Monday, January 28, 2008

New Tests

I unloaded the test kiln this morning. Sorry that these pics are somewhat blurry. Hopefully you'll get the general idea.
This first image is an amber glaze. I tested a fritted clear glaze with 2, 4 and 6 % black iron oxide. (left to right) All over a white slip. My original amber was fluxed with Gerstley Borate and I thought I'd try a fritted glaze instead. It seems to have crazed less, although I wonder if I'll get some delayed crazing. Anyhow I like the 4% the best for most purposes, but the other two are perfectly acceptable also.
Next I tried these same glazes over a new green slip. These tiles were dipped in white slip and then the new green slip, part way down. Then the new fritted amber glazes 2, 4, 6 % left to right. I like the one with the 4% over this new green slip. The orginial green had 5% oxide so I decreased this down to 3% after looking at Clive Bowen's recipe for green slip. I do think I could put this new slip on a tad thicker and get more of a contrast with the white. (Notice that little thicker drip on the upper right corner of the middle tile).
Here is the fritted amber with 4% on the left, and the original gerstley amber with 8%. Both are nice and I will use both in this next load of pots to see what I like. I should have tested the fritted amber with 8% but it didn't occur to me at the time.
Some things to think about as I look at these...maybe I could have kept the original green at 5% oxide and it would look okay with the 4% amber. Also, my friend Leon suggested I try a white slip that is more vitreous. So I will work on that for future firings. He thought that may help reduce the crazing and I think maybe seal the body more.

Okay that's it for now. I have a few hours in town, barber, library, post office and a trip to the hardware store. So I better get to work. I am getting ready to fire the salt kiln and a load of earthenware, so lots to do to prepare.