drilling a tank

[sphelps]

Originally Posted by Snaz

To ensure the glass is not tempered view it with polarizing sun glasses. If it is tempered, a pattern will appear, no pattern and it is safe to drill.

You'll need another polarized filter on the other side of the glass to see the pattern. For practice try the side and rear windows of a car for tempered and the windshield for untempered.

I've drilled a few tanks half full, but I wouldn't recommend it. Much better in the long run to start over.