clear and gel coats

ive noticed that the west sytem epoxy im using sticks to the cheap poly resin i use really bad. but in the opposite it doesnt hold at all. i know i need a tie coat for either way. what should i use. i have west 105 resin would i need a tie coat for the clear gel coats that are sold on this site? if so any pointers? thanks

You can layup with epoxy on top of cured poly but you can’t do the opposite. Epoxy will bond to cured poly but poly will not bond to cured epoxy.

would you recomend gel coating epoxy over polyester? if so i think it might be cheaper to make cosmetic parts out of poly and then gel coat with epoxy and then

If it’s a molded part, just use clear gel coat in the mold prior to a polyester layup. It should come out with a nice clear finish on it if you’ve done the prep work.

Gel coat is polyester based and will work best with polyester resins.