Screen Melts

[Brandi K]

I have recently had 4 screen melts crack. Two had one clean crack and the other two completely shattered. I am trying to make a 12 inch round, 3/4 inch thick, using spectrum. I am melting into a stainless steel ring lined with fiber paper. My schedule is:
800 to 1600 hold 90min
9999 to 1475 hold 30 min
9999 to 960 hold 60 min
200 to 750 hold 0
50 to 300 hold 0
Please any suggestions before I was anymore time and money.
Thanks in advance
Brandi

[Brock]

Anneal for a MINIMUM of one hour per 1/4" of thickness.
Look up Clearwater Glass and compare his schedule.

[S.TImmerman]

Mr Immerman is so generous to post these to help people: http://www.clearwaterglass.com/Tutorials/MeshMelt.html

[Sharol]

Hi Brandi,

You might want to check out S96 firing schedule for thick projects: http://www.system96.com/Pages/ThickFiringGuideF.html
I think you need to do some work on the annealing and cooling portions of your schedule. 3/4" is a pretty thick slab and you'll need to slow your schedule down quite a bit.

Best of luck with this!

Sharol

[DonMcClennen]

Why are you using 960F to anneal??? it has been listed at 950F (according to "96" documents for several years)

[Laurie Spray]

yours ours
9999 to 960 hold 60 min 9999 to 950 hold 3 hours
200 to 750 hold 0 100 to 850 hold 1 hour
50 to 300 hold 0 100 to 750 hold 1 hour
100 to 600 no hold and off - let cool totally to room temp before opening


This is works for us.

[Laurie Spray]

sorry that came in so hard to read - this is better
9999 to 950 hold 3 hours
100 to 850 hold 1 hour
100 to 750 hold 1 hour
100 to 600 no hold and off - let cool totally to room temp before opening

[Cheryl]

Don't hesitate to re-use your shattered pieces in new melts/pieces. That's part of the joy of fusing!

[Stephen Richard]

I agree with Laurie on the three hour soak at 950F.
However I disagree on the soaks during the annealing cool. The principle is to reduce the temperature gradually enough that the whole of the glass is within a few (+/- 5 deg) throughout. This in my view is better achieved by a slow consistent cooling rather than a cool followed by a soak. I am not sure that what will happen on a quicker cool will be cured by a soak.
So from 950F I suggest a rate of 45F/hr to 850F, on soak; then 80F/hr to 650F, no soak; followed by 270F/hr to room temp[you have no idea how hard it was to put this into F rather than C].

I am also wary of using the old melt pieces, especially if they are hot colours, as they tend to change characteristics after high temperature firings. But only testing will prove.

[Laurie Spray]

Maybe the reason that this schedule works for us is that my kiln cools very slowly. For instance last night i had a look and it was 800 at 11 pm and this morning at 8 am it is 450. In a fast cooling kiln i would agree with your caution.
I should have added the footnote that every kiln fires differently so you have to get to know your own kiln. I have 6 and they all fire quite differently! Thanks Stephen for reminding me........ maybe that should be part of a signature line?