Last days, I discovered that old grinding belts are prone to break by the scarf joint. This is an annoying but solvable issue.
Grinding belts have an expiration date
Yes. Grinding belts have an expiration date because the glue used in the scarf joint do not lasts forever. This was surprising for me! I discovered the hard way. Some days ago, I needed to sand some boards but I couln’t achieve it: all the (new) grinding belts I tested were splitted cleanly by the scarf after one or two seconds of using it on the grinder.
Annoyed by this, I begun a search on the net that ended with that result: grinding belts have a finite shelf life. I have a set of them unglued and a bunch that will unglue for sure: can them be glued again?
Searching a glue
Which kind of glue can we use to glue again the belts? It should support an important strength and, when working hard, also a significant temperature. Indeed, it cannot be rigid once cured: the belt turns through a short radius roller and the join must be flexible enough.
After some test with other glues, I discovered that there are flexible cyanocrylate glue —they contain gum dust mixed. This was the glue that offered to me the best results. I choosed exactly Loxeal 74 and a made to size press make easy the glueing. The result was outstanding: