draping problem

Kim Bellis · Post by **Kim Bellis** » Tue Jun 17, 2003 11:49 am

Hello everyone - I am having a problem with draping a piece of 3mm 14"x10" (approx) over a BE lamp forming mold 8740. I center my glass over the mold - keep the lid of the kiln propped up about an 1" or so and fire slow - by slow I mean 500 dph. My problem is the glass breaks down the center before the kiln reaches 500 dph.

My kiln is a top loader with the elements on top. Does anyone have an idea on what I am doing wrong?

Appreciate the help

Kim the glass addict

Tony Smith · Post by **Tony Smith** » Tue Jun 17, 2003 11:58 am

You didn't say how deep your kiln is or how close the glass is to the elements, but my guess is that you are thermal shocking your glass, and leaving the lid open probably isn't helping the situation since the glass closer to the opening will be much cooler than the glass away from the opening.

Close the lid and try 250Â°/hr. Like all things, rate of heating is relative. 500Â°/hr is NOT slow.

Tony

Kim Bellis · Post by **Kim Bellis** » Tue Jun 17, 2003 12:21 pm

Thanks Tony, what you said makes perfect sense! The kiln is only around 13" in depth and by the time I put in the shelf and mold that brings my glass about 4" or 5" from the elements. I always thought 500 dph was slow - so I really appreciate that tidbit. I believe that will really help out with vases I have been trying to do!

I appreciate the help
Kim

Bert Weiss · Post by **Bert Weiss** » Tue Jun 17, 2003 12:36 pm

glassaddict wrote:Thanks Tony, what you said makes perfect sense! The kiln is only around 13" in depth and by the time I put in the shelf and mold that brings my glass about 4" or 5" from the elements. I always thought 500 dph was slow - so I really appreciate that tidbit. I believe that will really help out with vases I have been trying to do!

I appreciate the help
Kim

Kim

I think that your open lid is really the culprit. I'd slow down and close the lid. If that works, I'd start to see just how fast you can go with the lid closed.

Barbara Muth · Post by **Barbara Muth** » Tue Jun 17, 2003 3:33 pm

Kim, I don't have the shelf in my kiln when slumping. All you need are some kiln posts to elevate your slumping mold a bit so air circulates beneath it.

Barbara