refusing a bowl

[BonnieF]

I think I know the answer to my question, but want to confirm it from you experts out there!

I removed a bowl too soon out of the kiln from a slump firing in to a clay mold...and the glass bowl cracked.

I'd like to refuse it back into the slump mold. My question is how much higher should I go temperature wise than the last firing. Here is the schedule I used to slump it:

300 1310 .10
Full 960 .45
60 825 .01

Any help would be great. I'm thinking if I took it to 1350 in the same schedule it would fuse together. I don't mind having any hairline cracks in appearance.

Bonnie

[Morganica]

Think about the difference between fusing and slumping, though: Fusing happens AFTER slumping. That is, it takes more heat to fuse glass, and certainly to fuse it so that broken pieces heal seamlessly. By the time the pieces fuse together, even if you leave hairline cracks, the glass is liable to be so soft it's sliding to the bottom of the mold.

Best thing, usually, is to fuse flat to repair and then re-slump.

[BonnieF]

FYI. I refired the bowl in the mold and went up 40 degrees. Worked like a charm.

[DonMcClennen]

I doubt it!

[BonnieF]

I'm serious, it really did work. I don't have a small enough photo to post or I would. Of course there is a crack line but I don't mind that as it's a prototype for something else.

[Laurie Spray]

It may look ok at the moment but it is only tacked together at 1350 and will probably crack eventually.

[Stephen Richard]

Your slumping temperature is high. 1200 to 1250 F should be enough.