We use glass (on platens) on every grinder in the shop.
Borosilicate or fireplace glass has multiple brand names. Fireplace glass handles heat expansion better than “regular” glass. Proprietary versions are used in cooking glass pans, cups, etc. It is often called ceram, ceramic glass, pyro ceram, etc.
advantages: grinds significantly cooler due to lower friction, easy to install and replace, wears longer than hardened steel platens.
Disadvantages: it will generate static electricity in low humidity, it can crack or might even come loose if improperly installed.
The cost of the glass is slightly more than a hardened steel platen but it last longer. Glass will wear as does steel and will need to be replaced.
If you flat grind you need a dead flat platen or you will struggle to get an even grind line. I can not emphasize this enough. Make sure you platen is dead flat and does not have grooves or low spots.
We use and recommend JBWeld to install due to it’s higher heat rating. I keep a can of laundry anti-static spray by the grinders to knock down any static shocks if the humidity is low. I spray all around the belt and machine but this just doesn’t happen that often.
Regular and safety glass will crack from heat generated by grinding. I know this because I’ve tried both in the past. I can’t recommend this enough as a grinder mod.
