Timber Preservation On the Coast

By Mason E. Kli4e, St. Helens Creosoting Co. Address Before Lumber Salesmen's Club of San Francisco

Retail Men Interested

It is perhaps difficult to understand how the retail lumberman- is inlterested in the creosoting industry since it raiely happens that he handles a schedule and secures a commission. Some might even assume that the quicker a stick of timber decays ihe sooner a netv piece can be sold. However, this would be a short-sighted -policy and I tell you, Gentlemen, you are interested in any method for co-nserving our forest resources. One has but to glanc,e at the compiled figures of our annual cutting or visit the once tim6ered areas of the Northwest to realize that this prodgction cannot continue forever. Therefore, every time you permit an untreated stick to be installed in a.n exposed position you are simply discounting your ability to remain in the lumber game in the future.

Theory of Timber Preservation

There are many destructive agents which attack-wood, foremost among which are decay, insects, marine borers, etc. Perhaps the most active and more common of these is decay.

Thousands of exact laboratory tests have established beyond all peradventure that the true cause o-f decay in timbe.r ire low iorms of plants called fungi and bacteria, which attack cellulose and lignin, rapidly destroying the piece. To preserve wood from decay, it is, therefore, absolutely esseniial to protect it from the attacks of these organisms.They require certain amouhts of heat, air, moisture and food in order to live. To remove any one of these essentials would be to kill the organism and preserve the wood indefinitely. You are all familiar with the fact that furniture which is kept absolutely dry in your homes does not decay. It is obvious that an efficient preservative must accomplish the control of one of these four factors and -equal- ly as apparent that in geheral practice it is impossible to control- lhe heat, air and moisture surrounding wood set subject to decay. The only remaining course is to poison the wood constituting the food supply.

Hundreds of chemicals and compounds have been advocated and tested to preserve wood from decay, but only a few of them possess lufficient merit to justify their use for this purpose. A great mahy experiments, extending over the last- seventy-five years have reduced the number of preservative ag-ents, practically efiective, to creosote and zinc chloride. -Due to its inorganic nature zinc chloride is soluble in water and therefore leaches from the wood; in time leaving it ready for attack. It is evident that this agent cannol be used at all in marine work. This is hot the case with creosote, which has proven the most effective preservative known. Many timbers treated with creosote ind exposed in the most severe positions have successfully withstood all attacks for periods ranging from forty to' fifty years.

Creosoting, contrary to the general opinion, ig hot a recent innovation and was known by the ancient Egyptians. While I haven't a recent communication from the old boy himself I'm confident that the real reason King Tut's bohes are in existence today is due to a generous application of creosote'

Source Of Creosote

In the manufacture of steel it is customary to coke coal in the ovens producing therefrom coke ,producer gas and coal-tar. Thii coal-tar is later distilled and produces an almost endless list of derivatives, such as Phenols, Napthalene, Anthr?c€o€, which is used as a dye base, and an oil known as creosote. Creosote may, therefore, be termed a by-product of the distillation of coal-tar, with a high toxic value against the enemies of timber.

Methods of Treatment

In treatment the m'aterial is first lobded upon small cars, or trams and then placed in steel cylinders called retorts. These retorts are usually 7 f"eet in diameter, 130 to 150 feet long and of heavy 1 in. boiler plate capable of withstanding high pressure.

Undlr iome climatic conditiohs it is possible to stack the material upon a yar{ for a sufficient period of time to become thoroughly-seasoned by Nature, however, in climates, such as the Paiific Ncjrthrvest, where the annual rainfall is large, this is not practical. Likewise few--Engineers of the Coist have given- timber preservation sufficient consideration to be ab--le to anticipate their requirements far enough ahead to permit natural seasoning and it therefore became necessary to devise some method of accomplishing this end bv artificial means. -Thru many experiments and refinements--the process has been broughi down to its present, highly efficient state and is known as the boiling under vacuum process. You all know that it is possible to evaporate water at a lower temoerature under-a vacuum than at atmospheric pressure, 'consequently the removal of the moisture content is accomplished 6y this method rvithout subjecting the timber to the cletrimenial efiects of high temperatures. It is interesting to note that material seasohed by this process is sub-