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Hulk

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  1. Like
    Hulk reacted to Mark C. in QotW: What are the steps you take after glaze firing with each finished piece?   
    Rub the bottom of pieces as we unload them with rubbing stones. Feel them and look at them for flaws. The more we handle them the more we can find. Put like forms on tables. 
    I grind any that need it during this unloading time. Brass wire wheel and flat forms that are made with 1/2 and 1/2 to smooth.
    fill orders from the pots on table and put the rest in like forms boxes for later orders
    If a show is involved I price and pack the boxes full and put in van 
  2. Like
    Hulk reacted to rox54 in QotW: What are the steps you take after glaze firing with each finished piece?   
    What Hulk said as well! I photograph before pricing because now I make the price visible as opposed to putting it on the bottom. I used to think having the customer pick it up to see the price might help sell it, but why have them pick it up if they aren't gonna like the price anyway? I  would be interested in how everyone polishes the feet on their wares. I usually just be sure to smooth the feet before the bisque fire, but would like to refine that post glaze fire.
  3. Like
    Hulk got a reaction from Rae Reich in QotW: What are the steps you take after glaze firing with each finished piece?   
    Unload, inspect, polish feet, wash, price, photograph, store/stack/deliver.

    I inspect as part of the foot polishing step.
    I try for a time when the natural light is good, and the weather allows rolling up the door for more sidelight. Good light really helps.
    I pull the OptiVisor down for a close visual inspection, pick up and put down the ware several times, wave them about - checking heft, balance, feel - then flip up the OptiVisor and polish the foot.
    The ware that doesn't make a-1 may go to the discount collection, our own kitchen, the to be drilled for planter queue, else smash and trash.
  4. Like
    Hulk got a reaction from Pres in QotW: What are the steps you take after glaze firing with each finished piece?   
    Unload, inspect, polish feet, wash, price, photograph, store/stack/deliver.

    I inspect as part of the foot polishing step.
    I try for a time when the natural light is good, and the weather allows rolling up the door for more sidelight. Good light really helps.
    I pull the OptiVisor down for a close visual inspection, pick up and put down the ware several times, wave them about - checking heft, balance, feel - then flip up the OptiVisor and polish the foot.
    The ware that doesn't make a-1 may go to the discount collection, our own kitchen, the to be drilled for planter queue, else smash and trash.
  5. Like
    Hulk reacted to LeeU in QotW: What are the steps you take after glaze firing with each finished piece?   
    What he said (Hulk). Except I don't touch anything until the whole load has been spread out on my work table for a couple of days. I might go in and pet them, but no finishing-if any is needed-until I've spent a day or so getting over-oh, I hate that, or oh, that's not what I wanted, or any other form of oh, throw it out. Inevitably that is usually premature and even the uglies may be redeemed w/a refire. So I let it perk a bit until I can be more objective. As w/Hulk's dispatching of the not-A- work,  I do the same, and pitch most into the Meet Mr. Hammer bin.
  6. Like
    Hulk reacted to Pres in QotW: What are the steps you take after glaze firing with each finished piece?   
    Hi folks, I have been working in the studio of late finishing up some pieces for next years communion sets, and doing some cremation urns for relatives. One of the jobs always on the finished glaze ware is to handle them feeling for sharp spots, rough edges etc. I have come to always use a diamond disc now on the bottom of the pieces to make them super smooth. As my pieces now are mostly footed except for mugs, the bottoms are glazed with clean foot rings. I also break the foot ring line with 3 cuts from a 1" pipe so that water will drain in the dishwasher.  The final work on any pot is the feeling and the grinding! 
    QotW: What are the steps you take after glaze firing with each finished piece?
    best,
    Pres
  7. Like
    Hulk reacted to Dunkirk Ann in Sculpture Repair Question-Dunkirk Ann   
    After bisquing, the hare is 16 inches high to the tips of his ears. His hind foot is about 5 inches long.
    So, I got the foot to adhere by spreading a very thin layer of 850 paper clay to the 850 non-paper clay leg where the foot attaches. 
    Indeed, I was concerned about the different shrinkage rates. In the bisque, the foot, which had been firmly attached, did develop some cracks where it was attached, but did not break apart entirely. The hare was loaded into a soda kin today. He's in a location that will get very hot, and get hit hard by soda. I'm hoping there will be some fusing and /or melting that will take place. I'm also expecting to have to do some filling in with epoxy mixed with a stain that matches the clay body. 
    So, if I had it to do over, I'd probably build a separate new foot out of the original clay body and fire the foot along with, but separate from, the hare, as Rae Reich suggested. Thanks!
     I'll  update after we open the kiln next week.
  8. Like
    Hulk reacted to Mark C. in Have a new kiln and today I hit a new milestone   
    Ok my reduced gas line to new kiln was unable to fire the new kiln and it shut off at 2100. I fired the other two kilns. Today I fired that Geil kiln off in 8.5 hours to cone 10. Paul Geil expalned the pipe size issue and my 1 inch flex is on the way from Supplyhouse.com.
    I will see those pots on friday as that kiln is super insulated and is a two day cool like all my kilns now.
  9. Like
    Hulk reacted to Morgan in Laguna 15 cracking   
    Sorry, but yet another update that I hope helps anyone else that goes through the headaches I have gone through with this clay body.

