Can PVA be used on a wood or plaster mold without sealing mold first?
No, both wood and plaster molds must be sealed prior to application of PVA. Primer-sealers and lacquers intended for composites use generally produce the best surfaces. Mold release wax should also be applied to wood molds prior to use of water-soluble PVA coatings such as Partall® Coverall Film or Partall® Film #10 to prevent moisture that resides naturally in wood compromising the PVA dry film integrity that could result in areas of the mold surface that are not adequately protected.
