I've limited myself to epoxy-only use over the last few years, even for gelcoats and asking around a bit, all other Frekote users have done the same. Your last remark is - as always - solid advise anyone should follow. It saved my ass last time at least ;-)Watch out, though, it's not a superpower. I have one or two molds where, for whatever reason, Freekote just doesn't work, even when I apply the FMS sealer and then the 700. My vinylester primer still sticks to those molds right through the Freekote products, and I have to scrap the part and carefully scrape and sand out the primer and try again. For those few molds, several coats of carefully-applied was is the only thing that works. Bottom line, I'd do a quick test pull on each mold before doing a full size part.