I have been printing with PETG on glass for a little while now, and have gone through almost an entire roll. Yesterday I had my first print stick so hard that it delaminated the glass :(. I stopped using hairspray as it made the prints not stick at all, and printing bare glass was just fine. But something about yesterdays print made the glass give up. Is this how PETG + Glass normally fails? Works perfectly for years, and then suddenly fails?
I used to do tape, but i really like the smooth finish that bare glass gives. Glue stick gave me bed adhesion issues, and i cant easily remove the glass bed.
I think the glass delaminated while it was cooling normally, not when i was prying it off.
You might look into a smooth build plate. It can take the damage and just be replaced.