    So, all of the suggestions in this thread did help, the wedging, the compression direction (slow drying vs not) etc but I still found I was getting a 5-10% crack rate. Very minor, never through, but nonetheless present.

    That said I have gotten this to 100% success rate adding a few more steps into my routine so I hope this helps.

    First off, as many have mentioned, lets assume you have consistent thickness in your bottoms and forms, wedged well. From there two things seem to be the game changers for me. Instead of just compressing out > in, it seems the clay really loves to be forcefully spread in > out, then forcefully out > in. Take your time with this, I start my forms with a rather thick bottom and by the time I am done really compressing in both directions it is the right thickness. The last thing I do is when the pots are leather hard, if not a bit before, is use a tool of some sort, a spoon will work, a sponge stick, your finger, whatever....and compress manually outward in with said tool. With these two additions I have fired over 200 mugs with zero cracks.
    When I say forcefully above I mean really forcefully. The way I came across this was by making some plates, which I laughed at while making, thinking of coarse a plate would crack. When I make plates I use a ton of force with my fist getting it wide, then compress in to even the surface…wouldn’t you know it, no cracks.

    Hope this helps to those dealing with this in the future!
  10. Like
    Hulk reacted to Min in "Pay the Rent" Blue glaze with even coverage   
    You want to look for a stiff glaze (little glaze mobility / fluidity) if you don't want it to break on edges. Think of majolica type glazes, they are high in alumina making them a stiff non fluid glaze so when the overglaze brushwork is put on the designs don't run or move. 
    If you don't want to use talc then try your hand with a glaze calculator tool, like the free one on Glazy, and have a go at removing the talc and supplying the now lost magnesium with dolomite  instead. You will have to tinker with the amounts as it isn't a 1:1 swap then will need to rebalance the remaining oxides in the formula. 
    I had a look at Tom's Lakeside Blue recipe above, couple thoughts about it. First thing that jumps out at me is the gum in it, I'm guessing it's there because the glaze might have a tendency to crawl without it due to the super high amount of epk. (Epk shrinks as it dries, excessive shrinkage = cracking which more often than not results in glaze crawling during the glaze fire). Bit of a band-aide solution to add gum when supplying part of the epk through calcined epk is simpler. Other thing is the colourants are included in the total, not as an addition. Makes it easier to adjust a recipe if the colourants are a separate addition from the main recipe. If possible I would reduce the cobalt, using less of a transition metal  is preferable if the colour is still okay.
    I redid the original recipe first with just replacing the talc with dolomite to supply the magnesium. Then I took that recipe and replaced about half the epk with calcined epk. Glaze with the calcined epk is going to appear thinner in the bucket with the same amount of water. (measure specific gravity) I didn't include the gum in the recipe as it doesn't contribute to the fired chem. If you try this please just mix up a small test amount first as what looks good on paper doesn't always translate to a pot. 

