Serrated kiln sticks and top load substantially reduce warp in southern pine studs dried at 240°F

Abstract

Sharply toothed aluminum kiln sticks pressed into 2 by 4's cut from veneer cores, with a clamping force of 50 to 200 pounds per stick-pair per stud, significantly reduced warp from that observed in matched studs stacked on smooth sticks with a top load of 10 pounds per stick-pair per stud. When dried in 24 hours to an average MC of 8.1 percent (standard deviation of 2.3 percentage points), studs pressed between serrated sticks had crook (0.13 inch), bow (0.21 inch) and twist (0.16 inch) averaging only 54, 70, and 46 percent of that observed in studs secured between smooth aluminum sticks. For studs gripped between serrated sticks, maximum observed crook (0.33 inch), bow (0.72 inch), and twist (0.68 inch) were only 28, 53, and 44 percent of that noted in the studs stacked on smooth sticks. All studs were surfaced on two sides to a uniform thickness of 1.78 inches prior to drying. Stud sides were left rough so they had width variation normal for the studs from the mill sampled; average width was 4.2 inches. To exploit the idea of heavy top load combined with serrated sticks, a killn design is proposed.

Citation

Koch, Peter. 1974. Serrated kiln sticks and top load substantially reduce warp in southern pine studs dried at 240°F. Forest Products Journal, Vol. 24(11): 30-34