Finished thick piece, but now need layer at bottom

[Bonnie Rubinstein]

I am creating a sink, fused the glass to 7/16”, and now realize I need to add another layer, a ST layer of Firelight White to the bottom. I know that by putting the thick glass on top of the white at bottom, I will create bubbles. But by flipping it, topping it with the white(which I will score to mitigate bubbles here,) firing it, I will then have to flip and fire polish that later. (It has a beautiful finish now, that I am afraid to ruin). Plus, I have already fired this 3 times. so this will be #4, and fire polish #5.

So, should I attempt to just put the thick piece on top of the white, and fuse and pray?
Thanks for your guidance!
Bonnie

[DonMcClennen]

I would suggest you put the thick piece on top of the white(with chads!!) then proceed with a verrrry slow firing up (perhaps 100F dph) with a 1 hr pause at 1150F and a bubble squeeze of 30F dph from 1150F to 1300F then 300F dph to fuse temp. Also really slow thru anneal zone with long anneal soak on way down.
Good luck, Don

[Bonnie Rubinstein]

Thanks, Don; I think this is best.
Are you referring to small frit (chads), and place them between the white and the thick glass above it?

[DonMcClennen]

Tiny clear (or in your case white) frit sized chip. Place only 2 or 3 chips at very edge of white so top piece will sag or slump down in middle pushing air outwards before fusing takes place. I sometimes only use one chip at very edge so the top piece sits at slight angle at setup. Slow bubble sqeeze I suggested is very important here.

[Bonnie Rubinstein]

Thank you.