  11. Like
    Hulk got a reaction from Rae Reich in "Pay the Rent" Blue glaze with even coverage   
    I'm using Lakeside Pottery Clear Blue; it goes on and fires well, does not move much, and is fairly consistent over edges.
    The formula is on Lakeside Pottery's website; it's been copied to Glazy as well:
    Clear Blue | Glazy
    It does call for Talc.
    I'm using the no longer widely available C-98 talc, and have enough to last several years, however, if/when the supply runs low, I'll be testing alternative sources of MgO, an important part of several glazes I use and really (really!) like...
    There's some lightening at the edge of the knob, which may be difficult to avoid with any transparent blue over white clay; any road, it lays flat and doesn't move, excepting if put on very thickly.

  12. Like
    Hulk got a reaction from Roberta12 in Green Spots in Italstone ceramic kitchen top   
    Hi Johnny, welcome to the Forum!
    The product is "... technical porcelain stoneware.." slab?
    Which product/finish? Looks like there are only a few that are one solid color, the others have a pattern/variegation.
    All the Calacatta in the catalog ("Book 2023") have some variegation.
    Any road, consult with the installer and/or product rep might be in order.
    My guess, it would be possible to stain the material, however, looks very stain resistant.
    Is the material matte or polished finish? Was all the cutting/polishing dust buffed off?
  13. Like
    Hulk reacted to Mark C. in Have a new kiln and today I hit a new milestone   
    Well I spent 5 weeks this summer getting ready ,pouring a 2.5 yards concrete pad ,moving  kilns around and bringing a new used 18 cubic foot Geil into the mix -got it all vented and organized did the 1st bisgue in the Geil a few days ago and today I have all three kilns glaze firing a 12 cubic and 18 cubic and a 35 cubic car kiln. I'm a bit worried the gas system may be streched to thin volume wise (all two inch supply) and we shall see later today.I have not had a new gas kiln here for about 4 decades. I have a few unresolved issues with the Geil like new 14x 28 advancers that I yet do not have. I'm firing 3 typrs of sheles in that geil thaty came with it.
    The hollow core type -4 brand new and they will warp soon at cone 11,4 old style silicone carbide which will warp soon as well . (I fired this style alot in the 70s -80s but not since then have I used them and the cheap Chinese recystilized sic shelves which will warp soon as well.I need to order about 14 of the advancers  which will cost as much as the kiln did (6K). I keep reminding myself I'm slowing down.
    all this will equal 664 cubic feet of glaze wares-I hope the Geil helps with my rutile pitting issue I have been fighting with all year. 
    On the pitting issue many I know are struggling with the same rutile issues as well currently . I have used rutile for 50 years an seen alot of woes with it but nothing like now.
    all three kilns have oxy probes and I can tell easy about reduction atmospheres in each.
    I have my only art fair this year coming up this weekend (its my 49th annula show  there) and am almost done packing up a huge wholesale order (20 banana boxes which will fill our Forester Subaru).
    I'm working hard to get out of the country for 4 weeks of diving in Indonesia soon-I know tough life
  14. Like
    Hulk reacted to PeterH in Positive about failing elements.   
    I expect you are right that it doesn't contain any "smarts" for minimising the effect of failing elements.
    PS What information I found (but haven't read in detail)
    I think that the CE is just an indication is passes European community standards
    CE marking for Electronic equipment - EMC testing
    So your controller is probably a Stafford ST316B.



