A moisture meter is a device that lets you see the future. It allows you to avoid mistakes where your furniture will – literally – fall to pieces. But convincing woodworkers to buy one is like trying to push water uphill.
This weekend, Brendan Gaffney and I were each working on some chair projects and got on the topic of moisture meters. Brendan has an idea for how to make one using a DIY circuit board and off-the-shelf parts that would make the meter quite affordable. It’s a great idea and he might write about it in the future.
But here’s the other option: Buy one today. I know it’s not a sexy tool because it doesn’t cut wood and is as romantic to use as microwaving a burrito. But it will save your butt and pay for itself quickly.
Today was a perfect example of this. I’m building a chair commission for a customer using walnut legs that I rived from a local log that had been on the ground about two years. The seat of the chair is air-dried walnut I’ve had on hand for a while.
After I shaped the legs yesterday from the riven stock, I pondered whether I should turn down the tenons so I could put the legs into the seat. The leg material felt a little cool to the touch, which usually means the wood is giving off moisture and is not at equilibrium with its environment.
A quick check with the moisture meter confirmed that the legs needed to sit some more. They all were 15 to 16 percent moisture content (MC), while the seat was 8 percent MC. That is a significant difference. If I’d assembled the chair’s undercarriage, there’s a good chance the legs would shrink and fall out of the seat.
And I would have a grumpy customer.
I prefer pinless meters because they don’t marr the stock, but really any moisture meter is better than no moisture meter. I haven’t, however, used all the brands on the market. About a decade ago, David Thiel and I tested a bunch of brands and didn’t find any significant difference among the meters’ accuracy. But more expensive ones (such as the one shown in the photos) were more durable and easier to set up.
— Christopher Schwarz