Glass fibers will add "something".
Posted by: g2d on Nov-01-12 11:25 PM (EST)
And mixing in some Kevlar strands will reduce the chance of chipping pieces out of your edging.
Epoxy is a wonderful binder, but by itself, it is actually less sturdy than a lot of plastics, such as Nylon, Lexan.
But epoxy binds strongly to fibers, fillers, and surfaces of other materials. That's something other plastics often don't do. It is the combination of epoxy with suitable reinforcing fibers that can make a paddle edge strong.