float fusing question

bkrgrl@aol.com · Post by **bkrgrl@aol.com** » Sat Feb 28, 2004 11:04 pm

Hi, I am new,learning and experimenting. Using float, mica's and copper. I notice that when I put a clear cap on float, and full fuse to 1465 and hold 10 mins. the edges of glass are not fused together. You can still see two distinct edges and feel them as separate. Do I need a higher temp. with float or a longer soak. I would like my edges to be nice and smooth and all one. One other question, after I fires it a second time-I slumped it in a ceramic mold. The back was very shiney, but, the front was matt finished. Not unattractive, just different. Was this the tin side you talk about,that I should not use? or devitrification? (spelling!) thank you for advice Gayle

Mary Kersey · Post by **Mary Kersey** » Sun Feb 29, 2004 9:02 am

Soak for at least 55min. This will spread so if size is an issue, cut glass smaller or block up edges. Use a clear coat or Borax solution to prevent the devit on surface. Tin side down only helps prevent sticking to kiln shelf.

Tom White · Post by **Tom White** » Sun Feb 29, 2004 10:34 am

1465 seems a bit low for full fuse with float. I need at least 1500. Try 1500 for 10 minutes and see if it works for you. Each kiln is different and you have to find what works in your kiln.

Best wishes,
Tom in Texas

Bert Weiss · Post by **Bert Weiss** » Sun Feb 29, 2004 10:43 am

The issue is one of "heat work". This work can be accomplished by either time or temp. Personally I don't like to go hotter than 1435, so I would soak longer like Mary suggests. I have found that working on a brick floor with only 1/4" of fiber paper between the bricks and glass yielded an edge that is perfectly fused. Your thermocouple placement can be a factor in these parameters. Test and do what works for you.

Lynne Chappell · Post by **Lynne Chappell** » Mon Mar 01, 2004 2:33 am

Bert, do you use an overspray? I had thought that devit was less likely if you went quickly to a higher temperature, rather than soaking for a long time at lower temperatures.

Bert Weiss · Post by **Bert Weiss** » Mon Mar 01, 2004 9:51 am

Lynne Chappell wrote:Bert, do you use an overspray? I had thought that devit was less likely if you went quickly to a higher temperature, rather than soaking for a long time at lower temperatures.

Lynne

I only use borax on 1/4" or thinner glasses. I don't get much devit on thicker glasses with a few exceptions, always involving stainless steel bowl molds. I don't understand that phenomonon.