HARDWOOD RECORD 



27 



prevent it or at least to reduce it materially. Since too rapid air- 

 seasoning is often to blame, the obvious thing to do is to retard 

 it by proper piling. The fact must not, bofl'ever, be overlooked that 

 there is danger of going to the other extreme and seasoning the 

 material so slowly that there is less from decay, sapstain and mold. 

 Logs, poles, posts and ties should not be allowed to lie on the ground 

 longer than absolutely necessary, especially in warm weather, but 

 should be elevated from several inches to a foot or more. The piles 

 of such material as well as of sawn products should be open enough 

 to allow ventilation, but not too open, the correct solution of the 

 problem depending on the material, the locality, the season of the 

 year and the exposure. Alternate wetting and drying lumber in- 

 creases very decidedly the liability to checking. 



The use of S-shaped thin steel clamps to prevent large cheeks 

 and splits is now a common practice in this country with crossties 

 and poles, as it has been for a long time in European countries. 

 These devices are driven into the butts of the timbers so as to cross 

 incipient checks and prevent their widening. In place of the regular 

 Shook which costs from two to three cents according to size, another 

 of crimped iron has been devised. Thin straps of iron with one 

 tapered edge are run between intermeshing cogs and crimped, after 

 which they may be cut off any length desired. The cost of these 

 irons is from one-half to one cent each. 



The time for driving S-irons of either form is when the cracks 

 first appear. The Germans have a clamp for placing over the end 

 of a pole to close a bad split before driving in the iron. The super- 

 intendent of timber preservation of an eastern railway company 

 that uses zinc chloride has a rule that where checks are not over a 

 quarter-inch in width, the S-irons shall be driven in before treat- 

 ment; in wider, they shall be driven in immediately after treat- 

 ment, since the injection of a water solution causes the checks to 

 close up. 



In India, where boxwood is cut into round pieces for export, each 

 piece is sawed down to the center along a radius, and this prevents 

 any other cracks, the large opening widening or narrowing according 



to the degree of moisture of the air. This is also a practice in 

 Japan. 



The tendency of logs to split emphasizes the importance of con- 

 verting them into planks or timbers while in a green condition ; 

 otherwise the presence of large checks may render much lumber worth- 

 less which might have been cut out in good condition. The loss 

 would not be so great if logs were perfectly straight-grained but 

 this is seldom the case, most trees growing more or less spirally or 

 irregularly. Large pieces crack more than smaller ones, quartered 

 lumber less than that sawed through and through, thin pieces, es- 

 pecially veneers, less than thicker. 



In order to prevent cracks at the ends of boards, small straps of 

 wood may be nailed on tliem ov they may be painted. This metliod 

 is usually considered too expensive except in the case of valuable 

 material. Squares used for shuttles, furniture, gunstocks and tool 

 handles should always be protected at the ends. One of the best 

 means is to dip tliem into melted paraflSne which seals the ends and 

 prevents loss of moisture there. Another method is to glue paper 

 on the ends. In some cases a broad paper is glued on to all the 

 surfaces of valuable exotic balks. Other substances sometimes em- 

 ployed for the purpose of sealing the wood are grease, carbolineum, 

 wax, clay, petroleum, linseed oil, tar, and soluble glass. The ten- 

 dency of solid porch columns to crack is largely ovei'come by boring 

 them out. AVoodworkers often have trouble with veneered spindles 

 where a solid core is used, since not only the core but also the 

 veneer checks. Some avoid this by not using any solid stock what- 

 ever, building up the core instead. In place of solid beams, built-up 

 material is often preferable as the disastrous results of season checks 

 are thereby largely overcome or minimized, and in some cases 

 greater strength is secured. 



With increasing scarcity of the better woods the importance of 

 exercising greater care to prevent unnecessary checking is becoming 

 more fully realized and steps are being taken to lessen the waste 

 from that source. 



' S. J. R. 



faroaiBsroa^TOTOiMMiiTOti^^ 



A l^ew Wood Preserver 



Dr. Allen F. Odell, assistant professor of chemistr}' in the 

 Louisiana State University, recently read a paper before the 

 American Chemical Society, in which he described "a new wood 

 preserver" which he thought might mean great things in hinder- 

 ing decay in different woods. The material which he proposes 

 using is called " cypressene, " and is an oil extracted from cypress 

 sawdust. From 275 gallons of crude sawdust he extracted 125 

 gallons of the oil, by baking or roasting in an iron retort. His 

 plan is to use this oil in treating timbers to prevent decay. It 

 is not very clear how he proposes to do this, but it is assumed 

 that the wood to be treated is immersed in the oil, either under 

 pressure or without it, and the oil will cover the surface and 

 enter the pores of the timber, somewhat as creosote does under 

 present methods of treatment. 



Dr. Odell calls cypress the everlasting wood, and believes that 

 he has found and extracted the principle which makes it ever- 

 lasting, and by impregnating other woods with this principle, they 

 will be rendered immune to decay. It is to be hoped that the 

 claims made for this discovery will be sustained, but several ques- 

 tions arise. In the first place, cypress lacks much of lasting 

 indefinitely when exposed to conditions which favor decay. No 

 wood lasts indefinitely under such circumstances. It is not claimed 

 by the discoverer that tests have actually shown that the oil 

 extracted from cypress sawdust prevents decay when applied to 

 other woods; but only that it will probably do so. There must 

 be actual trials and successes before a claim of the kind can be 

 accepted as a fact. Many schemes look well in theory but fail 

 in practice, and experience only can be depended upon to discover 

 defects, if such exist. 



Dr. Odell claims that the oil which he extracted from cypress is 

 what makes that wood durable, and he is probably right. It is 

 well known that the dark woods are generally more durable than 

 those of light color, and the greater durability is doubtless due 

 to the tannin they contain, mixed, of course, with other ingre- 

 dients deposited while the trees were growing. Decay is caused 

 by the activity of fungi which penetrate the wood, and the timber 

 is preserved by impregnating it with substances poisonous or ob- 

 noxious to the fungi. This is done artificially with creosote, and 

 many trees do it naturally with tannin and other substances while 

 growing. Some woods are darker than others because they store 

 up more of this matter. Dr. Odell 's method consists of extracting 

 this substance from a wood which has much of it and imparting 

 it to woods which have little. Theoretically, it looks feasible; 

 but in practice the first difficulty will be met when an attempt 

 is made to force the coloring matter into another wood. That is 

 the hardest thing which wood-treating engineers meet. It is next 

 to impossible to force the liquid into the pores of some woods. 

 The real invention that is awaited is not so much a new material 

 for treating wood, as a better method of forcing the material into 

 the pores. 



California redwood is as durable as cypress, and of much deeper 

 color. If the coloring matter extracted from cypress can be used 

 in a practicable way to preserve other woods, there is no apparent 

 reason why much larger quantities might not be extracted from 

 redwood and applied in the same way. Other dark-colored woods 

 which might be employed are: Sequoia, black walnut, mesquite, 

 black locust, catalpa, Osage orange and many of the south Florida 

 species. 



