Depends what you mean by cracked edges... if you mean it in the conventional sense, i.e. a hairline crack in the metal edge, then gluing it isn't going to do anything as the edge bends and it will just pull apart as it slightly expands when bent.
If you mean sidewall cracks, or sections of edge coming out, then a good epoxy is the way to go... but if you're not mixing it right or letting it cure properly then that's half your problem.