Moisture meter recommendation and what is the desired %?
wil_d
| Posted in General Discussion on
Good day all. I’ve moved to a location where my access to good hardwood is limited. Not much in the way of suppliers, but several mills nearby. My questions: What is a good moisture meter to use on rough lumber to ensure it was actually dried at the mill (brand, model, etc). And second, what is the moisture content I should be looking for when buying this stock? I understand the wood will need to acclimate to my shop before working it, but not sure what the moisture percent should be when I make the purchase. Thanks in advance.
Replies
Its nice to have lumber already at the magic 6-8%.
Moisture meters are very varied I'm not that knowledgeable but I do not think you need a $200 meter.
I prefer pin over pinless b/c I can get a direct reading and don't have to refer a chart.
No chart for pin type meters? How do you factor in temperature, or don't you? "Pin-type wood moisture meters are especially sensitive to variations in wood temperature and because of this, high-quality pin meters are sold with temperature correction charts."
I have a Ryobi pinless with mode selection...hardwood, softwood, wall, masonry. Lumber from an outdoor yard at 10-12% is about normal. I bring it inside until it drops below 9% before I'll start in on it.
How do you get wood in the "magic 6-8% range? I have an old piece of furniture (white oak) that is around 100 years old and has been in my attic (humid south) for over 30 years. I used my new (inexpensive) pin meter on it and it read over 9% as compared to around 11-12% for some white oak recently purchased (supposedly kiln dried). Does this meter just read high?
I don't fall into that wood should be in this y%-x% range camp. I believe the moisture content needs to be at a level at equilibrium for your area. Check the moisture level of a piece of wood that has been in your shop for a couple of months or longer and you will get a good idea of what your target range should be. After all does anyone believe that the humidity level of the Pacific Northwest or Deep South is the same as the deserts of Arizona or New Mexico?
Moisture meters have there place but their data must be interpreted correctly wood can be too dry as well.
Wood comes into equilibrium with its surroundings. A good number in Oregon is going to be higher than New Mexico. And it will change by season, even spots in a house.
The equilibrium moisture content (EMC) is variable for different parts of the country. You might start out with wood at 8% but if you live in New Orleans where the EMC is 15.3% in August a work piece would eventually approach the EMC no matter how you finish it.
Indoor EMC is not the same as outdoor. In a house with HVAC, the moisture is very diminished. In the Northeast, we have 12 % equilibrium moisture in the wood outdoor but inside, it’s 8% in the summer and 6% in the winter.
Hey Wil,
I’ve used a Wagner MMC220 for a long time and been very happy with it. It reads to 3/4” depth and doesn’t mar any surface as it is pinless. I like pinless but that’s just me. It allows you to dial in different specific gravity settings to read any type of wood. After a while you’ll remember these settings, but can also write them on the meter.
As everyone else has said it’s easy to check stuff in climate controlled buildings in your area to know what MC you should be looking for. One more point for pinless in my opinion.
I would not hesitate to spend money on a good meter. I had about 500 bd ft of 8/4 “kiln dried” cherry delivered to my shop that read 30% MC a few years ago. Accepting that delivery would have cost me a lot more than the price of a meter well before getting into obvious problems and callbacks down the road.
From my understanding Wagner meters have been replaced/renamed by Orion meters. Don’t have experience with them but would hope they are as good or better.
I think any way to check MC is better than none. I certainly don’t think you need to spend hundreds, that just happens to be my experience and I don’t regret it in the least. Hope this is helpful and good luck!
I have a nice, slightly used pin type meter. It does a good job, but I will sell it for a very reasonable price. While happy with the pin type, I bought an Orion pinless meter primarily due to the extreme humid changes in the south and was tired of looking at the pin holes.
So...I did a quick Google search for ‘wood moisture meter reviews’, to see what I could find that might prove helpful. One of the near-top hits was on the Wagner website, ‘Wood Moisture Meter Accuracy: Pinless vs Pin-type (Guide)’, and they started by saying:
“ The most accurate moisture level test for wood is the “oven-dry test” because it weighs the wood. The more moisture wood holds, the heavier it is. That’s logical.
“An accurate oven-dry test requires weighing the wood before going through a round of oven drying and weighing it again after. It keeps going back into the oven until the wood weighs the same after a drying session as it did before it went in.
“The wood’s moisture level is expressed as a percentage of its total weight. The formula to calculate the moisture percentage is:
[(weight when before drying) – (weight after drying)]/ (weight after drying) = moisture %”
Well, okay, then. To determine the moisture level, one weighs the wood, oven dries it repeatedly, weighing after each drying episode, until the weight doesn’t change any more, then do the math, and—ta-da!—one knows what the moisture content was back before all the oven hullaballoo. That process sounds...unhelpful, at least in most instances.
Then they go into good vs. cheap moisture meters, basically saying the cheap ones aren’t good because they aren’t any good, but they usefully follow this with some discussion of pin-type v. pinless meters. Both use measurement of electromagnetic energy transfer (though it different ways) as an indirect means of measuring moisture content. To read more about the topic, visit the page at: https://www.wagnermeters.com/moisture-meters/wood-info/pin-moisture-meter/ (TL;DR: They prefer pinless meters, claiming they’re more accurate, don’t damage the wood, etc. Their models are all pinless—hmmmm—and start at MSRP of $379.)
Back in Jan. 2010, Roland Johnson did a review (here in FWW) of moisture meters available for under $200 (which he considered a reasonable price point), and he discussed how they work, how to use them, and more. [https://www.finewoodworking.com/membership/pdf/9558/011210064.pdf ] The article seems rather dated, however, and so I’m not sure how well, if at all, it applies to what’s on the market now.
My own experience suggests that there is certainly something to be gained as one goes from “cheap” (in my case, a General device for <$30 which varied significantly in measurements even within a single piece of wood done at the same time) on up to the Lignomat mini-Ligno E/D (a pin-type, but much more reliable and accurate, at about $100). I’m happy with the mini-Ligno, at least thus far.
All; thanks so much for the info and feedback. Extremely educational which is why I came here to get input. Although obvious, I had not considered the area or region one lives in and MC. As was noted, the ECM will vary depending on where one is (a duh moment for me). Will give the links included in comments a review and see what I can spend some money on. Thanks again for all of your insights.
I built five rather large multi drawer dressers when i was in florida from 11 to 12 percent moisture walnut .My two versions,the other three went to the kids,are in my Philadelphia apartment.Every drawer front height has gone from credit card space to at least two credit card space in four months.What counts is where the finished product will reside
It certainly does but it's not the only thing that matters. Wood that's not at equilibrium with your shop conditions will twist and warp before the project is even completed making assembly either difficult or sometimes impossible. I keep my shop humidity controlled as much as possible, usually in the 40-50% range, to match most home conditions in my area, but if I know the piece is likely to reside in a dryer climate I will simply make gaps a little tighter than usual and looser if I expect a more humid final location. These types of adjustments are easy to make and just require a little planning and common sense. Trying to make up for the twisted grain matched drawer fronts because I milled my wood before it had achieved equilibrium, well that's on me.
What I have learned decades ago is to buy my lumber a few months before using it. Never had a customer complaint.
Time is the great equalizer. Whoever said that must have been a woodworker because there is nothing like time to acclimate a board and make milling and assembly a pain free process. With proper acclimation it doesn't matter what type or how accurate your moisture meter is, your wood will be stable.
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