How many parts can I mold before having to reapply another?

Depends on too many variables to be specific, but some simple guidelines for maximizing the number releases are as follows. 1) The solvent-based products are generally more abrasion resistant when compared with the water-based materials. 2) Both solvent and water based release agents significantly benefit from being applied correctly, on top of a recommended mold sealer. Also if the mold is not thoroughly cleaned before it is sealed, the number of pulls will be dramatically reduced. 3) It is always recommended that you run a small trial to establish the maximum number of parts you can mold from your individual mold and resin combination, before the release starts to become difficult. Zyvax strongly recommend that you then allow a factor of safety for production molding of about 20%. So for example if your test indicates that de-molding becomes difficult at 50 pulls, reapply release agent after about every 40 moldings in production.