     
    Data sheet, installation guide and user guide at https://staffordinstruments.co.uk/st316b-controller/
    Site https://staffordinstruments.co.uk/
    Contact https://staffordinstruments.co.uk/contact-us/
  15. Like
    Hulk reacted to neilestrick in Positive about failing elements.   
    While ailing elements may still do the job, albeit more slowly, keep in mind that those firings are costing you more than with fresh elements. I once ran my e18T-3 until the elements would no longer reach cone 6, and the last firing cost me twice as much as the new elements. Also, elements that are used to the point of failure are generally more difficult to remove because they are deformed, and because they coils tend to expand in diameter as they wear out. In non-L&L kilns that means they'll do more damage to the element grooves during removal, and in L&L kilns it means they tend to break into small pieces as you remove them, therefore taking a lot longer to do the job. Although changing elements may be a miserable job, it's a lot easier to do it before the elements get really bad. Replace them once the resistance is 10% off from new, or the coils start to lay over on each other.
  16. Like
    Hulk reacted to Min in Positive about failing elements.   
    Just adding one point to Dick’s great post. If you use a custom ramp schedule, with some controllers you can still program in a specific cone within the program. ie X degrees per hour up to  a  specific cone then continue with the custom program.
  17. Like
    Hulk reacted to Dick White in Positive about failing elements.   
    Oh no, Babs, don't fail on us now, we love you and need you. So, what did I ever write about elements and glazes... where do I begin...
    A cursory review of the infamous Orton cone tables shows 3 columns of temperatures for each of the basic types of cone. The first column of temperatures is for a slow ramp over the last 2 hours into the final temperature, the middle column is for a medium speed ramp into the final temperature, and the third column is for a fast ramp into the final temperature. A slow ramp will bend the cone at a lower final temperature than a fast ramp, as a fast ramp must continue to a higher kiln temperature before the heatwork has penetrated the ceramic and the cone bends. Elements, as they wear out, produce less and less heat, which means the kiln will heat slower and slower (i.e., take longer and longer), particularly at the higher temperatures of mid-fire and high-fire clay bodies and glazes. A Bartlett or Orton kiln controller (Skutt controllers and the L&L DynaTrol are private label Bartletts, and the Paragon Sentry line is a private label Orton) that is programmed using a custom ramp-hold sequence to finish at a particular ramp rate to a particular temperature will continue to fire to the assigned temperature regardless of the actual ramp rate the elements can achieve in their weakened state (until the elements are so weak they just can't manage any increase in the kiln temperature, and then you get the dreaded E1 failure). Thus, if you are running a program with a set point of 1222℃ at 60℃/hour expecting it to produce a nice cone 6 per the Orton chart - but your elements are so worn that they can only manage 15℃/hour at the end - the kiln still will go to 1222℃ because that is what is programmed, but at the slower rate because that's all the kiln can do. Looking further in the Orton cone table, 1222℃ at 15℃/hour is cone 9, seriously overfired. (I'm just pulling these numbers from the table for the purpose of discussion, your studio practice and kiln condition may be different.)
    All that said about custom ramp-hold programs, there is the other side of the Orton and Bartlett controllers - the cone-fire method. You enter a speed and a cone number via the keypad, and the controller knows what to do. The cone-fire method on both these controller types contains some hidden adaptive programming that monitors the actual ramp rate in the final segment in real time. If the kiln is lagging, the controller will adjust the set point down using a proprietary algorithm from Orton so that a proper bend of the cone will occur at an appropriately lower final temperature. Using the above example, if you have set a cone 6 medium speed firing, but the elements are so worn they can only manage 15℃/hour at the end, the controller will stop at 1185℃, 37 degrees early, for a perfectly bent cone 6. Similarly, if you set a fast firing and your elements are still sufficiently robust to accomplish the higher ramp rate, the controller will automatically proceed to a higher temperature.
    Note that this adaptive behavior is only available in the cone-fire method. If you are using custom ramp-hold programming, you need to watch your cones and adjust your final set point to match the cone behavior. And when you install new elements that can actually maintain the ramp you set, you need to watch your cones and adjust your final set point to match the cone behavior. But alas, I repeat myself.
    Keep calm and carry on. Especially carry on .
  18. Like
    Hulk reacted to Babs in Positive about failing elements.   
    My elements are failing, oy about half an hour to an hour longer. I have ordered new ones, over $1000 Aus. , an increase of over 60%
    My least favourite job is element replacing followed closely by shelf grinding, more confident shelf grinder... Anyway , rising in the night to e there when kiln shuts down, I remembered reading sthing that @Dick White wrote re glazes maturing in a failing element situation. SO, sorry @oldlady, starting with a So, and plus I wanted to return to bed, I switched off about 1180 instead of going through to end.
    I already ramp 80°C for final hour but on opening kiln, perfect, glazes loved it and no shelf drips from usual customers!!! Now toying with new elements, less electricity used with the present setting, albeit for just a while.
  19. Like
    Hulk got a reaction from Rae Reich in QotW: Given a new 15 X 20 space for a studio, what would be your first 5 things to do to it?   
    We had baseboard heaters in the first house we bought (some thirty years ago). We took them out, added insulation to the overhead, insulated the floor, added cellular blinds, got a more efficient/modern wood stove, and cut lots of firewood. We were trying to keep our electric bill down*.
    Any road, with "strip heat" (aka resistant heat, metal that heats up, like our electric kilns) we get out about what is going in, hence, add more watts to get more heat. My guess is the same wattage heaters heat about the same, whether baseboard, portable, etc. The direction/focus of radiant heat, however, that's a comfort factor, as Min points out!
    I'm still planning on a heat pump for the new Studio space (we moved this year).
    It will cost, up front, however, more efficient in the long run**, does both cooling and heating, and we'll size it to handle the extremes, hence it'll be chugging easy most of the time.
     
