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Hardwood Record — Veneer & Panel Section 



March 25. 1917 



Letters from a Panel User 



Monroe, Mich., March 20 Every panel or woodworking man- 

 ufacturer using glue should determine by careful study exactly 

 how much heat the glue w^ill stand and its adhesive strength in 

 pounds per square inch. It is w^ell to make up several batches at 

 different proportions of water and glue, dissolved at different tem- 

 peratures, beginning with say 120 and not exceeding 180 degrees 

 and heat them different lengths of time. Make tensile strengths 

 of the various solutions, noting the breaking strain per square inch. 



Another test that should be made is the alkalinity or acidity 

 test. The best glues are neutral as to acid and alkali. Glues w^ith 

 an excess of acid should be avoided, especially w^hen used with 

 oak or other woods with strong acid qualities, as the acids in 

 the glue may unite with those in the wood in such a way as to 

 have a destructive effect upon the glue. In such cases glue will 

 granulate after a time and the work w^ill pull apart. The test is 

 made by means of litmus paper, which your druggist will sell you. 

 Buy red and blue paper. When testing for acid in glue dip a 

 piece of the blue into the solution. Should the color be changed 

 from blue to red or light red you will know^ that the glue is acid. 

 When testing for alkalinity, dip the red paper. 



Some panel manufacturers seem to have an aversion to ground 

 glues. They usually argue that inferior glues can be mixed with 

 good glue. There isn't much inferior glue made these days. Your 

 tests will reveal whether the glue is good or inferior. 



The foreign matter of glue is of an insoluble nature, and is 

 determined by dissolving five grams of the sample in hot water 

 and transferring to a glass cylinder holding 1000 cubic centi- 

 meters and made up to the mark with hot water. The cylinder 

 should be immersed in hot water to prevent the solution from 

 congealing. On standing for ten hours, the whole of the insoluble 

 impurities fall to the bottom. The clear liquid is run off and 

 the sediment decanted on a tared filter, well w^ashed with hot 

 water to remove all traces of glue, and then dried at 105 degrees 

 centigrade in the air oven. On cooling and w^eighing, the in- 

 crease in w^eight of the tared filter represents the foreign or 

 insoluble matter in the sample taken. The foreign matter is 

 greater in bone than in hide glues, the latter rarely exceeding 

 two per cent. 



The stronger the glue the greater the resistance offered by its 

 jelly to outside pressure. 



So many divergent methods for determining glue strength have 

 been formulated that lack of space forbids their discussion. I want 

 to say, though, that those depending upon chemical operations are 

 absolutely worthless. Those involving the use of special appa- 

 ratus supply results that in no way correspond to the commer- 

 cial value of the glue. The Lipowitz shot test method is now quite 

 generally known to all glue users. The writer, however, has had 

 splendid results by applying the so-called Fernbach method of 

 finger testing. ! believe that for practical commercial purposes 

 there is no better method of measuring the resistance of the glue 

 jelly than by means of the finger. The fourth finger of the left 

 hand is used, as it is the most sensitive of all. 



Some panel manufacturers w^ill complain that the glue does not 

 run uniform when in most cases the trouble lies in their own^ 

 glue room practice. The best glue in the world can be spoiled 

 by overheating or by leaving a small amount in the pot to sour 

 and then adding new glue to it. The new^ glue is quickly infected 

 with the bacteria contained in that already in the pot. Your 

 glue room should be kept clean. 



I w^ant to make this suggestion: Glue will keep perfectly for 

 many years, as long as it is dry. If in a wet or damp state the 

 bacterial action begins; so don't cook glue until ready to use, 

 expecting to hold it in jelly form. A. T. DEINZER. 



Guiana Letterwood and Mahogany 



Paramaribo, Dutch Guiana, February 17, 1917 Although long 



familiar with this product of Dutch Guiana. 1 have been so im- 

 pressed with a shipment of letterwood which 1 accidentally viewed 

 preparatory to export to the United States per S. S. "Prins 

 Wellem I" which left the colony recently, that I would like to 

 stir up the readers of HARDWOOD RECORD who may be inter- 

 ested in this commodity. 



These logs, being of selected grade and comparatively large 

 diameter, were a fine specimen of Dutcb. Guiana wood. Con- 

 siderable effort was devoted to their preparation for market, and 

 their appearance will undoubtedly attract the attention of dealers 

 in New York especially. 



This wood, although found in all the Guianas, appears to flourish 

 best in the forest of this country, and is considered one of our 

 most valuable bush products; the tree { Brosimum discolor) con- 

 sists for the most part of a very wide layer of white bark and a 

 comparatively red and black spotted core which is as hard as 

 ebony and weighs about eighty pounds to the cubic foot. This 

 core or hearlwood w^hich is most striking and has the peculiar 

 pattern of very dark lines (which give it its name), is roughly 

 scraped and shipped in the form of nice, clean logs ranging from 

 four to fifteen inches in diameter and four to ten feet in length. 

 The larger part of the total tonnage has been sent to the market 

 of Havre for distribution through France, where it is used ex- 

 tensively for canes and walking sticks, veneers, inlaid work, jewel, 

 glove and handkerchief cases, stop balls for darning stockings 

 and gloves, stamp and pin boxes, paper knives, ash and other 

 trays, cigar and cigarette holders, serviette rings, penholders, 

 rules, etc., and even fancy buttons. In the United States, where 

 there is only a limited sale at present, it is especially appreciated 

 for the paneling and wainscoting of rooms, for w^hich, of course, 

 logs of large w^idth are required. 



The total exports to Europe and the United States, in the years 

 shown below, w^ere as follows: 



1910 250 tons 



1911 156 tons 



1912 87 tons 



1913 113 tons 



1914 104 tons 



1915 33 tons 



1916 37 tons 



The exporter, who is an American, told me that from pieces 

 wasted in the preparation of his wood he makes a practice of 

 having a few little samples cut, which, after being well polished, 

 are distributed to wood brokers in New York; the idea being to 

 work up interest there. 



Also seeing one of the big K. W. I. M. punts alongside the vessel, 

 on inquiry I found it to contain fifty-one trees of our local mahog- 

 any being exported by the same party. These were purchased 

 from a plantation not far from the city. 



Lack of sufficient transportation at the present time is a great 

 handicap and calls attention especially to the United States Gov- 

 ernment for the necessity of establishing her own mercantile 

 marine. This want of bottoms undoubtedly retards the timber 

 industry here at this time especially; after the European w^ar 

 there w^ill be no difficulty in securing ample freight room for 

 Dutch Guiana woods, but how^ long w^ill this w^ar last? 



J. BARKLEY PERCIVAL. 



The time to inspect and pass judgment on a shipment of 

 veneer is immediately on its arrival, not when the time comes 

 to use it. 



As the telephone is a great convenience in the office, is there not 

 room to make use of it in the factory more than we do? Some large 

 plants have very elaborate private telephone systems, and they usually 

 find them g^ood investments. The question is, how many more could 

 use them to advantajje? There is room for study and experiment 

 fli:it may develop more than we have any idea of. Tiiis is stri(Mly a 

 telephone ajjc; even the modern farmer resorts to this instrument to 

 L-;tll on his neighbors, and there is just a change that the wooi] workers 

 may be letting a good opportunity lie idle here. 



