Pentachlorophenol is the most common of the oil-borne preservatives. The Type A is used only after gluing and can stain other materials and does not readily stain or paint. These preservatives, water soluble, are generally applied prior to gluing, then the wood is kiln dried and the members are glued to the required shape and size. The preservatives leave the member a light green-gray or brown color but wood can readily be stained or painted immediately since the wood is dry. Penetration of preservative into the sapwood is necessary to provide good protection.
Some species are highly resistant to penetration and are thus unsuitable for preservative treating.
Treatments will not penetrate all species. Kiln drying after treatment with water-borne preservatives is usually required by building codes for treated wood used inside buildings. It would not make sense to build or repair wood ships with green lumber so as to control the humidity within the ship. In general, longer curing times or higher temperatures are required for gluing pretreated laminations. Treatment may affect adhesive spread and assembly times.