. Bulletin of the Department of Agriculture. Agriculture; Agriculture. 28 BULLETIN 1037, V. S, DEPAKTMEI^T OF AGRICULTURE. STEAMING GREEN STOCK AS A CONTROL MEASURE. METHODS COMMERCIALLY EMPLOYED. Steaming certain kinds of stock (green gum lumber, birch hubs, spokes, and sawed felloes of red or white oak) is sometimes resorted to as a means of reducing shipping weight by hastening drying or to even up the color and reveal defects in the wood. In the steaming of green gum lumber a large steel tank, or pre- parator, is employed. The lumber loaded upon trucks is run into this preparator and
. Bulletin of the Department of Agriculture. Agriculture; Agriculture. 28 BULLETIN 1037, V. S, DEPAKTMEI^T OF AGRICULTURE. STEAMING GREEN STOCK AS A CONTROL MEASURE. METHODS COMMERCIALLY EMPLOYED. Steaming certain kinds of stock (green gum lumber, birch hubs, spokes, and sawed felloes of red or white oak) is sometimes resorted to as a means of reducing shipping weight by hastening drying or to even up the color and reveal defects in the wood. In the steaming of green gum lumber a large steel tank, or pre- parator, is employed. The lumber loaded upon trucks is run into this preparator and steamed for perhaps 15 to 30 minutes at pres- sures of 20 to 30 pounds (figs. 13 and 14). Provided this lumber is then carefully open piled, it remains clean. When close piled or when exposed to ad- verse weather condi- tions, however, it mold almost as readily as untreated green lumber. Hubs, sawed felloes, and turned spokes green from the saw are sometimes steamed at atmospheric pressure. At one plant visited, green birch hubs were stacked in large cement boxes and subjected to exhaust steam for 24 to 36 hours, depending upon the size of the hub. At the end of that time the steam was shut off and the hubs were allowed to cool for perhaps 10 hours. The hubs were then carried to a ventilated warehouse and stacked, zigzag fashion, to provide for ample circulation of tlie air through the inside as well as around them. In this manner an even drying was secured. Two to three weeks was considered a sufficient length of time for the necessary air drying previous to shipping. During the warmer months, stock cars were used as means of transportation. The steaming of gum and birch is a comparativelj" simple process. But in the case of woods that check readily, such as oak, this treat- ment requires considerable Fig. 9.—A box car loaded with split billots upon its arrival at thie spoke mill. The method of loosely boarding the doorway, as shown in figure 8, is prefer- a
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