Q: I have started making furniture out of beetle-killed pine. The blue streaks add character indeed. Unfortunately, the suppliers pine is about 16 percent MC and I think I need to get the lumber down to 7 percent MC. The supplier cannot or will not do this for me. What can I do?
A: I am delighted to hear that you are using this pine which needs to be removed from our forests before it is burned and then nobody benefits.
For construction, 16 percent MC is fine. As you know, furniture in use is around 7 percent MC (a little drier in the wintertime and a little wetter in the summertime in much of the United States. It is indeed prudent for you to dry this material a bit more before you use it to avoid warping and shrinking problems in-use. However, pine does not machine well under 9.0 percent MC (and in some cases 10.0 percent MC); that is, the wood is brittle and splits and machines poorly. So, you should probably target closer to 10 percent MC with all the pieces between 11.0 percent and 9.0 percent MC, especially if the product you are making is sensitive to size changes.
Although you will have to stack the lumber on stickers, you should be able to dry it from 16 percent MC to 10 percent MC in a heated room (about 120 F and 38 percent RH. If the humidity is too high, exhaust air from the room and add drier outside air that you heat up. An alternative is to use an electric home-type dehumidifier to control the humidity and to operate at room temperature. If you are in a sunny location, you might also be able to use an trailer from an 18-wheeler that you paint black. Gaa in, a small exhaust fan will move the moist inside air to the outside. In this trailer, you again want to target about 38 percent RH.
If you do put in a dryer, you should probably check with your accountant, as a kiln is a piece of equipment, to see if the equipment can be depreciated when doing taxes.
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