact. But even construction bricks break if they’re dropped from enough height.

It sounds counterintuitive, but add a bit of zircopax to glazes. It’ll pop the stain colours a bit. 1-3% will do.

Re bucket suspension properties: with recipes like Lynette’s Opal that also contain soluble ingredients like neph sye, if you noticed gelling issues with a gerstley borate version, a frit or borate substitute could alleviate some of it. I say some, because I find frit 3134 is also slightly soluble. Not nearly as bad as GB and it takes longer, but it does happen. After Ferro moved their production to Mexico it took them a while to get back up and running properly. I’ve heard some rumours about first batch quality control bumps that have been worked out. It sounds like they’re re-establishing supply networks, and working on back orders. I would assume that availability of those frits will smooth out before we’re in a substitution crisis again. Something to keep an eye on.

@Mosquito If this kiln only has switches as the OP describes, any value that would be in this kiln is entirely dependant on the condition of the bricks. If there are no big cracks, especially in the lid or base, if the element channels are in good shape and there’s no glaze spills or chunks missing, you could sell this as a project kiln for maybe $50 on facebook marketplace or similar. Include any kiln furniture in that price. Advise any beginners looking for a mid fire/cone 6 kiln that this one likely won’t meet their needs, or will need to be completely gutted to do so. You can try offering the plaster moulds, but if the buyer isn’t interested, just throw those out. They loose some absorbency or become uneven after a number of uses and have no resale value. Just because you mentioned doll making: If your mom used anything like gold lustre, even a partial bottle of that has value. It wouldn’t be unreasonable to ask a pro-rated cost of a new bottle.

Think of using stains the same way you do iron oxide or other colourants. Ceramic stains are pigments that let us get colours that are difficult to achieve, or may offer a much safer way to use oxides like vanadium or cadmium. They’re designed to have low reactivity, which is why they can look kind of flat if a glaze is oversaturated with them, or if it’s used as a sole colourant. They can’t be called completely non-reactive because some are affected by some things while in the kiln, but they’re not affected by things like daylight or air. They can go in slip, terra sig, clay bodies, glazes, all the things. They do tend to be more expensive than just a raw oxide might be because they’re engineered. Using them in large quantities in, say a casting slip, is still going to be kinda spendy, but if they’re 1-5% of a recipe they’re an affordable way of introducing colour to low and mid fire work. Making that coloured casting slip yourself is generally less expensive than purchasing one someone else made. Re colourfastness and ceramics: you’re right about things that survive kilns being fine on the colour front. Fading isn’t really a concern. There’s a couple of specific exceptions to that rule ( copper raku glazes, a glaze that fails a lemon test), but of all the things people worry about in a glaze, colourfastness is probably at the very, very bottom of the list.

I have a 20 yo Brent C that has never needed any maintenance, so I think whatever replacement parts cost, it’s probably worth it. I suspect disposing of this wheel will be my kids’ job when I die. I’ve used a Shimpo/Nidec Whisper, and because I’m used to a hum from my Brent, I found the absolute silence of it a bit weird. But it depends on how much background noise you like when you’re working.

Would a sprayer for kiln wash be less work than using a paint tray/roller? I don’t think I’ve heard of anyone using a spray gun for kiln wash. That doesn’t mean no one does, it just means it’s not common practice. Alumina hydrate has a larger particle size, and that could present clogging issues with the nozzle. But I’m mostly commenting to boost this for others who use sprayers more often.

Hi Santino, and welcome to the forum! The Brent model A hasn’t been made for a very long time, but according to archived posts here, they still sell most of the replacement parts. Given minor repairs, Brents usually outlast their owners. This thread in particular has some good discussions on possible issues getting a Brent A running properly, along with a number of images. There’s mentions of replacing and sealing the plywood deck that will rot with water exposure. @Mark C. contributed a great pic of one that was bought new and looks pristine. He could maybe answer more questions as well. Has your wheel been altered from the original, or does the underside look different than the image Mark posted about 3/4 down the page? The fitting under the wheelhead looks the same as the one under my 20 year old Brent C, so the modern pan should fit. To my knowledge, the design hasn’t been changed. A new splash pan will be very stiff, and needs to be shoved into place with some authority until it wears down a bit. I would suggest that if you (or your student?) are throwing with enough water that a typical Brent splash pan is leaking, you’re/they’re using way too much water. The tray will hold half a gallon at least before it reaches the overlap. Using that much water isn’t uncommon when there’s a very new beginner involved, but it’s something that most people will move away from pretty quickly.

Because I make with a certain amount of consistency for my customers in mind, I will do play sessions like Pres describes as a design session to come up with new ideas, or refresh older ones. Once I’ve picked one or two versions to run with, I’ll make a bunch of copies without having to think too hard about it.

Ferro frits 3134 and 3124 were designed as replacements for Gerstley Borate too. The drawback to using the frits are that you loose the trace amounts of phosphorus, titanium and iron that add more visual interest. Which was the gripe 20 years ago: the substitutes were boring by themselves, and you couldn’t just swap 1:1. Edited to add: the price of freight has been going through the roof for quite some time. I’d imagine that accounts for at least a portion of the price increase. Probably not all of it, but at least some.

