Secondary Drying and Chipping Stage
The secondary drying and chipping stage is when a small space heater can be used to warm the glass up to around 52C (125 F). Do not point the heater directly at the glass. Keep it at least one metre away from the glass. You don't want to cause the glass to get too hot and crack.
This indirect heat will cause a rapid evaporation leading to curling of the glue and the chipping of the glass surface. The glass is under extreme stress at this point and should not be handled unless absolutely necessary. On sunny days the glass can be set in direct sunlight. This is the easiest way to get the glue to chip the glass.
The chips of glue can pop off and travel some distance, so take appropriate precautions, i.e. safety glasses, gloves, aprons. You might want to place a cloth over the surface.
After all the glass is chipped, some glue may still be left on the glass. The glue is water soluble, so you can soak the glass with warm water and scrape off the softened glue. Be careful of the extremely sharp shards that are now concealed in the water.
The glue and glass shards left from the chipping process can create a big problem if not cleaned up. Because the glue is an animal by-product, cats and dogs love to eat this stuff. This can cause your pet extreme harm and even death! Dispose of the waste carefully.