Callie Beller Diesel

M390 changes colour quite a bit between bisque and cone 6. It’s a much darker, warmer red at that temp if aesthetics are of concern. If you like the look of your flower pots as-is, leaving them porous is probably better from a functional standpoint.

I spoke with my supplier last week, and they said that Plainsman has a 4 year supply IF no one hoards it. Mike at Ceramics Canada has said he won’t sell more than a 50 lb bag at a time unless you’ve been making your own clay body with it. So please don’t panic buy. Give everyone ample time to reformulate behind the scenes while still using their current stock.

While I’m one of the first people who will usually say it’s a bad idea to sell crazed functional ware, why are concerned about crazing on sculptural work? Sculptures don’t have the same durability demands placed on them as dishes. They might have their own durability demands if they’re outside, but I digress.

Hi and welcome! Not a silly question at all. The good news is, hot won’t affect materials, but humidity might make a few things like soda ash or dolomite clump. Anything that is prone to this can be dried out on a baking sheet at about 175 F in a kiln or oven if it’s a nuisance.

I don’t know about other lustres, but gold and white gold are made of those actual materials, and don’t tarnish. Some raku glazes that contain a lot of copper can be prone to reoxidizing over time. Usually folks will coat pieces like that with spray varnish or similar. I think it could work for Palladium.

If we’re taking bets, I call iron in the water being the culprit. It’s the one constant variable across all OP’s tests so far. Very interested to see how the distilled water variation turns out.

@AndreaK I think you’re probably relatively local to me, so I assume we’re talking plainsman clay at least. Does the studio you’re looking at do commercial or homebrew glazes, and what kind of work are you thinking you’d like to make?

Ferric chloride isn’t necessary by any means. I haven’t done a whole lot of pit firing, but I did a couple back in college. You can get some lovely variations with terra sig on its own, especially if you’ve got a light and a dark colour to create contrast with.

Probably. Part of the fun of working with found materials is the variability. Sometimes close enough is all that’s needed.

I use a talisman at work, and while it’s great for 10 gallon batches of glaze, it would be wildly impractical in my home studio. The cleanup of the brushes is a pain. I have a smaller sieve that sits in a 5 gallon pail at home, and I use a large round sash brush to push the glaze through. It works pretty fast and cleans up very easily.

Yes. Yes this will affect things. If your kiln is hottest on the bottom and you’ve packed it tightly, but your ware still isn’t getting the heat, the bottom is probably packed too tightly. You may also be going a bit too fast through the middle parts of that firing. 120 C is a really fast rate of climb. And yes, it’s not unusual for a bisque to go for 10-12 hours. Keep in mind the elements aren’t on at full power the whole time. If you’ve got the touchscreen, check out the diagnostics in the last firing. It’ll tell you what your energy usage is. Re: the density affecting the heat: Electric kilns are sometimes programmed to emit more heat on the bottom elements, because heat rises, and they’re trying to avoid cool spots in the bottom of the kiln. They’re assuming people pack it evenly, and they don’t expect consumers to have to compensate their loading habits on a new kiln. If the bottom part of the kiln is packed particularly densely, especially compared to the other shelves, the heat may not have time to penetrate all the way through to the middle of the bottom layer. If the cones aren’t bending on that bottom shelf with a 20 minute soak at the end, that bottom layer and even the middle is probably playing catchup to even hit cone 09. Try slowing your second segment to 90 or 100 degrees C, aiming for the proper cone 08 temperature, and packing the kiln more evenly.

Hi and welcome! It is possible to get durable ware at earthenware, midfire and high fire temperatures, but there are different considerations at each of those points. I won’t use the term food safe, because it’s a bit of a misnomer, and legally only covers whether or not the glaze has cadmium or lead in it. When we talk about glaze durability, we want to make sure that the clay is fired to a point where it would have less than 1% absorbion, the glaze doesn’t leach anything, isn’t crazed, resists both scratching and cutlery marking, and is easy to clean. With earthenware in particular, you have to be mindful of glaze fit, because earthenware clay remains porous when fired to maturity, and many will glaze the piece all over, and use kiln stilts instead of leaving a bare foot. You have to be extra mindful of your glaze chemistry, because the low temperatures tend to mean the fun, pretty glazes can sometimes be prone to scratching because they’re lower in silica and alumina.

If it’s one of those ones from Amazon, you may be out of luck entirely. They don’t have a good reputation for replacement parts or service. There is, however, and old trick you can use that may save you some searching. Place a sponge against the edge of the wheel head, and it’ll absorb most of the slip that flies off the wheel as you throw.

I get mine about 10 boxes at a time and stack it outside the studio door. I go through it at a rate that it doesn't have time to dry out. But I also have the luxury of living in the same town where I buy my clay.

Juried exhibitions or invitationals through galleries have never netted me any sales. They can be a nice ego rub, which has its own value, but that value isn’t monetary IME. Juried fairs or markets however, are a good thing. Juries can help put together a crowd of compatible artists and quality of work, which helps get it in front of people who are interested in such things.