hello, i glassed a 5’8 shortboard and when i put the first hot coat on it was very thin, so i decided to put on a second hot coat over the first one so that it would be stronger, i used sanding resin on both hot coats. when i sanded it afterwards, i sanded through the second hot coat in certain spots, now when i sand near the spots that are sanded through to the first hot coat layer it starts cracking around the spots and the second layer keeps cracking more and more. it seems as if the two layers didnt bond to eachother. now i have a sanded board with certain spots that are cracking and chipping off (only the top hot coat layer) and certain spots that are fine. what do i do? if i put more resin over the spots that are cracking, it will do the same thing when i go to sand it. any advice?