i had that problem with the first holster i made turns out i used too much resolene a little too quickly the last 2 holsters i've done i decided trying to mix the resolene 50/50 with water and i just brushed it on with a wool dauber and it worked great no cracking yet. word of caution though if youre gonna put on more than one good coat you do want to let it dry in between applications i usually let it dry over night before i put another coat on