A client visited us last month and we were discussing painting on float glass. Peter mentioned that it was possible to check for the tin side of float glass with a drop of water. It’s true! You don’t have to use a UV lamp.
Float glass (normal window glass) is made by floating the glass on top of a molten tin bath. The side of the glass in contact with the tin bath picks up residuals from the tin and this will have an effect on your silver stains and may have an effect on your other glass paints. Best to check the glass before painting and plan accordingly.
How to check the tin side with a drop of water?
- Clean your glass thoroughly, both sides.
- Drop a single drop of water gently onto your float glass from a height of approximately 2-3 cm (1-1.5 inches). Do not touch the glass while dropping the water.
- See how the water drop spreads out – or doesn’t.
- Repeat on the other side of the glass and compare the results.
When the water drop spreads out, there’s no film from the tin bath and it’s the non-tin side. If the water drop remains tight on the glass, that’s the tin side. PELI is now teaching this method in all our glass painting workshops!
Water drop: a ball and small?
The film is thin, that’s the side with tin!