float/slump/devit?

Ann Demko · Post by **Ann Demko** » Fri Dec 19, 2003 11:29 am

I am still working on my design for a foundation's yearly award. I have my design and am going to present it in two formats. One clear bullseye with opaque design elements and the other on clear float with the design blasted. I have accomplished the bullseye and I ordered a 3/8" circle of float to slump into a plate mould that will get the blast design. My question, since I am not familiar with float, is will I risk getting devit on my blank during the slump phase if I slump at 1300-1350 degrees. I have read about borax and Spray A but the temps are too low for it to cure. I guess I could use one of the low temp/leaded spray but i really don't want to take a chance on ruining this blank. The fellow that cut the glass at our plate glass outlett also does custom bevels and he outdid himself on polishing the border of this simple blank. It is really beautiful. Thank you. Hopefully I will have a web site after the holidays and will be able to share some of my creations with you all. Ann

rosanna gusler · Post by **rosanna gusler** » Fri Dec 19, 2003 12:06 pm

you should be able to slump at 1260f or a little less. 1300f seems to be the magic devit number in my kiln. remember to go up slow through strain points. rosanna

unicorn · Post by **unicorn** » Fri Dec 19, 2003 8:31 pm

Hi Ya. It would really help to know which was the metal side of the float. If you fire metal side up there is a good chance you'll get de vit. An ultraviolet lamp can be used to determin which is the metal side, but an old glazier told me he could taste the metal by licking the glass, yuk.

rosanna gusler · Post by **rosanna gusler** » Sat Dec 20, 2003 8:10 am

taste it. i am going to have to try that. i bet there is a difference. rosanna

stargazer · Post by **stargazer** » Sat Dec 20, 2003 10:08 am

Licking the glass will not tell you which side of the glass is the tin side. There is only ONE way to determine the tin side, a UV light. If you fire that glass with the tin side up you WILL get tin bloom at 1100 - 1150. (a scummy surface). First determine the tin side with a UV light, then fire tin side DOWN. If you are dropping 3/8" float glass through a drop ring your diameter will determine how hot to fire it. For a 15" - 20" diameter 1230F works great. But it also depends on how deep you are slumping.

rosanna gusler · Post by **rosanna gusler** » Sat Dec 20, 2003 11:53 am

i have a uv light. i am still going to try it. most folklore has some basis in truth. rosanna