What's a Good Moisture Content?
What is a good moisture content for working wood? What I have is currently at 14 percent
Wood for furniture making should be in the region of 6 to 8 percent moisture content, depending on the area you live and your local humidity conditions. Your wood is too wet. It is typical of much of the lumber that carpenters use to build homes, which is fine for houses, but sucks for furniture. If your shop is dry, bring the stuff indoors and let it sit a couple of weeks to acclimate to the shop's humidity levels. If you can, stack and sticker the pile so air can circulate around it, and place some weight on top. This will promote even drying with less chance of warping.
The "right" moisture is when the wood is at "equilibrium'" with the moisture in the air around it. When the wood is balanced with the air, it is the most dimensionally stable it will ever be. Get a chart showing EMC (Equilibrium Moisture Content) along with the average relative humidity in your geographical area. Match the two to know your best percentage number. Understand, it takes time for the wood to come into equilibrium, or balance. Cut a board and measure the EMC at the core as well as at the surface to know if the wood is stable or changing. Once the wood is at equilibrium, your joints will fit and stay that way. Here is a USDA Forest Product handout that might be interesting: http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/ch03.pdf
This article originally appeared in the Woodworker's Journal eZine.
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