4-layer full fuse firing question

[Carla Sarvis]

hello: original work is 2 layers aprx. 15.5"x6" and is already flat fired. Desire to increase presence of work with an aprx. 17"x7" back panel, ,which I haven't fired yet but will. A single fired layer for back panel will not fit properly in the custom made stand, so the back panel needs to be 2 layers. Please advise the proper program to full fuse 2 previously fired works into a 4-layer piece. The back panel visually acts to frame the smaller panel which does not reach the edges. Help by Thursday evening would be most appreciated. Use Bullseye glass/Skutt coffin kiln. Thank you.

[Stephen Richard]

I would fire separately and use glue to stick them together

[Terry Curtis]

I've done this successfully in 2 steps. First was to full fuse the back piece. Second was to put the two pieces together and do a tack fuse. I was very conservative in the firing schedule to prevent thermal shock. Also, remember to anneal for the thickness of the piece.

[Laurie Spray]

i would fire it in one more firing......2 layers background....prefired top of 2 layers. I would fire 50 degrees an hour>800 no hold
250 hr>1200 hold 60 min
50 hr > 1250 hold 60 min
350 hr to your top temp....maybe 1460 depending on the look you want
9999 to 1200. ......i add this so it stays flat. Hold here maybe 30 min?
(This temp is just off the topmof my head.......i use it with long flat panels)
50 hr to anneal. Anneal for at least 3 hours and fire down very slowly.

Anyway......this would work fine in my top firing genesis.

[Morganica]

To be a bit more specific: Use the Bullseye schedules for annealing thick glass, found on their website. Your piece will be close to a half-inch thick.

If you're flat-fusing, the half-inch schedule is probably sufficient. If you want to tack-fuse (to keep the angles sharp and have obvious separation between the background and the fused piece), you'll need to use the schedule for a full inch, assuming all components are flat.

[Laurie Spray]

Thanks Morganica......i wrote that on the fly......

[Jerrwel]

i would fire it in one more firing......2 layers background....prefired top of 2 layers. I would fire 50 degrees an hour>800 no hold
250 hr>1200 hold 60 min
50 hr > 1250 hold 60 min
350 hr to your top temp....maybe 1460 depending on the look you want
9999 to 1200. ......i add this so it stays flat. Hold here maybe 30 min?
(This temp is just off the topmof my head.......i use it with long flat panels)
50 hr to anneal. Anneal for at least 3 hours and fire down very slowly.

Anyway......this would work fine in my top firing genesis.

(1) I'd note that the back portion is larger than the existing 2 layer front piece so I'd do as suggested here except I'd only take the firing to a low tack fuse (not a full fuse i.e. 1460) in order to tack the back glass pieces together and to fuse them to the front piece simultaneously and with the potential of having an interesting texture on the sides of the back piece. If the back two layers need to be fully fused, this process would take two firings.

(2) Another thought would be to construct a 2-level mold and fire face-side-down with the existing piece in a mold or dam and the larger back pieces in a larger mold or dam on top of the existing piece's mold and then fired to full or tack fuse noting that the face might then need to be cold worked. That said (and maybe not too clearly), process (1) would be my choice.

If time allows, I'd definately be doing a test fire.