    **aka "mini-split" - the units move heat, which takes less energy per unit of heat than "generating" heat.
    The newer/better units heat well even when it is very cold outside...
    *electric where we are has gone up  more, faster, this last year than ever!
  20. Like
    Hulk reacted to Chilly in Clear Glaze Application   
    It depends.....  Some people are heavier appliers than others.  Commercial glaze usually says apply 3 coats.  I have seen people apply three coats that look like my 1 coat, and others whose 3 coats would puddle all over the kiln shelf.
    At our community centre, I get newbies to do a "number of coats" test tile, before they do any glazing or underglazing.  A square tile of clay, marked into 4 smaller squares.  Corner 1 gets one coat of underglaze, corner 2 gets 2 coats, corner 3............etc
    This gets bisque fired and then they apply 1 coat of clear on half of corner 1, 2 coats on half of corner 2..........
    Second fire to earthenware, (we don't do any high-fire) then they (I) can determine if they are a light applier or a heavy applier.  This gives them a guide for future applications.    
    We often repeat with a vertical tile with texture.
  21. Like
    Hulk reacted to Callie Beller Diesel in Clear Glaze Application   
    The maddening answer to just about everything in glazing is “it depends.”
    IF it’s available to you, clear glazes are usually much easier to apply thinly and evenly via dipping. If it’s not, then brush away. 
    If you’re mixing 2 glazes, this can often result in special effects that are partially due to running. When starting out you might only want to apply 3 layers in total, however you want to divide it out. Usually you don’t need a clear glaze over other glazes, unless you’re hoping it’ll do something interesting. If that is what you’re going for, make sure you have a waster or a cookie under your piece to catch any drips. Cleaning kiln shelves is not fun!
     Learning how to apply glaze is another skill that takes experimentation and practice to get the hang of, and it’s a good idea to do some test tiles before you start glazing your favourite piece. Recommendations on the label should be considered starting points. Your idea of a thick coat and someone else’s might not be the same thing, and you have to play around with it a bit to find your sweet spot. 
    Generally clear glazes want a thinner application than other things for best results. An overly thick clear glaze will go a bit cloudy. This effect is more noticeable on dark clay or underglazes than it is on lighter coloured things. 
     
