March 10. 1922 



HARDWOOD RECORD 





l^:xperts predict a heavy demand and small stocks of 

 K. D. lumber this Spring. 



Be prepared by installing a modern moist air fan kiln 

 now. 



As compared to steel our prices are relatively lower than 

 in 1913. 



Request our literature and learn where your dollars will 

 dry the most lumber. 



"The Kiln with a Circulation Yon Can Understand" 



B. F. STURTEVA^T COMPANY, Hyde Park, BOSTON, MASS. 



ATLANTA, GA. 

 NEW YORK, N. Y. 

 ROCHESTER, N. Y. 



DRY KILN EXPERTS LOCATED IN 

 BOSTON, MASS. 

 PHILADELPHIA, PA. 

 SEATTLE, WASH. 



CHICAGO, ILL. 

 CINCINNATI, OHIO 

 SAN FRANCISCO, CALIF. 



the kilu c-ouditioii, the fact tliat this conjitioii was regularl.y inspefteil, 

 and when it was inspected. The gauze was renewed before each kiln 

 run, regardless of appearance, which is very important. 



Such an arrangement is very reliable, inexpensive, easy to care for, 

 and it is most convenient. The writer has used it in many instances 

 with best of satisfaction, and in preference to expensive recording 

 hygrometers, when the latter were readily available. 



Such an arrangement, accordingly, solves the control of humidity 

 and temperature above the gum lumber and will reduce the loss in 

 top layers to a minimum. 



It is desirable to weigh down these top layers if it can be done, and 

 thus stop all loss from twisting, but this requires considerable weight 

 and special apparatus. Any such special arrangement will pay biy 

 returns where large quantities of gum luml.ier must be dried. Thi'i 

 the writer can attest from actual extended experience. On one large 

 operation requiring big quantities of wide, long (and consequently 

 expensive) boards of gum lumber (sujjposedly Ked Gum, but in fact 

 anything which would cut width and length), there were available 

 two old Nichols kilns from whicli the accordeon heating system 

 had been removed, but which retained the hydraulic arrangements for 

 lifting the same. 



One Way of Holding Down Gum 



In these a properly subdivided heating s.ystem was installed in tli" 

 spaces between the lower beams, and over same was placed a strong 

 loading platform properly latticed. The upper frame, carried by the 

 water rams, was extended by means of suitable I-beams, to 28' length, 

 and on top of this was piled, properly distributed, all of the Hat 

 iron scrap, which the four rams would lift (about 20,000 poumls). 

 Between the piling floor, the upper frame, when fully lifted, ami the 

 four rams, each kiln would hold about 8,000 board feet of gum. This 

 latter w-as carefully piled, in the manner indicated at the beginning 

 of this paper, and then the weighted jilatform was let down on the 

 top of the piles which had been covered with 2" planking. The mois 

 ture content of this lumber was about 50 percent when put into tlie 

 kiln. It was steamed from cold to 17.')° (at ceiling), and the steam 



wa.s kei>t .slowly going into the kiln, until the ITS' actually "held," 

 all of which could be positively read on the recording thermometer, 

 arranged as hereinbefore explained. All ventilation lieing hermetically 

 sealed, the kiln was allowed to cool, at practically saturated air con- 

 dition, to the starting temperature of 130° of the Madison schedule 

 ><'o. 3. This schedule the writer has found to be more sure of suc- 

 cess than the severer schedule No. 2 recomnu-nded by the laboratory 

 for red gum. 



After starting, this No. 3 schedule was followed, strictly on basis 

 of numerous moisture samples, to the end (which in this case meant 

 ') iiercent and no more), when the lumber was tested for ca.se- 

 hardening, and .steamed for one hour to about 1.50°, if it required it. 

 It was then jierniitted to cool below 100° before removal. The re.sult 

 of many such dryings in these kilns was as perfect gum himbcr as 

 can be obtained, free from any kiln loss. Not only could the lumber 

 not move, but the pressure of the weight was so great that it could not 

 shrink where it was held by the stickers, and most of the boards had 

 a scalloped appearaiu'e, having shrunk between the stickers, and not 

 at sticker contact. This at first raised the question of possible split- 

 ting of the wood between stickers, but careful examination disclosed 

 that the fibres simply, \yerc held in tension without splitting and 

 became set in this condition. 



Could Build Special Gum Kilns 



It may Iw remarkeil that these two kilns were too small for any 

 but te.st purposes, whicli is true, but the infonnation obtained war- 

 ranted all trouble and. expense, it enabled gum drying in other kilns, 

 holding as many as 40,000 bf. each, with but minimum loss. It 

 would be entirely feasible to construct kilns, moderately expensive, 

 which would surely prevent the damage to gum lumber by twisting 

 ami warping, if properly operated. 



For the benefit of those who are not familiar with the schedule No. 3 



mentioned, same is herewith re printed. Do not expect any results 



from its u.se, unless you are willing to make the temperature and 



■ humidity changes only on the basis of your definite Vnoidedgc of the 



tCotitiiitu-tl Oil ituije 27) 



