reversing a bowl/re slumping to invert bowl?

[Leslie Ihde]

I slumped a shallow bowl using BE glass about 16" in diameter, 1 1/2" deep. Now I want to change that. I sand blasted the inside and want to reslump so that the sandblasted surface will be on the outside. See and problem with that? I think I'll use a wok shape, a steel mold. Thanks in advance, Leslie

[Bob]

Hi Leslie,

I guess it would work all in one slump but I wonder if the slight stretching that occurred duringh the initial slmp might cause an edge to develop a ripple or crease. If the piece was a real keeper then I would go a conservative route and place the bowl on a kiln shelf and slump it back to a flat shape.... anneal and cool to room temp. Then it probably should be resandblasted prior to the final slump. Just guessing though.

Hope it works.

Cheers,

Bob

[Leslie Ihde]

Hi Bob in Canada.
It must be cold there, it's been a terrible winter here in upstate NY.

I wondered it I should do 2 slumps. But I worried about devit- it's already been fired 2x and devit seems to start to get excited after 3 firings. Not sure What I'll do- maybe a super slow single slump. Thanks for your help.

Leslie

[Bob]

Hi Bob in Canada.
It must be cold there, it's been a terrible winter here in upstate NY.

I wondered it I should do 2 slumps. But I worried about devit- it's already been fired 2x and devit seems to start to get excited after 3 firings. Not sure What I'll do- maybe a super slow single slump. Thanks for your help.

Leslie

Hi Leslie,

If you are slumping and keep the temperature low ( just enough for the glas to bend ) then devitrification will not be a problem. Devit starts at about 1375F for Bullseye. You should be able to slump your piece at 1150F

Cheers

Bob

[Leslie Ihde]

I will try at 1150. It's good to know where devit starts. Leslie