During the winter months, the extremely dry conditions of artificial heat present a unique movement-related issue. Think about it: your lumber supplier typically stores lumber in an environment that is not climate controlled. Whether it’s in an outdoor storage area or an indoor storage facility, it’s been subjected to the dry winter air; however, even that winter air holds more moisture than a heated room. Even heating systems with built-in humidifiers can take lumber to moisture levels below 6%. What that translates into is lumber that’s ready to dump a lot of moisture once it arrives in your wood shop. So what should you do about it? We have a few suggestions.
Don’t Turn Off the Heat
Okay, so we’re actually starting with what you shouldn’t do: don’t try to tough it out and deal with an unheated environment. Even if the temps were bearable for you to work in, if they dipped below 60 degrees (Fahrenheit), many of the glues and finishes you work with wouldn’t perform well. So do turn on the heat, but also realize that it’s sucking moisture out of your environment. Whenever you’re finding yourself especially subjected to static shock, realize that the moisture content of the lumber in the room will also be affected by the extreme dryness.
Understand the Risks
We’ve previously discussed the fact that wood movement is something we can predict, but not eliminate. In addition to the issues related to the kind of typical moisture-level swings that come with changing seasons, realize that artificial heat and the extremely low moisture levels produced by it can create unique problems. Even kiln-dried lumber can become unstable. You may notice visible cues, such as surface checks opening up. End checking may also become an issue.
Take Preventative Measures
In order to stop existing checks from opening up more, you can trim the ends as a preventative measure; that way the moisture will be shed at the ends instead of through the checks. In order to accommodate added trimming, you may want to purchase longer boards than your end result will require. If the tiny checks on the faces of boards do open up in the extremely dry conditions, they won’t cause major damage and will close up with a rise in moisture levels.
Another preventative measure you can take, in order to eliminate cupping and warping, is to keep a new pack of lumber banded. In a pinch, you can also weigh it down in order to prevent warping. Simply letting it rest for a day or so to acclimate to the extremely dry conditions can be extremely helpful in eliminating warping.
Not only do you need to account for the extreme dryness of the wood, but you also have to plan for its future. More on that in our next post.