Dennis Brady is a master glass artisan who specializes in float glass. Importantly, he is the creative force behind “Glass Campus” where the motto is: “When we all share, we all gain.” This website is an incredible resource of tutorials, videos, information sheets, and new ideas.
Float glass has properties that make it superior to art glass. Float has the advantages of low cost, wide availability, clarity and hardness. The iron in the glass strengthens it and gives it the green tint. There is an ultra-clear float glass that uses rare earth elements. Regardless of continual changes in the art glass industry, you can be sure that float glass is easy to get, affordable, and excellent for glass art.
Production of float glass began in the 1950’s. “Floating” glass across a tin bath allowed for consistent quality and high production speed. Of course, one side of the glass is in contact with the tin and so that can affect how you use the glass. It used to be that float glass sheets were only reliably compatible for fusing within the same sheet. Nowadays, currently-produced float glass is almost all reliably compatible. Older float glass has more problems, less compatibility. Also worth noting: production speeds are faster these days and so the tin layer is thinner.
If you’re fusing with float glass, you want the topmost layer to be tin-side up to reduce the chance of devitrification. Within the fused piece, the order doesn’t matter: air to air, air to tin, tin to tin – all is good. An easy method to check compatibility of your planned fuse project (this works for all types of glass): fuse test pieces together, let it cool, wrap the test piece in a dry cloth and put it in a freezer. Let it fully freeze. Take it out of the freezer, unwrap it and allow it to thaw. If it cracks while thawing then it’s not compatible.
If you’re painting with float glass, you need to know which side is the tin side. Some paints don’t react well with the tin side (transparent paints), copper red needs the tin side, silver stain is darker when fired on the tin side.
We even use 6mm float glass as a kiln shelf and get a very smooth bottom surface on fuse projects. The tack fuse and full fuse temperatures of art glass and float glass are sufficiently different.
I invite everyone to take a look at the Glass Campus website. Any questions? Feel free to contact me. I’m a huge believer in sharing information. No secrets. Definitely: when we all share, we all gain.