Pro Primer W is a fast-curing,* two-component, resin primer for use over approved concrete substrates prior to application of Parapro and Terapro Systems. Can be covered with Terapro and Parapro Resins a minimum of 45 minutes following application and can be exposed for up to 6 months. Can also be used as a sealer for wood surfaces, plywood, and some vertical areas of concrete or approved substrates.