222 



SELLING LUMBER 



Chemicals 

 That Effect- 

 ually Preserve 

 Wood. 



( Painting 

 'with Pre- 

 servative 

 Has Little 

 Value. 



370 square yards, or 7^2 million cubic feet, of which 2,679,906, 

 or 91.3 per cent were Southern yellow pine. The amount of con- 

 struction timbers on the Atlantic and Gulf coasts treated in 1915 

 equaled 106,097,328 board feet, or about 75 per cent of all con- 

 struction timber treated in the United States. While these figures 

 show a very large increase over the amount used ten years ago, you 

 will note that they deal almost entirely with ties, construction tim- 

 ber, piling and paving blocks. The amount of lumber actually 

 preserved is still very insignificant. 



The chemicals used in the artificial treatment of lumber which 

 have survived the test of time are very few in number. At the 

 head of the list is coal-tar creosote, sometimes known as dead oil 

 of coal tar, a substance derived from the distillation of coal tar, 

 either from retort gas works or by-product coke ovens. Creosoted 

 lumber will cost anywhere from $10 to $25 per thousand feet 

 board measure, added to the cost of the lumber, depending upon 

 the amount of oil used, initial cost of oil, freight, etc. The next 

 in importance is zinc chloride, a water-soluble salt, the price of 

 which is very high at the present time, due to war conditions. The 

 treatment costs from 5 to 7 cents per cubic foot. Mercuric chloride 

 is used in two plants at the present time, both located in the New 

 England states. The cost is about the same as zinc chloride. 



These preservatives are applied and forced into wood by dif- 

 ferent methods. Ordinary painting with a preservative has com- 

 paratively little value. Effective preservation can be obtained only 

 in case the preservative is forced into the wood so that all of the 

 sapwood is penetrated. In order to do this the wood must usually 

 be in a thoroughly air-dried condition. Prospective users of lum- 

 ber are cautioned to guard against the improper use of the host 

 of patented or trade marked so-called wood preservatives. These, 

 in the first place, cost very much more than any of the three com- 

 pounds above mentioned. In the second place, it is usually ad- 

 vocated that they be applied with a brush, and, entirely aside from 

 any of the other claims made for such compounds, these two points 

 are of sufficient importance to warrant exceedingly careful study 

 on the part of the prospective user before paying the more or less 

 excessive prices, particularly when good creosote can be bought 

 for not to exceed 25 cents per gallon. 



The simplest method for treating lumber, applicable par- 

 ticularly to the small user, is the so-called open tank process. This 



