Originally Posted by
awerby
I don't think that graphite powder plus epoxy will be any stronger than epoxy and any other kind of powder. The physical structure of the granite, optimally graded from coarse to fine with a minimum of glue holding it together, is what gives epoxy-granite its strength. Carbon fiber is different from graphite powder - due to its linear structure, it does add tensile strength to materials it's mixed with. But don't take my word for it - mix up some test batches of graphite and epoxy and granite and epoxy, cast them into bar shapes, and then try breaking them with compressive forces. See which one breaks easier.