Thanks

Where you will come unstuck (pun intended) with 2k coatings is if the tooling gelcoat softens the coating that it is applied to. Once the coating has softened, the film of chemical release agent is compromised and you will get sticks. This is just as likely to happen with a 2k topcoat as it is a 2k primer, it simply depends on the compatibility of the paint and the gelcoat and how well cured the coating is. This is why you should always test the products that you intend to use together - not all coatings are made equal. Polyurethanes tend to have good chemical resistance in general, but some are better than others. A good way to test is to polish up your coating to the standard that you desire, and then wipe it with a powerful solvent like acetone or MEK. If the surface dulls, then it's because the solvent softened the coating and I would not recommend proceeding with the tooling gelcoat. If the solvent flashes off the surface without affecting the finish, then you can be reasonably confident that the gelcoat won't attack it. Personally if I am using a new product for the first time then I always like to do a little test with the gelcoat that I'm using as well, just for piece of mind.