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I recently tried to fuse onto a sheet of 1/8" with Youghegheny frits and powders. The sheet was about 8" x 16", but it ended up with several large bubbles in it,even though I thought I had good hold times, and not too fast of a ramp ( merely putting grit onto the glass - not fusing other pieces of glass together )
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I did the fusing on a kiln shelf, with no kiln paper ( which I find very hard on the lungs - if anyone has a good substitute, I'm all ears)

The ramp was:
300- 1120-10
500 -1560-10
9999-1020 -20
200-800-10

Too thin. Glass wants to be 1/4" thick at full fuse
I am assuming you are using float glass.

Yes, its 1/8" - the reason is I'd like to slump the finished sheet into a vase. I guess tack fusing it is the only option, rather than going to full fuse....or having to use a 1/4" piece.

I'm a bit confused here myself. I am assuming Rosanna wasn't right about there being any float glass involved.

You could work on top of 1/8" (dsb) compatible float glass. You must have PPG Carlisle or Fort Worth factories or out west some Vitro glasses are good. Then your slump schedule has to deal with the stiffer float glass on the bottom. Fuse with the tin side down, and never slump with the tin side up. Compressing the tin side will yield a satin finish wherever the glass is compressed, and glossy where it is not compressed. The reason you fuse tin side down is to end up with a smooth bottom. Air side down will end up gritty. In the testing I did, the tin side did not effect colors on the Yough.

To be certain, I want to fuse the colors into1/8" DS glass. Next step would be to slump it over a former.
At this time I'm still at the fusing stage, and want to get the colors into the ds sheet w/o big bubbles

The other info will certainly be helpful if I get a good sheet to slump

jerry keller wrote:To be certain, I want to fuse the colors into1/8" DS glass. Next step would be to slump it over a former.
At this time I'm still at the fusing stage, and want to get the colors into the ds sheet w/o big bubbles

The other info will certainly be helpful if I get a good sheet to slump

Is there some reason not to fire them all together?

In my opinion your ramp was too fast and too hot.

jerry keller wrote:I did the fusing on a kiln shelf, with no kiln paper ( which I find very hard on the lungs - if anyone has a good substitute, I'm all ears)

You may want to try Spectrum's Papyros, if you haven't already. It holds together rather than turning to all powder like Thinfire does. It's much easier to clean up -- Spectrum shows using a spatula to fold it and toss in the garbage, which I find works well.

Many people get multiple firings out of it. I use it once, and toss it. I don't care about the multiple use, but I LOVE the easier cleanup.

Dana W.

jerry.....it would be much easier to determine a fix if you added a picture. Other than that ramp, in my opinion, being much too fast......if the single sheet of glass was not completely covered with frits you would blow holes from not enough volume. I do not think firing on theshelf was the problem.

Probably not a problem with ramping too fast; it's simply difficult to full-flat-fuse powder/frit into a thin sheet without making bubbles or holes, especially if you're using harder colors.

I'd consider using enamels/glass paints that won't require a full fuse to color the glass. You'd get the color you want without the potentially hole-making flat fuse.

The other thing to think about, though, is how thin you really want your vase. If the sheet stretches at all you may find that 1/8 inch is too thin. I'm making goblet bowls right now, dropping a 4-inch diameter circle of glass about 3 inches, and a 2-layer blank is 'way too thin. Doing the math:

4-inch diameter piece of glass, .25 inches high: 3.14cu in. volume

3.14 cu in. volume stretched to 7 inches in diameter: .08 inches thick, i.e., not enough

So...it's possible that you may want more than a single layer of glass in your blank anyway.