Setting Pitch with a Solar Kiln

If the kiln doesn't get hot enough from sunshine alone, try some supplemental electric heat. July 10, 2007

Question
I will be drying some white pine in my solar kiln this summer. I anticipate getting temperatures up to 160 degrees for approximately 4-5 hours during a hot summer day. I do not have any supplemental heat source for the kiln. I will be primarily drying 4/4 stock. Does anyone have experience with solar kilns setting pitch? Will these short durations of high temperatures be enough? What duration of high temperatures do people shoot for to set pine pitch?

Forum Responses
(Sawing and Drying Forum)
From Professor Gene Wengert, forum technical advisor:
If you get this 160 F air blowing through the lumber, it will evaporate the troublesome pitch in 24 hours total.

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From contributor E:
Last fall I had a load of EWP in the solar kiln and got it down to the proper moisture. Then I wanted to set the pitch but the weather was cooler. We had sunny days, but could only raise the kiln to 130. I just set an electric heater in the kiln, shut all vents, let the fans run, and presto - it was nearly 170. This not only set the pitch but did away with any critters. The warmest days inside the kiln in my area are from mid April to early June, then August through September. When the sun's rays hit the glass perpendicular, that's the highest heat. In late June and July the days are hot, but the sun is overhead and the sun rays do not hit the glass perpendicular.