Mason stains can be incorporated, but with caveats. Stain particles are larger than ball clay ones, so you have to add stain to Sig after it’s been siphoned. If you add stain before, most of it winds up in the discard sludge. Be aware you will likely have to mix frequently during application to keep everything evenly suspended. But it does give nice results. Also, if you use any sig methods involving ball milling, that can alter several stain colours. It isn’t recommended for encapsulated ones at all.

Prices for ceramic materials will be based off when your supplier bought them and their rate of sell-through, so there does tend to be a lot of lag.

If she’s making a slip out of the same clay body as the rest of the piece, magic water will likely be unnecessary.

The studio I used to go to had a couple of methods, because they had classes, rental hours for more intermediate/advanced folks, and at the time you could rent a kiln* to fire your own work in. In most instances, you had to buy your clay from them and their price included the firing/glazing. If you took a class, a certain amount of clay was included. For those who came in to rent kilns, they charged by kiln volume used. They figured out a charge for a full kiln that included fuel, some tech supervision/loading time and wear and tear allowance. They’d pro-rate the fee based on how much of the kiln was filled, rounded up to the next quarter kiln. Eg, i If you filled 2/3 of the kiln that would cost $80 to fire full you’d be charged $60 for 3/4 of the kiln. The price was the same regardless of end temperature. It made it easy to do calculations on the fly. *you had to first prove a certain amount of technical ability, either by taking classes with them first, or you had to have a ceramics degree or equivalent if you hadn’t. You also had to provide exact clay type and all glaze recipes to the tech. After that, they had figured out the cost of firing each of their kilns, including some markup for wear and tear. After I got my own kiln and could compare notes, they were charging 4x the cost of fuel for an electric kiln. Any accidental glaze runs had to be scraped off by the person who made them, and if a shelf was ruined the renter payed for the replacement.

If you’re wanting to mix a large master batch that then gets divided out, leave out the dry mixing entirely, but weigh the water. If you know how much water went into the batch you can divide it out evenly. If you keep to metric measurements, this will be easier, because 1 ml of water weighs 1 gram. It doesn’t work like that for all fluids, but it does for water. If you are used to using a measuring cup, check how accurate it is by filling it to a given measurement line and weighing it to make sure it’s close enough for your purposes. For instance, if you add 2500 g of water to your 5000g batch, the whole thing will weight 7500g, so a quantity of slip that weighs 1500g will contain 1000g of slip base. (Numbers made up off the top of my head for ease. You may have to play with your water additions to get your consistency right. Just record what you did.) From there, you can add your colourants to portions of your master batch. To mix thoroughly, you will need to use a stick blender that rotates really fast. If you use something slower like a jiffy mixer, you’ll have to let it mix a lot longer to get everything distributed properly. For some colourants that don’t break up easily, you may have to sieve the mix again.

@High Bridge Potterymostly they’re meant for things like antique/vintage housewares and detecting lead paint. They measure anything you can dissolve with the reagent supplied. So if there’s some lead there but it doesn’t dissolve, or if it’s below a certain amount, you could get a false negative from the home kits. They’re only meant for a quick yes/ no answer.

Hi and welcome to the forum! Sorry about the wait, we’re usually quicker than this. The number of pictures you uploaded is 1) absolutely marvellous, and shows all the good details we need, and 2) would have been too many for our server to handle. But in looking at them, I hate to say it, but the person who sold you that should have paid you $75 to haul it away. Cress Kilns is still in business, and still sell A series kilns, but only smaller sizes as testers. They haven’t sold A series as large as yours for a very long time. The serial number on yours says it was built in 1965. The electrics are very outdated, and may have never have had things like relays or switches replaced. Judging by the state of the rest of it, I’d be worried about internal corrosion. Replacing and upgrading the box is a project that people here have taken on with good success, and you mention you have the time and money for it. I wouldn’t have chosen it as a first project, but I fully respect anyone who loves to jump in with both feet. You’d learn a lot. BUT. Before you start, get a lead test on those bricks. Nothing fancy, just a swab from that website we all love and hate. Proceed accordingly.

Price check what they’d cost you from Euclid’s vs from Cress, including shipping and exchange. It might be less to order from Ontario. If you’re having trouble figuring out which elements you need and you’ve got a weird model either talk to Arturo at Cress (some of the others aren’t as knowledgeable) or call Euclids. Either one will get you sorted.

If it’s bone dry and you try to re-wet it, any water applied will work pretty rapidly to dissolve the clay. So surface texture will be altered somewhat. Readsorption may also cause small matrix cracks. If the piece is dear to you and you really feel like it can’t be re-made better, hollowing it out as Pres suggests is an option. The only thing I’d add to that would be to make sure you’re using a drill with low speed. Going too fast can cause structural issues from vibration. You will still have to leave the piece on the thick side to avoid damage, so you’ll have to go really, really slow on the bisque. Allow lots of time for the piece to absorb heat energy evenly. If the piece is truly bone dry and has been for months, explosions from water vapour expanding too rapidly aren’t a big possibility, but breakage due to uneven heating is.