. . . some modern preservatives
.PENTACHLOROPHENOL, often called Penta in trade language, is the name of the main ingredient of a widely used and very effective low-cost wood preservative. It comes ready to use, diluted in oil for easy spreading and quick penetration, whether it is brushed on the wood surface or used in a pail or large can for soaking the cut ends of posts or boards. It can be painted over with most outdoor paints when it has thoroughly dried.

.ZINC AND COPPER NAPHTHENATES are chemicals which are not only odorless, but they, too, can be painted over when dry. Copper Naphthenate leaves a pale green stain in wood, something to consider if you are not using an opaque-finish paint. Zinc Naphthenate preserves the natural color of the wood and may be used under clear varnishes, lacquers, shellac, and other colorless finishes. It is a little more expensive than Copper Naphthenate. Both preservatives may require a sealing coat of shellac or an opaque primer-sealer before final paint coats are applied to the wood.

.COPPER SULFATE crystals dissolved in water can be used effectively for treating wood, particularly green, unseasoned kinds. Use 11/2 pounds of the Copper Sulfate to 1 gallon of water, dissolving it in a watertight wooden barrel. Fill the barrel to a little above the depth to which the wood is to be buried and let the wood posts soak in it for a half-day or so to permit deep penetration; then brush in the liquid well on the parts of the wood which are not being buried. It will leave a bluish stain, be warned, so that you must count on painting the wood rather than finishing it in its natural color.

All of the modern preservatives can be either brush-applied or used to soak the wood. Because the efficiency of the preservative is measured by the depth to which it penetrates, soaking is obviously the better method. You will, therefore, find that soaking cut ends (particularly those of fence and trellis posts) is advocated in the text of this book.