Glaze testing

Stoneware and porcelain ceramic test tiles ready for glaze

Test tiles ready for glaze

Getting started again at a different temperature requires using all new clays and glazes. I’m testing some commercial glazes to give me a basic palette to work with while I formulate my own to fit my needs exactly.

So I roll out slabs of clay, cut them up into tiles and bevel the edges and cut a hole for hanging on a board later (as a display for reference) and stamp a pattern to test how the glaze is affected by texture. I make two sets: stoneware and porcelain. The color of the clay shows through glazes and will affect the color. And I want to test the fit on each clay body.

After applying the glaze to each tile, I applied the same red iron oxide and rutile again on a different area of the tile, because they will look a bit different whether above or below the glaze.

Porcelain and stoneware ceramic test tiles of Coyote glazes after firing

Test tiles after firing

I fired them like normal to cone 6 in my electric kiln. All of these are Coyote glazes. From the left, they are Black, Shino, Light Shino, Red Gold, Espresso Bean, Really Red, Gun Metal Green, Cedar Shino, Oatmeal and Oasis Blue. I’ve used the black with success on a pot. It’s a good solid glaze. Shino is nice, Light shino is a beautiful creamy glaze on porcelain. Red Gold looks wonderful in this test on stoneware, but not so nice on porcelain. Really Red looks awful as a whole tile, but I’m thinking it would be good as an accent glaze. Gun Metal Green is just beautiful on pots. I can’t recommend Cedar Shino at all. I would say the same about Oatmeal, except that where it borders Gun Metal Green some nice things happen: small blue “flames”. And Oasis Blue is really pretty. It’s quite even and seems very stable.

I’ve saved Espresso bean for last. You can see it’s crawled on the test tile. I’ll have to test this one again, applied more thinly. This particular glaze doesn’t want to stay on the pot if it’s applied at all thickly. It will crack and chip off very easily.

So here it is. I’ve already decided I like the Black, Shino, Gun Metal Green, and Light Shino. You can see these glazes on my pots already. Oasis Blue and Red Gold are maybes. I’m going to try them more on real pots. I’ve been saving them up until I’m confident I have good glazes to put them on.

Unglazed stoneware and porcelain pots waiting for glaze selection

Waiting for glaze

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