Sodium Silicate has a long track record. It’s non toxic, and when heated it dries and forms SiO2, or glass. Tough and long lasting.Why do you object sucking in JB Weld, but do approve of using Waterglass ?
No pun intended, serious question
For me a mixture of hardwood (oak) ash and water always works fine.
I’d rather deal with that than fiberglass particles and the off gassing of epoxy…