Encore Coatings Encore! PT-1 1 gal PreTreat - Adhesive Penetrant for Wood is a water-thin blend of proprietary micro-resins that is sprayed through a conventional pump up sprayer onto wood decks. Decks that are treated with Pretreat prior to being coated with Encore will last longer because Pretreat helps to fix the dimensional stability of the wood. Expansion and contraction is what causes wood to deteoriate. Fix the dimensional stability and both the structure and the coating will last longer. Pretreat penetrates into the cellulose fibers of the wood and literally glues the fibers together. Pretreat dries quickly and leaves behind a clear film that has molecular chain extensions that cross-link to the Encore coating. Pretreat’s ability to cross-link with Encore creates a single coating that protects your wood deck.