I had a bong that was shattered by an ashtray and glued it together with J-B Weld it is water proof and i hear its drinking water safe...
it takes 24 hours to dry, doesn't expand, you can break glass before the "weld" will break and it looks somewhat clean. if you can fit the glass together it wont even look that bad.(i think it would look better if i got another try)

Heres some pictures
Missing Glass Hole Patch
Missing Glass Hole Patch 2
Best looking patch
Best looking patch 2
fred666777 Reviewed by fred666777 on . A Bong Fix. I had a bong that was shattered by an ashtray and glued it together with J-B Weld it is water proof and i hear its drinking water safe... it takes 24 hours to dry, doesn't expand, you can break glass before the "weld" will break and it looks somewhat clean. if you can fit the glass together it wont even look that bad.(i think it would look better if i got another try) Heres some pictures Missing Glass Hole Patch Missing Glass Hole Patch 2 Best looking patch Best looking patch 2 Rating: 5