Whether you’re drying your own mill-sawed wood or just working with pre-sawed lumber that’s been sitting outside for a while — and maybe got a little rain — the moisture content of the material you use may well make the difference between success and failure in your next woodworking project. But besides waiting around until you’re pretty sure the wood is “dry,” how do you know how moist your stock is? Easy: You apply a wood moisture meter.
The first time it really dawned on me that wood can hold varying amounts of water was when my father and I were off-loading some oak he picked up from a mill in Mississippi. It was finish-sawed, but not dried. (His intent was to dry the wood back at his house in Texas.) He bought just over 1,000 board-feet in the form of 12″ x 1″ (and some 2″) x 10′ boards. They were heavy. Seriously heavy. As in, the two of us could just about pick up the 2″ boards and the 1″ boards were difficult.
A couple of years later we moved the lumber from where we originally stacked it to another place about 40′ away, and guess what? It was significantly lighter. Besides the length, each of us could easily pick up the 1″ boards, and the 2″ boards were easy for the two of us. The wood had dried that much, even just sitting under an open-around-the-bottom tarp.
Sadly, my father never got around to doing anything with the pile of oak before he died, though it’s now resting in a safe place waiting for Sean to take a run at it with his soon-to-be-installed planer. So when I saw the low-buck moisture meter (pictured) in the tool corral at the local big box, it reminded me of the whole process.
The meter seems pretty simple: It measures the resistance between the two conductive prongs, interpreting the result in terms of moisture content. (In fact, I’d bet this works in a surprisingly similar fashion to home body fat percentage testers.)
But I’ve got a few questions that maybe some of you more experienced Toolmongers can answer. Do the cheap meters like this suffice for woodworking purposes, or would one require more accuracy than they can offer? I noticed that the Amazon reviews for the one above, while all pretty positive, indicate that purchasers are using it for other purposes, like detecting the extent of water leaks or checking to see whether firewood is dry enough to burn.
A quick look around the ‘net shows that wood moisture testers start around $13 and run up to around $150. Admittedly, the $150 models look a good bit more carefully-made. But are the electronics that more accurate?