Posted by Mike Jackson on February 17, 2004
Danny mentioned the process of taking a warm piece of glass with glue on it outside to in effect "shock" the glass. That works, at least to some extent, but you do have to use it with discretion. I normally don't try that unless I have just about given up on a few stubborn areas. I figure it will either work beautifully, or I will end up cleaning off the glue and then reapplying the glue in the stubborn areas.
The rapid change in temperature causes the surface of the glass and glue to change, usually causing some violent chipping for a short period of time. After that, however, you must take the piece back inside. After it has been exposed to the cold, the glue will often absorb moisture and eventually it becomes non-responsive and will not chip again. You might get two warmings and two shocks, but after that you will have to reglue the unchipped areas. Overall, I usually just prefer to leave off the cold shock and let the glue do its job.
Mike Jackson
Denver Chapter of the Letterheads