Clear Pre-Form is a transparent, penetrative polyurethane wood form sealer that extends the life of plywood forms. It does this by reducing the absorption of alkaline bleed water. The wood sealer improves concrete surface appearance by preventing soluble wood sugar migration, which can cause concrete surface retardation. Ideal for use with dimensional lumber, plywood, wafer- wood, OSB, fiberboard and particle board concrete forms and rustication strips. When properly used, Clear Pre-Form is a cost-effective alternative to overlaid plywood. This is particularly true when panel reuse doesn't justify cost of overlaid plywood, yet exceed reuse capabilities of plywood forms.