Moisture meter on cold wood

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phatdonkey

Member
Dec 15, 2014
153
West Norriton, PA
I know it is said that woods moisture content should be taken at room temperature ~70*. Is there a percentage that it is off by when cold/frozen, or is it so varied that it is best to just check it at room temperature?

I ask because I'm low on wood and will be gathering some possibly close to seasoned wood, and don't want to see 20% while rooting thru stuff, to get home and have it be 30% once its warmed up.

Any theories, or tests that have been done that can lead to a rough estimate?
 
I'm not possitive but I thought I read somewhere that the MC will read higher when cold / forzen?
 
I thought it was the other way around, but I could be mistaken. I would assume as the wood warms up the moisture in it relaxes and passes current better than when frozen. I'm new to burning, but I'll tell you what, everything about it fascinates me. I can't wait to have a kid that is old enough to do a science project. It will most likely be on seasoning fire wood. Haha.
 
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Cold causes mm to read low by at least a few percent. I would guess mine reads between 3-5 low at around 32 degrees.
 
If you are getting low on dry wood, best to mix some 'not quite dry' with the dry when burning. I had to do that toward the end for the last two years and it works better than burning the not so dry on its own.
I've always brought the fresh split in to dry before reading. Maybe take a frozen and room temp reading and let us know.
 
It is very interesting, sometimes you have to be a pioneer.
Do a test, do your readings where you need to. Use the data you have. But mark the tested pieces, bring some inside with you and retest the splits.
It wont be a total answer for you now but help you make future decisions.
And let us know.
I personally test mine outside in the cold and accept the rough estimate as is.
But Im not buying.
 
I just read your other thread. Use fresh batteries and keep the meter warm, like in a jacket pocket. I dont know if this does anything but I worry about batteries losing charge in freezing temps.
It may not help but it wont hurt.
 
My 2 cents worth,
Its what goes in the fire that counts, bring some in and test. Its a science that will drive you mad....too wet / too dry. I havn't tested since I loaded the wood shed.

bob
 
Maybe do the opposite. Take a known seasoned piece, put it outside to freeze and then test it when it's cold.
 
These are all great ideas and i will post my findings. Im pretty low on wood now. Maybe another day or so and its only 45° here, but it may be enough temp change to show a difference.

Time will tell.
 
Maybe just grab what you can, test it on site from your instincts of whats best. If you can get a fair amount of wood, maybe just focus on getting it home.
 
Or skip the whole testing thing for later. Just Grab wood.
I just split some really old dead white oak. I got from my tractor mechanic. It was cut by a road crew about 10 years ago and was laying in cattails. And I split it and stacked it in December.
The numbers were jumping all over the place. From 50% to 34%. Its a total bummer because the wood looks and feels bone dry. But its still heavy.
Surprising in a disappointing way.
 
I hear ya. The goal is to just get wood home. Just looking to have the advantage of getting some drier stuff while im out there.
 
Or skip the whole testing thing for later. Just Grab wood.
I just split some really old dead white oak. I got from my tractor mechanic. It was cut by a road crew about 10 years ago and was laying in cattails. And I split it and stacked it in December.
The numbers were jumping all over the place. From 50% to 34%. Its a total bummer because the wood looks and feels bone dry. But its still heavy.
Surprising in a disappointing way.
There's a big difference between moisture from rain/ground than sap/moisture in fresh wood. You should be able to dry your wood quickly.
 
In below freezing temps I give splits 48 hours in my garage at +55dF before I think of reaching for the moisture meter.

I bought a cord of fire killed dead standing spruce in the last couple weeks, reputable seller stated on his website that after 24 hours in a heated garage the wood would meter 18%.

I am bringing in wood for next winter anyway, but everybody with a Ford Ranger and a Poulan Wild Thing that can get a permit is cutting out of a pretty fair sized forest fire we had close to town a couple years ago.

I got a right generous cord from the guy, knew I would, have done business with him before. 24 hours later in the garage, sure enough, freshly split faces of the "fire killed standing dead two years" spruce metered 18%. 48 hours after delivery, more freshly split faces off the same load come in consistently at 22-28%.

I don't know how well frozen water conducts electricity, but not as good as liquid water for sure.

In above freezing temps for a couple weeks or so - including overnight lows above freezing- then I will keep wood in my heated garage for 24 hours and then meter freshly split faces. Below freezing, i wait 48 hours before I think I have a number I can count on.
 
Did a totally unscientific experiment last night just out of curiosity from reading this. Split a piece that has been inside the house all week. It was 17.4%. I took that same piece and sat it out in the gazebo last night. It was in the mid 30's overnight. I brought it inside and split it again this morning. The reading was 14.5%. It seems cold does in fact give you a lower reading. DSCN1015.JPG DSCN1016.JPG
 
Well If you read the manual for the meter ( I know, that's not in the man code ) most will state that what you are checking the material should be at or very near room temp for a decent reading.
 
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I don't even know if it came with instructions. I was like a kid on christmas and ripped the package open, slammed batteries in it and went to the wood pile. Im sure it probably said something along those lines. Thanks blades.
 
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