Multiple firing annealing process

[The.dragonfly]

I have a kiln fired project that I am ramping up to build.

‘When you have two full fuse firings and a fire polish firing, when do you anneal the piece’

I am firing a detailed three layer casting that varies from 9mm thick to 25mm thick. I am planning to use the annealing thick slab schedule for 50mm thick glass. This schedule is ~47 hours long. I am hoping to get an answer from someone with experience on castings with multiple thicknesses.

I cast a piece a while back with similar technique, using annealing cycle on both full fuse cycles but I used a 25mm slab annealing cycle on my 6-19mm piece. Still got a nice crack. I blame the crack on the rigid inlays, not necessarily the firing cycle.

Castalot mold mix, all bullseye sheet glass and frit (fuse 90coe compatible)

[The.dragonfly]

This is the picture of my last piece. 6-19mm thick

[mattt]

Hi The Dragonfly.
In answer to your question, you need to anneal your glass EVERY time you cool it down from above 482C to below it. Every time it goes from being fluid to being solid again, it needs to be annealed.

You can get away without annealing ONLY if
a) you're doing domething tiny & / or thin, e.g. if all that you're making in your kiln is frit balls, or
b) you don't mind if what's in the kiln breaks!

Hope this answer's not too late....
Mattt