wood moisture

wingsfan Posted By wingsfan, Mar 11, 2013 at 1:40 PM

  1. wingsfan

    wingsfan
    Feeling the Heat 2.
    NULL
    

    Dec 1, 2008
    370
    77
    Loc:
    Jackson,Mi.
    I know wood will give you a different moisture reading depending on if it is cold or room tempeture, But what is the diferance? If you get a certain reading while the wood is cold, will it read less or more when the wood is at room temp?I'm guessing it would be lower at room temp., but just trying to find out for sure.
     
  2. Ashful

    Ashful
    Minister of Fire 2.
    NULL
    

    Mar 7, 2012
    9,062
    3,783
    Loc:
    Philadelphia
    It depends on how you measure it. The moisture content is not changing, but the conductivity is changing, so you will see a thermal coefficient if you use a cheap ohmic moisture meter for your testing.

    Most conductive/ohmic meters are roughly calibrated to 20C, and will read higher when the wood is warmer than 20C, or lower when it's colder than 20C. I say "roughly", because it varies more widely by species... so unless your meter allows you to select different ranges for different species, its measurement is only a very rough estimate of moisture content. It's usually good enough for a wood burner's requirements, though.

    An acceptable correction factor used by some temperature-compensating ohming meters is 0.1% MC per degree-C, above or below 20C.
     
    Wood Heat Stoves likes this.
  3. wingsfan

    wingsfan
    Feeling the Heat 2.
    NULL
    

    Dec 1, 2008
    370
    77
    Loc:
    Jackson,Mi.
    Thanks Joful, I was wondering because I had some ash outside that said it was 19%, at about 30 F., and I was wondering if it was really good to burn , once it came in and got up to room temp.
     
  4. Ashful

    Ashful
    Minister of Fire 2.
    NULL
    

    Mar 7, 2012
    9,062
    3,783
    Loc:
    Philadelphia
    Using 0.1%/*C, it should read roughly 21% when it finally reaches room temp, assuming I can still do math in my head. Now as to how accurate that measurement is with your meter... that's a whole other debate.
     
  5. Wood Heat Stoves

    Wood Heat Stoves
    Minister of Fire 2.
    NULL
    

    Jun 12, 2009
    1,905
    14
    Loc:
    Nevada City, California
    Even without a moisture meter and despite the temperature you can tell pretty well if wood is good to burn. Cracking and splitting on the ends, the overall feel of the weight when you pick up a piece, and especially the feel and smell of freshly split wood are good indicators.
     
  6. PapaDave

    PapaDave
    Minister of Fire 2.
    NULL
    

    Feb 23, 2008
    5,740
    2,221
    Loc:
    Northern MI - in the mitten
    Sorry, but cracking/splitting on the ends is not always a good indicator.
    I've got some Oak that I cut down late last year.....very wet, that had some cracking/checking on the ends within a month.
    That stuff isn't gonna be ready to burn for a little bit.;)
    The Oak in the shed that's been c/s/s for almost 3 years also has the cracking/checking. That stuff is ready to burn.
    Maybe it works better in your climate?
     
  7. Ashful

    Ashful
    Minister of Fire 2.
    NULL
    

    Mar 7, 2012
    9,062
    3,783
    Loc:
    Philadelphia
    I don't think he was saying cracking on the ends means it's dry. It's just one of several signs you need to see.

    Oak does seem to split faster than the rest. I have a whole pile of larger oak rounds sitting in my wood lot, felled three weeks ago, and bucked two weeks ago. They've already got some splits opened up a full inch on each end.
     
  8. Backwoods Savage

    Backwoods Savage
    Minister of Fire 2.
    NULL
    

    Feb 14, 2007
    27,815
    7,368
    Loc:
    Michigan
    But that cracking on the ends is something a lot of folks like to quote and state that it shows the wood is dry. Dave was correct. The cracking on the ends of the logs shows only that the ends are drying. It says nothing about what the inside of the wood is like.
     
    Trilifter7, ScotO and Ashful like this.
  9. Wood Heat Stoves

    Wood Heat Stoves
    Minister of Fire 2.
    NULL
    

    Jun 12, 2009
    1,905
    14
    Loc:
    Nevada City, California
    All that's true, the checking on the ends is just one indicator. Splitting the wood and checking the inside of the split with a moisture meter is the best, but feeling the moisture and smelling the aroma of the wood on a fresh split works well too. If you're used to how heavy a dry piece of the same type of wood feels, the weight of a moist piece will feel al lot different also.
     
  10. PapaDave

    PapaDave
    Minister of Fire 2.
    NULL
    

    Feb 23, 2008
    5,740
    2,221
    Loc:
    Northern MI - in the mitten
    But, I bet they aren't dry......just dry-ing. Might not be ready to burn either.
    Well, not enough so that I'd want to burn 'em. Been there and done it.
     
