It is one of the most effective wood treatment methods, and is used for longterm preservation where severe decay conditions exist. This consists of soaking dried wood in chemical preservatives for periods up to several days, but seldom less than 24 hours. A hot and cold bath method accelerates the rate of absorption. Dried wood is soaked in a hot preservative solution for two to ten hours, then transferred to a cold solution for one to six hours. Commercial operations can spray or dip lumber to control sapstains, while home applicators can use a paint brush.
Surface treatment is inadequate for severe decay conditions.
Treatment of Standing Poles, Posts and Beams. Treating wood already in place presents special problems. Poles are most susceptible to decay near the ground-line. Alternately, chloropicrin or metam-sodium can be injected into drilled holes which are then plugged with dowels. Wood treatment chemicals are safe if they are handled properly.