Keeping glass in contact with mold crystal clear

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deandv
Posts: 2
Joined: Thu Apr 25, 2024 10:35 am

Keeping glass in contact with mold crystal clear

Post by deandv »

Hi all, dean here, product designer/maker totally new to glass forming.

I'm slump forming 3/16" float glass over a graphite mold, and I'd like the result to be as clear as the original glass. The glass comes out of the oven though with a hazy, somewhat rough, surface where it was supported by, or even near, the mold.
  • the mold is graphite, new, pretty darned smooth
  • no kiln wash or paper
  • 300°/hr to 1400°F, hold 40 minutes; AFAP to 900°F, hold 60 minutes; 100°/hr to 700°F; oven off.
Is it even possible to have a perfectly clear final surface where the glass contacts the mold? Any tips on how I can get closer to that ideal?

thanks!
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Kiln and formed.jpg
graphite mold.jpg
jolly
Posts: 64
Joined: Thu Jan 08, 2004 7:44 pm
Location: Port Townsend, WA

Re: Keeping glass in contact with mold crystal clear

Post by jolly »

Only saw this now. I wouldn't use graphite in a kiln. Yes, you can shape glass without it taking on the texture of the mold. About 1200 degrees F, it should not take on the texture since it is float glass.
There is more to life than increasing its speed.-Mahatma Gandhi
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