Sunday, October 27, 2013

Gas Kiln Pottery first results

Too long since I did a blog post! Spending more time in the pottery studio since I got a gas kiln - the glaze results are unexpected usually, so I'm trying to go back to first principles and do lots of test tiles.  Which is pretty boring, but I'm throwing away fewer pieces.  Still just using Southern Ice Porcelain, but I'm down to my last bag now - I need to resist the lure of something new when I can't control what I do now! Here's some recent results -
1) Bowl with reactive slip which was always mud brown in the electric kiln is really dramatic with gas.
2) Glaze that was celedon green in oxidising electric kiln is red in reducing gas kiln - but only on one side!
3) Black stain in porcelain slip then carved and glazed in matt glaze has interesting foggy/fuzzy edges
4) Most of the underglaze oxides are predictable, e.g. cobalt blue, but chromium oxide just turns baby pooh brown instead of green - which I now have read is do to the ball clay in the matt glaze. Really ugly!
5) Billy's now finished my pottery studio extension to house the kiln but here it was before the building went up around it and full of test tiles.  Its a bit scary to light it, and I'm struggling to see the cones and know when to adjust the flue, but hopefully more experience will help.

1 Reactive Slip
2 Derek Emms Copper Glaze
3 Black stain porcelain slip  

4 Underglaze colours
5 Boring test tiles