Hoping to fix the crack I just saw

[Havi]

Hello every body, and very happy holidays to all of you.

I tried to fuse together a mesh melt which I recently made to a strip fused sheet
I made.
The strip sheet has an uneven textured face, which I like a lot, therefore I put the melt under the sheet, and also covered the sheet with a blanket, in order to have lower temp. at the top of the piece and higher temp. at the bottom. This is fired in a deep kiln , i.e. there are electrical elements under the piece, also I use dysson shelf which allows the air at the bottom circulate a lot.

I opened the kiln at 125.6 F , and saw a crack going from the melt underneath towards outside the piece. I do not know if it is a compatibility problem or an annealing problem. But the crack is in the upper sheet of glass, not in the melt itself.
It might be compatibility, as in the melt I have BE 1442 - Neo Lavender shift. This color, [which I love] gave me already problems in the past, where is was clearly compatibility problem . At that time, when I made the melt, I fired at 1700F, which is much higher that what I did now.

Anyhow, I decided to refire , hoping to fix the crack. A much more conservative schedule of course.
Considering that it is now Thursday night in Israel, I think I wo'nt be seeing the piece only on Saturday morning. A long firing.

Has anybody any comment on this?
Have you incurred such a problem in the past? or similar?

I apologize for not writing the whole schedule, as it is in Centigrade, and I am too tired to translate it to Fahrenheit.

Many thanks,
Havi

[Havi]

JUST AN UPDATE

After I tried second time to refire under improved conditions, and the piece broke even more -
From the cracks and breaks I saw, I realized that there was not enough heat on this piece, as simple as that. You could see it, that edges did not round, and other signs.

I decided to give it another try. ( a third one)

This time I fired regularly. Conservative, slow schedule, with a long soak at 770 , this is a trick I learnt somewhere in a class, and proved to be very helpful sometimes.
The piece is now at the annealing process.
But it looks healed.


I am very happy about it.

Havi

[Havi]

PROBLEM SOLVED .

PLEASE READ MY NEXT PROBLEM [IF YOU WANT, OF COURSE]



thanks for everything,
Havi

[Stephen Richard]

Havi,
Pleas post you're schedules in Celsius. There is a conversion too at the top of the page that every one can use. I do all the Tim to get these pesky F temperatures into something I can understand

[Havi]

Steve,
Thanks for responding.
There is no point in sending the schedule, even though I work with Celsius, as everybody else in Israel.
I am sure it WAS heat problem, and I solved it!
I raised the temp. and this made the difference. Only that now I have a devit problem - which I'm hoping I'll solve also
Went like [from my memory, not my notes]
45 dph - 540 hold 10-15 min
150 dph 600 hold 10 min.
150 - 770 - 40
333 - 830 - - - - - - proved unnecessary, as it was completely red at 770. let it go as high as 808, then conservative annealing.


Havi