    Backwoods Savage, Nixon and ScotO like this.
  11. Ashful

    Ashful
    Minister of Fire 2.
    NULL
    

    Mar 7, 2012
    9,062
    3,783
    Loc:
    Philadelphia
    Oh, definitely not! 30" diameter oak rounds don't dry in 3 weeks! :lol:
     
    Backwoods Savage, ScotO and PapaDave like this.
  12. bag of hammers

    bag of hammers
    Minister of Fire 2.
    NULL
    

    Jan 7, 2010
    1,444
    450
    Loc:
    Northern ON
    I've had pretty good luck so far with that approach -not 100% but not too bad...
     
  13. Lumber-Jack

    Lumber-Jack
    Minister of Fire 2.
    NULL
    

    Dec 29, 2008
    2,007
    938
    Loc:
    Beautiful British Columbia
    OK, so I've got some wood that smells like pine, has cracking on the ends, and is kind of heavy, but not real heavy, and when I bang two pieces together it sort of goes clunk! clunk! What would the moisture content be with wood like that?
     
    Backwoods Savage likes this.
  14. ArsenalDon

    ArsenalDon
    Minister of Fire 2.
    NULL
    

    Dec 16, 2012
    752
    192
    Loc:
    Meadow Valley, CA
    Pine constantly amazes me at how fast it dries out. I got a cord of ponderosa a month ago...split it immediately and stacked it. A few of the thinner splits are already about 27%. Crazy fast drying wood.
     
  15. BobUrban

    BobUrban
    Minister of Fire 2.
    NULL
    

    Jul 24, 2010
    1,922
    1,133
    Loc:
    Central Michigan
    When the end cracks are wide it says, "wet on the inside" - as they close back up your wood is getting dry through and through. Wood that has been seasoning for years will show checking but no where near as prominant as wood that has been seasoning for 6 months.
     
  16. PapaDave

    PapaDave
    Minister of Fire 2.
    NULL
    

    Feb 23, 2008
    5,740
    2,221
    Loc:
    Northern MI - in the mitten
    27.67352%.
    Let it sit for another couple days and if it IS pine, you're gooder to go.;)
    Joking, of course. Needs at least another week. hehehe
     
  17. Lumber-Jack

    Lumber-Jack
    Minister of Fire 2.
    NULL
    

    Dec 29, 2008
    2,007
    938
    Loc:
    Beautiful British Columbia
    WOW! so that sniff and bang method really is very accurate. Guess I'll throw my moisture meter away, because it's telling me something totally different. ;)
     
    Backwoods Savage and PapaDave like this.
  18. Wood Heat Stoves

    Wood Heat Stoves
    Minister of Fire 2.
    NULL
    

    Jun 12, 2009
    1,905
    14
    Loc:
    Nevada City, California
    Here in California, it's so hot and dry that a soft wood like Pine will season in a Summer (about 4 mo) if it's split and stacked, Oak a year. Other parts of the country that are more humid can take a lot longer. I can feel the difference in weight between the unseasoned stack and the seasoned stack of the same type of wood just by picking it up. The proper way to measure moisture is to split the wood and stick a moisture meter into it but not everyone has one. I make sure I've seasoned it long enough before I even try to burn it and then I mostly sort it because some pieces get wet from rain or snow seeping in.
     
  19. PapaDave

    PapaDave
    Minister of Fire 2.
    NULL
    

    Feb 23, 2008
    5,740
    2,221
    Loc:
    Northern MI - in the mitten
    Man, I wish I could pick up a stack of wood.
    Filling the shed would be sooooo much easier.==c
     
  20. HDRock

    HDRock
    Minister of Fire 2.
    NULL
    

    Oct 25, 2012
    2,239
    859
    Loc:
    Grand Blanc, Mi
    Check out this thread Played with my moisture meter today
     
  21. Backwoods Savage

    Backwoods Savage
    Minister of Fire 2.
    NULL
    

    Feb 14, 2007
    27,815
    7,368
    Loc:
    Michigan
    Here in humid Michigan pine can dry pretty fast too. I cut two large limbs off a white pine in early December. These limbs came down in a July windstorm. The wood was all extremely dry and right now they are being burned for boiling maple sap.
     
    Wood Heat Stoves likes this.
  22. Wood Heat Stoves

    Wood Heat Stoves
    Minister of Fire 2.
    NULL
    

    Jun 12, 2009
    1,905
    14
    Loc:
    Nevada City, California
    It really helps dry the wood faster, too. I just pick up the stack and move it around so it stays in the sun all day. It's good to be strong. ::-)
     
    PapaDave likes this.

Share This Page