That Kreem stuff is crap, it has flaked off in every tank I, or my freinds have used it in.
If the tank is metal, have it welded.
My experience with epoxy based sealers is they will work for a short time, but the extra vibrations of a motorcycle have them cracking and leaking again.
Don't use the Kreem stuff ever, its a good way to force you to buy a new gas tank.