Tin side tester Float glass

Stained glass painting on float glass:

The metal oxides in the stained glass paints can form an undesirable bond with the tin residue when burned. (you get a different color, the paint doesn't stick, etc.)
After you have determined what the tin side is, you will start painting on the other side.

Fusing with float glass:

"Dividfrication" or in Dutch "deglazing" looks like matte spots in the glass and we don't want those. If you fuse with float and place the tin side up, the tin can burn or oxidize. To prevent this, you should always place the tin side down.

Installing patinated stained glass between double glazing:

After patinating a stained glass panel, some patina may remain between the glass and the lead. If this stained glass panel is built in and placed in the sun, the remaining patina will evaporate and settle on the tin residue, the tin will then immediately oxidize black and you will then have dirty spots/haze on the inside of the float glass.
To prevent this, first allow the stained glass panels to evaporate for a few days/weeks before installing them. Then test the tin side and place it to the outside.

Instructions Tin side tester float glass:

• You can only see it in a dark room.
• Slide the fluorescent beam over the glass, the tin side lights up as a white haze (see photos).
• The fluorescent light only comes on for three quarters.
• If you have a good quality float you will not see the tin side, so the lamp is not broken.