Fire Polishing - WarmGlass.com

Fire Polishing

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Greg Rawls
Posts: 147
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Location: Charleston, SC
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Fire Polishing

Postby Greg Rawls » Mon Jan 05, 2015 11:42 pm

I have finished a piece - 1/2" thick, 16" diameter. Bullseye glass. During cold working the piece I scratched it pretty bad so I need to fire polish. I want the piece shiny vs matte and I don't want to cold work it again! It is ready for slump. Suggestions? I'm thinking that I sandblast it then fire:

180 > 1000 > 20 min
300 > 1175 > 30 min
500 > 1275 > 5 min
9999 > 900 > 120 min
100 > 800 > 0 min
180 > room temp and off

What do you think??????
Greg

charlie
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Joined: Mon Mar 10, 2003 3:08 pm

Re: Fire Polishing

Postby charlie » Mon Jan 05, 2015 11:46 pm

i'm not sure 5 min at 1275 will firepolish. it won't in my kiln. i'd get a light matte surface.

you should look in at 1275, and see if it's shiny enough for you. if not, just increase the time.

Warren Weiss
Posts: 137
Joined: Thu Mar 13, 2003 8:06 pm
Location: Richmond, VA

Re: Fire Polishing

Postby Warren Weiss » Tue Jan 06, 2015 2:13 am

Greg,
I wouldn't exceed 150F/h in the initial ramp. Don't see a need for a hold at 1175. Like Charlie, not sure 1275 will do it from a sandblast finish. I'd go to 1300 for up to 10 min. Eyeball to decide. Hold at 900 for 2 1/2 hours and drop to 750 at 90 d/hr. Off at 750. Be sure to dam it as you did in the original firing.

Warren

Greg Rawls
Posts: 147
Joined: Sun Mar 09, 2003 8:11 pm
Location: Charleston, SC
Contact:

Re: Fire Polishing

Postby Greg Rawls » Tue Jan 06, 2015 9:27 am

The hold at 1175 is to complete the slump. I'm trying to avoid damning because that means I have to cold work again. Thanks for the good advice!

Warren Weiss wrote:Greg,
I wouldn't exceed 150F/h in the initial ramp. Don't see a need for a hold at 1175. Like Charlie, not sure 1275 will do it from a sandblast finish. I'd go to 1300 for up to 10 min. Eyeball to decide. Hold at 900 for 2 1/2 hours and drop to 750 at 90 d/hr. Off at 750. Be sure to dam it as you did in the original firing.

Warren
Greg

Warren Weiss
Posts: 137
Joined: Thu Mar 13, 2003 8:06 pm
Location: Richmond, VA

Re: Fire Polishing

Postby Warren Weiss » Tue Jan 06, 2015 1:49 pm

Greg,
The slump will complete before you reach 1300 without a hold at 1175. Didn't realize that you were firing in a slump mold so damming won't be necessary unless you exceed 1300.

Warren


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