I found when you pre-polish
I found when you pre-polish a piece with a fine grid sponge or grinder – or you sand blast it, polishing can already happen at around 1250 F. I show some basic polishing techniques in my introduction to glass fusing – essentially it is always the same – no matter if you are using hand tools or machinery – you start out with 400 grit sanding material and work you way up to 2000 grit and the final polish would be a slurry you are making with water and cerium oxide – which takes forever. I love fire polishing – for the final step. The slurry makes a lot of mess and takes forever.
petra kaiser – http://www.kaiserlee.com