Gifts from the glaze bucket

My home pottery studio is on a screened-in porch, so anything that can be negatively affected by freezing temperatures--e.g. wax, bagged clay, glazes--usually gets moved to the basement by early November. Sometimes even the basement isn't warm enough to prevent problems like the one presented below: crystals that precipitate out of glazes, particularly glazes that contain lithium carbonate. Given all of the ingredients sharing this particular glaze bucket, I can't say for sure what lithium compound stars in the videos, but it sure is purty.



One more quick video, because the crystal shown therein is so perfect:

Shino tests

I'm teaching a glazing class at Claymakers, and we're focusing on American carbon-trap shino glazes fired to cone 6-7 in Claymakers' gas kiln. Carbon trapping happens thanks to soda ash dissolved in the glazes. As a glazed pot dries, soda migrates to the surface and crystallizes. These crystals can bind with soot that's produced by the reduction (low oxygen) atmosphere in the kiln, yielding smoky grays and blacks, on top of the whites and oranges typical of shinos. Wax resist swooshed onto the drying glaze prevents crystals from forming where the wax is, but can also encourage crystal formation along the edges of the waxed areas.

Here are some of my pots from our first firing; we'll fire again next week.

Malcolm Davis Shino with 6% Redart. The swoosh and dots are from wax resist.
The glaze was thick, and the pot was in a heavily reduced spot in the kiln.

Three salt rocks: Dresang Shino, Malcolm's Shino w/Redart and Carbon Trap Shino.
The swooshes, dots, and squiggles are all thanks to wax resist.

Cadogan teapot (a lidless teapot that fills from underneath, like a salt rock
with a spout); Malcolm's Shino w/Redart, wax resist. The pot was next to the jar in
the kiln, so well reduced, but the glaze was thinner--thus not as intensely black.

More double-walled camellia bowls

Testing out assorted glaze combinations on double-walled camellia bowls. Here's a keeper:

scmw/wb/jjfw

Same bowl, different angle

The blue and white bowl below has white-on-white crystals that aren't showing up well in the image. Unfortunately, the bowl also has two thin cracks in the bottom. The cracks don't affect the functionality, but they make it a second.

scmc/bbg/w/jjfc

Reduction

I've been getting satisfying results with sprayed glazes, and the process has been helping me really appreciate my electric kiln--to the point that (hard to believe) I've been declining occasional access to soda and wood firings. But every once in a while, I glaze a pot for the gas kiln at Claymakers, and the results make me covet reduction firing again. Case in point: I really like the carbon-trap halos around the wax-resist dots on the shino-glazed bottle below. On one side of the bottle, the halos are black; on the other side, they're orange. (The bottle started out as a bottle demo, then turned into a darting demo. I'm not sure why I stuck a horn on it, but it does make a nice place to put a thumb.)

Double-walled bowls

I'm not usually good at commissions, but last month someone asked me to make her a double-walled bowl and it started a nice run of pots. I was surprised to discover what a few years of throwing zigzag pots has done for my skills when I actually get to compress the outside of a stretched pot. By fortuitous accident, one of the first bowls ended up with the inner bowl off-center from the symmetric outer bowl. I liked that asymmetry, so I came up with a way to make intentionally off-center bowls on the wheel.

The first bowl below is symmetric by accident (the result of fixing an unintended ding); more fun to make were the less symmetric ones that follow. I like that the bowls look substantial but weigh surprisingly little. I haven't decided yet whether to call them camellia vases or skeeter breeders. The glazes were sprayed and the pots were fired to ^6 in oxidation.

SCMW/Straw/ASG (dipped)/JJFW

SCMW/Straw/JJFW

SCMC/Cornflower/Selsor Oribe/JJFC

(With camellia for scale)

Straw/JJFW

JJFC/Chun/Straw/JJFC

Lessons from the spray booth

Well folks, I've finally done it! Thanks to a grant from the Durham Arts Council, I have, in the past few months:

• organized a space in the basement for storing glaze chemicals and mixing glazes (which involved removing a lot of junk, and nudging S to organize his hoard. Despite adding a few hundred pounds of raw glaze chemicals, the basement is now a far far safer place than it was previously);
• purchased or collected the necessary equipment for mixing glazes (buckets, jars, sieves, scale, scoops, cabinet, drill & mixing extension, table, etc. etc.);
• replaced the homemade spray booth that S designed for me from a 45-gallon chemical storage keg (a cool idea, and much appreciated, but tiny) with a much more spacious, easier-to-clean, affordable booth I nabbed from a potter who was closing up shop;
• and reorganized my porch studio to accommodate the spray booth, which was originally supposed to go in the basement, but--ha--it wouldn't fit through the hobbit door; so we decided to put it on the front porch, but it wouldn't fit through the human door either; so S took out a screen panel, and we lifted the booth over the railing into the porch studio and re-installed the screen. That was some unexpected fun.

Finally, finally, I spent last weekend in the basement hanging out with the camel crickets and the mosquitoes, mixing up glazes.

And then, finally, finally, finally, today, I plugged in the compressor and the hood, hooked up the sprayer, and set to work.

Here is what I have learned so far:

Lesson 1: Before spraying, you're supposed to make sure your glazes are well sieved, lest they clog up the sprayer. Something clogged up my sprayer almost immediately, but it wasn't the newly mixed, freshly sieved glaze. I noticed little black threads accumulating in the sprayer nozzle. I took the nozzle apart and discovered the problem. Turns out, ants are not well sieved. They come through the nozzle in little shredded bits of abdomen, legs, and who knows what. There were about one and a half survivors; I'm not sure how many casualties there were. It has never been my practice with other spray booths to check for ants in the hosing first, but from here on out, it will be part of my plan.

Lesson 2: The compressor draws too much current and keeps tripping the circuit breaker. This is very annoying, and more than a little disappointing on Spray Booth Grand Opening day.

Lesson 3: Spiders loooove bisqueware. There is no better place to start a web than on a bisqued bowl that is about to be glazed. The more recently the bowl has been wiped down, the better: there's no time like the present!

(Since I'm sharing bug lessons, I should add that the dried up palmetto bug that fell off a greenware bowl into the bottom of the kiln on Sunday combusted 100% at cone 06/1824^oF.)

Now I shall eat lunch.