Float glass - tin side doesn't show under UV

[Sandy Pendleton]

I am making some float glass bowls for a charity project. I have been cutting up any float glass I can find. I have a UV lamp, and most of the time can tell which is the tin side using the lamp. I recently cut up a clear table top and noticed no difference from one side of the glass to the other under the UV lamp. I am concerned that I have something unusual and I don't want to have it blow up in my kiln taking it to full fuse. Any help is appreciated.
Thanks,
Sandy

[Brad Walker]

It was probably drawn sheet glass, rather than float glass. Drawn sheets don't have a tin side. The drawn sheet process (also called the Fourcault process) was replaced by the Pilkington process, which uses molten tin.

You can heat it like you would any other glass.

[Morganica]

But in any case it's not going to blow up in your kiln. The surface and sintering qualities change depending on whether you use the tin side or the top side in float glass, but they do actually work together. One of my favorite float usages is combining tempered crumbles with larger shards in a mosaic pattern that's subsequently pressed into a mold, and it's virtually impossible NOT to combine tin/non-tin sides. I've never had a problem with them.

Glass made with the Fourcault process will be a bit wavery, can have more inclusions (either stones or little bubbles) and just isn't quite as flat and smooth as Pilkington process (float) glass. It's still very nice, though, and the fact that there's no tin side *can* give it a bit more brilliance than float in fused applications. Interestingly, when I've purchased it, it's been more expensive than float.

[Sandy Pendleton]

Thank you both for the quick answer. I'll go on about my merry way.
Sandy