Kelly in AK

Seattle Pottery Supply says they have some talc as well. Now, this next bit is information not advice, because I’ve never made kiln shelves and don’t personally know anyone who has. Alumina and zircopax are both highly refractory, much more than talc. My experience (only to cone 6, mind you) is that zircopax sinters together significantly harder than alumina. My opinion is that I would rather chop existing kiln shelves into the shapes I need or buy them than to try and make them. That is, I suppose, because I now have more shelves than I need, and a day job. When I had no money, lots of time and lots of clay, making my own bricks to build a kiln worked out just fine. That was against the opinion of people more knowledgeable and experienced. People can have different opinions and both be right. As for advice I would say first to check if Michael Cardew had anything to say about making kiln shelves in his book “Pioneer Pottery.” You can take anything in there to the bank. Next, find a video of Isaac Button loading his kiln. He made his own shelves. Finally, take a look at Tony Hansen’s Digitalfire website. He’s made his own shelves too. Please let us know how things work out, I’d like to think we’re learning and teaching together here.

In my studio I use a jiffy mixer on a variable speed drill, if it’s splashing I slow down the drill. After it’s all stirred up I use a long whisk to make sure it’s in suspension, like if the bucket’s been sitting still for several minutes. At school it’s toilet brushes and big paint stir sticks. If there’s globs of glaze in the bristles students can see it’s not mixed up well enough. Mixing up new glazes I always sieve it couple times then adjust the viscosity with Epsom salts. That (Epsom salts) has probably saved me more time than anything else. I never have hard panned glazes. At worst it’s a thick gel at the bottom of the bucket, even after sitting a few months. Tony Hansen wrote a nice article on flocculating glazes and adjusting viscosity for anyone not familiar with that. I don’t go to the lengths he does for exactness, but just a basic understanding of the principles has been invaluable.

Students new to ceramics are learning a lot (hopefully!) to make sense of everything happening with this process. It kind of boggles my mind when I think about it. There’s really nothing in anyone’s ordinary experience to compare it to. After years of making pots so many things become second nature we don’t even think about them, but for students even the most basic things are like a new world. The beautiful thing is that it keeps getting better the more you learn. Decades on and I still make discoveries, still have surprises both to my delight and chagrin. I hope I never see the day I open a kiln and see everything looking exactly like I expected it to.

This sounds like a cool thing to explore, I can only guess what might happen. It may effloresce in different amounts on various parts of the work as it dries, which is an exciting thought. People into carbon trapping shinos use this property to great advantage. The other thing is that the soda will go into, not just on, your pot (I sense you already know this), so even if the foot is wiped clean I’d still either wad the work or make sure there’s a healthy coat of kiln wash on your shelves. Oh, and remember the stuff is caustic! That slippery feeling it leaves on your fingers is literally your skin being washed away. Use gloves and safety glasses. I’d love to know how the experiments come out.

I use local Anchorage clay, it’s considered a mediocre red earthenware here, no one really uses it. You’ve got to be discriminating when collecting to get the good plastic stuff and I add 1.5% veegum to help it play nice. Interestingly, at 04 it’s a bright orange, porous, but strong earthenware.. at 03 it is darker, completely vitreous (<1% absorption), and really strong. Like, I drop it on the floor and it bounces kind of strong. At cone 3-1/2 it’s a bloating slumpy mess. This is as opposed to the clay I got from Sheep Mountain a couple hours away. Threw like a dream right out of the bucket. Firing was a different story. Went from earthenware to ceramic foam in one cone. And I mean foam, frothy bubbling foam. Love the Rabbit holes.

It pulls water out of the clay just like plaster and doesn’t warp. I haven’t made bats out of it, so I can’t say much about that, but for ware boards it’s my favorite. The bottoms of pots dry more evenly in relation to the rims. As a work surface I wet it with a sponge to keep things from drying out too fast. I too would like to know if anyone has used this stuff for bats and what their experience was.

I love the stuff. I use 1/4” for ware boards. 1/2” is what covers my wedging table and works great for dewatering slop. Every bit as well as plaster. I did sand the surface of the 1/4” board, it’s kind of pebbly. Also, the 1/4” board gets saturated pretty fast, 1/2” is better for reclaim.

And here I thought I was the only one! I made several molds a few years ago, and still use them. They’re open ended cylinders made from slabs, then a bunch of holes cut into them. About 1/4 inch thick, maybe slightly thicker. Sturdy. Like you guys, I looked at pictures of antiques for direction. I usually make brie, but I did try them in a press a couple times with no problems. I will suggest taking care to make the holes big enough (1/8” drill bit worked well for me) and cleaning the glaze out of them before firing. I’m positive handmade ceramic molds make the cheese taste better.