fire-polishing float after sandblasting

[Mark Selleck]

After fusing two pieces of float, I decided to sandblast the top surface to eliminate an irregular devit area. To fire polish the surface do I need to bring it to full fuse again, while flat, or can I fire polish during the slump? The sandblast was done with 100 grit, which normally results in a mat finish when slumping at my normal 1250. If I slump as normal, then run the temp up to 1400 AFAP, will I get a fire polish? I'm slumping 1/2" into bowl molds.

Thanks for any input.

[Nelson Tan]

Hello Mark,

I did it while 1/2" green float glass is still flat. 1465 F. 18" diameter while flat.

http://community.webshots.com/user/yamatan
under glass sink


Nelson

[Mark Selleck]

I thought I'd report on the results of my "experiment": I decided to try fire-polishing during my slump of 1/2" float. The piece was made from 3 pieces of 3/16" float, 16" diameter. I slumped into a BE bowl mold at 1250, using the side elements of the kiln, as they are the only computer-controlled elements. After the slump was complete, I turned on my top elements on high, and ran the temperature up to 1400, held 5 minutes, then vented to 1030 and ran the annealing cycle. I was pleasantly surprised with the results: The surface of the bowl isn't as slick and shiny as it would be if brought up to full fuse, but it is not a mat finish either. It has a soft sheen to it that is very nice, and the elements that are fused between the sheets of float are clearly visible. There was no distortion of the bowl. Definitely something I will be doing again if I have a problem with devit in the fusing process. The sandblasted surface shows no sign of the devit that was there before.