|PVA (Polyvinyl Alcohol) should be used with mold release wax to aid in the release of parts form a mold. It should be applied in three thin mist coats over nonpourous, waxed mold surfaces. After the final wax coat has dried, begin by spraying a light tack coat of PVA. Typically, within 5 minutes the final heavier coats can be added. The PVA dries to form a smooth, glassy film. After part release, the residual film can be removed with water. We recommend using an inexpensive automotive siphon spray gun and 70-90 psi for application, although airbrushes will work on hobby size projects. PVA can also be sprayed over any polyester repair to provide an airless tack-free cure. For use with epoxies.|
I have experience with moldless composite construction (laying up on foam), but have never built larger parts on a tool requiring the part to release. I did some testing using Stoner release wax alone, and the Stoner wax with this PVA product applied over the wax. I am building a cowl and using both the wax and the PVA, the release has been excellent. I could be wrong, but I attribute the release to the PVA. I applied it with a foam brush as I dont have a spray set handy. I recommend two coats of the PVA at least as it tended to bead up on the buffed waxed surface.
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