A wood product is made from treating wood with two solutions, in series, including a penetrating solution and a topcoat composition. The penetrating solution is made up of boric acid, a metallocene catalyst, a free radical initiator, a first film-forming polymer and an adhesion promoter. The topcoat includes a second continuous film-forming polymer. Application of the penetrating solution to the wood gets the solution into the wood to cross-link boric acid with cellulose fibers, then the topcoat forms the continuous film. The topcoat seals in the penetrating solution so that it does not leach out during subsequent exposure to water and weather, allowing soluble salts such as borax to migrate and infiltrate deeper into the wood. Microbiological growth is prevented by several mechanisms.