  22. Like
    Hulk reacted to Singing Pond Farm in Considerations for kiln unconditoned space   
    Thank you for sharing your experiences and suggestion for the downdraft vent, it's much appreciated! And yes, clearance will be important, it's a 200 year old barn and I hope it will outlive me too!
  23. Like
    Hulk reacted to nellhazinski in irregular cracks on fired cone 10 pots   
    I want to thank everyone for their responses.   Very helpful.   I actually have the Hamer book and the section on cracks is great.  Years ago,I used the formula "Rhodes" celadon for my blue celadon glaze. This glaze has a lot of Cornwall stone, which I thought may be the problem.  It started to craze in the manner I described, so I increased the silica, but the problem persisted.  I was frustrated and chose to  test other celadons, and found another beautiful one, which is the one I am now struggling with.  This may be a silly question, but does the addition of bentonite lower the COE of the glaze?  This glaze sinks to the bottom almost immediately when mixed, so I've been adding perhaps too much bentonite.
    I'll be researching on Digitalfire per Hulk's links.   Thanks so much for these.  
  24. Like
    Hulk got a reaction from Pres in irregular cracks on fired cone 10 pots   
    Where there is a very slight difference in COE, a thicker glaze might show a crack where a thinner layer wouldn't (depending on some associated factors...).
    COE is fundamental to combating crazing!
    Materials expand and contract as they heat up and cool down, respectively.
    Where clay and glaze expand and contract at rates that are different (enough), problems happen!
    At one extreme, bits of glaze pop off the work, shivering, and at the other extreme, the glaze cracks, crazing.
    Crazing can be ameliorated by changing the glaze formulation/composition, also by using a different clay.
    You'll hear and read the term "fit" and "glaze fit" - where the glaze "fits" the clay, there aren't shivering or crazing problems.
    Here's links to some articles:
    Co-efficient of Thermal Expansion (digitalfire.com)
    Glaze Crazing (digitalfire.com)
    ...and a few threads from this Forum:
    Crazing Clear Glaze - Clay and Glaze Chemistry - Ceramic Arts Daily Community
    Crazing question - Clay and Glaze Chemistry - Ceramic Arts Daily Community
    The cracking depicted in the OPs image (first post, above) seems a special case to me - typical crazing forms a pattern, where a large pattern indicates a closer match than a fine pattern. I'm curious to know if the clay is cracking, or is it the glaze?
  25. Like
    Hulk got a reaction from Rae Reich in Mixing Blick Stoneware   
    Hi Tbeans,
    Welcome to the Forum!
    Good questions.
    Drying the slurry to the desired consistency could be an approach; ladle off the clear water, mix thoroughly, then dry*.
    Several clay vendors sell powdered clay - saves on shipping costs - however, the clay you end up with, very likely, will have different properties than what you started with.
    You might get in touch with local and/or preferred vendors to inquire about dry/powdered stoneware.
    I know I've seen dry clay offered by vendors in California.
    Aha! Here's an Idaho store's page featuring some Laguna Cone 5 clays, fifty pound bags 
    50LB Bag Dry Clay – The Potter's Center (thepotterscenter.com)
    Whether you dry out what you have, or add dry stoneware to it, either way, you might start with a sample, then test its working properties, how it fires, how it takes your glazes and finishes?
    Same as for any unknown/new clay, test to see how it works!
     
    *There are several methods for drying out sticky wet clay.
    I ladle the goop onto plaster slabs, then turn and wedge it periodically until it is ready to bag.
    I've seen and read that others bag the goop in tied off jean legs, into pillowcases, et cetera...
    It's a bit of work, however you go about it!
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