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Thread: Questions completing the drying process. Midwest climate, 2" walnut, multiple options

  1. #1

    Questions completing the drying process. Midwest climate, 2" walnut, multiple options

    I live in Indiana for geographical reference.
    Came across a decent lumber haul of about 200BDFT of walnut for dirt cheap.
    Most of it has been slabbed 2" thick (2 boards are 4" thick and I'm thinking they will never, ever dry up. lol), it was sawn and air dried outside since last summer and now sitting in my shop which is located in an unfinished garage (No HVAC, no humidity control, no drywall, etc.).

    3 Options here:

    1. Take it out back in my yard and correctly stack it in the through the spring/summer then bring it into my finished basement sometime in the fall/winter aka "heated season".
    2. Keep it stacked, stickered and weighted in my garage through the spring/summer then bring it into my finished basement sometime in the fall/winter aka "heated season".
    3. Bring it into my finished basement now and let it complete the drying process now.


    Which of these options is the most valid for completing the process properly. Thanks for the help!

  2. #2
    Join Date
    Feb 2008
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    E TN, near Knoxville
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    6,212
    Is your goal 9 or 10% moisture for furniture making?

    Perhaps you could measure the moisture content now to help decide.
    This partial chart might show what EMC you might expect for air dried lumber in your part of the country. If the moisture is 12-15% inside that's probably as dry as it's going to get outside or in the garage.

    mc_partial-chart.jpg

    A good pinless moisture meter should give an idea of the EMC but for an exact moisture you can use the oven dry method, even for thick stock. This involves cutting a small sample from the middle of one board. All you need is an inexpensive gram scale and an oven set to about 200F. Weigh first, heat for about 24hrs or until the weight no longer changes then calculate the moisture content. I use an old toaster oven and these tiny scales:

    https://www.amazon.com/gp/product/B0012LOQUQ
    https://www.amazon.com/gp/product/B002SC3LLS

    Another way if you have room is to stack and sticker it indoors and monitor the weight of one board over some months until it quits changing.

    This might be useful. It has the chart above, the oven dry method, and all about air drying.
    https://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr117.pdf

    JKJ

  3. #3
    Quote Originally Posted by John K Jordan View Post
    Is your goal 9 or 10% moisture for furniture making?

    Perhaps you could measure the moisture content now to help decide.
    This partial chart might show what EMC you might expect for air dried lumber in your part of the country. If the moisture is 12-15% inside that's probably as dry as it's going to get outside or in the garage.

    mc_partial-chart.jpg

    A good pinless moisture meter should give an idea of the EMC but for an exact moisture you can use the oven dry method, even for thick stock. This involves cutting a small sample from the middle of one board. All you need is an inexpensive gram scale and an oven set to about 200F. Weigh first, heat for about 24hrs or until the weight no longer changes then calculate the moisture content. I use an old toaster oven and these tiny scales:

    https://www.amazon.com/gp/product/B0012LOQUQ
    https://www.amazon.com/gp/product/B002SC3LLS

    Another way if you have room is to stack and sticker it indoors and monitor the weight of one board over some months until it quits changing.

    This might be useful. It has the chart above, the oven dry method, and all about air drying.
    https://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr117.pdf

    JKJ
    Thanks!
    Yes, it is all going to be for indoor projects such as furniture.
    I just ordered a pinned moisture meter last night which after what you said seems like I should have gone pinless. I don't usually buy lumber that needs all this attention so it would be tough to spend that much for a pinless....
    I really like the oven method and going to order one of those scales and give it try!

    If my EMC for where I live never drops below 12%, how do I go about getting the walnut down to 9-10%?

  4. #4
    Stable MC is what's important, so don't worry about shooting for a certain number. I would sticker it inside and record MC's on a monthly basis until it quits dropping.
    Do not cover it, or allow a fan to blow over it or allow sun to beat down thru a window. The thicker boards could take 2-3 more years (I figure 1 yr/ inch).

    The problem is going to be how similar is your shop environment to inside your house.

    You won't have this problem but for me its extreme because I live in a very humid area with huge humidity swings (60% daytime to 100% night). I store project lumber and parts in a climate controlled room bench room w/ stable temp/humidity & similar to house. I do the entire build in there. It makes a huge difference, especially for a piece like a dresser, or anything with drawers.

  5. #5
    Join Date
    Feb 2008
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    E TN, near Knoxville
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    Quote Originally Posted by Christopher Dawson View Post
    I just ordered a pinned moisture meter last night which after what you said seems like I should have gone pinless.
    ...
    If my EMC for where I live never drops below 12%, how do I go about getting the walnut down to 9-10%?
    Some people prefer the pin type, I like the pinless. I don't know if it matters. Neither will measure to the very center of the wood. This isn't as much problem as you might think except for very wet green wood which can have a significant moisture gradient from the sides to the middle. When the total moisture has been reduced a lot by air drying the moisture gradient is "flatter" through the middle especially for walnut (unlike some very hard/dense woods). The oven dry method is always accurate.

    To get the EMC down to 9-10% sticker it in a conditioned space like a house or air-conditioned/heated shop and let it air dry. You can run a dehumidifier in the room if the humidity is high. Or get someone with a kiln to dry it. Or move to Alberquerque.

    The commonly cited 1" per year plus 1 year rule of thumb for air drying has been widely debunked, but it is probably a better starting place than nothing. I find woods like cedar, sassafras, and soft maple to dry much quicker but woods like osage orange, white oak, and dogwood take considerably longer. Walnut is probably somewhere between these extremes. I cut some 3+" square ambrosia soft maple turning squares recently, anchorsealed the ends, and put them on my wire shelves to dry. In one month they were still pretty wet at 20-25% moisture. After three months they are down to 10%.

    I wrote this recently about testing an ebony purchase using the oven dry method. (For some reason the thread turned in to a "drying bowls with a microwave oven" discussion so ignore that.)
    https://sawmillcreek.org/showthread....ven-dry-method
    I used a thermocouple to monitor the temperature but that's not entirely necessary, just don't get it too hot! If the temperature is too low it will just take a lot longer. Walnut should not take as long as ebony.

    JKJ

  6. #6
    Quote Originally Posted by John K Jordan View Post
    The oven dry method is always accurate.

    To get the EMC down to 9-10% sticker it in a conditioned space like a house or air-conditioned/heated shop and let it air dry. You can run a dehumidifier in the room if the humidity is high. Or get someone with a kiln to dry it. Or move to Alberquerque.

    The commonly cited 1" per year plus 1 year rule of thumb for air drying has been widely debunked, but it is probably a better starting place than nothing. I find woods like cedar, sassafras, and soft maple to dry much quicker but woods like osage orange, white oak, and dogwood take considerably longer. Walnut is probably somewhere between these extremes. I cut some 3+" square ambrosia soft maple turning squares recently, anchorsealed the ends, and put them on my wire shelves to dry. In one month they were still pretty wet at 20-25% moisture. After three months they are down to 10%....
    JKJ
    As of right now, I have it stacked and stickered in my shop/garage. Will check with the moisture meter and do the oven drying method this weekend to determine the current content. If it's higher than I suspect will the offing of moisture into the shop affect my tools?

  7. #7
    Join Date
    Feb 2008
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    E TN, near Knoxville
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    Quote Originally Posted by Christopher Dawson View Post
    ...will the offing of moisture into the shop affect my tools?
    The way I understand it, whether moisture in the air will promote rusting on steel depends on the the dewpoint, the temperature at which moisture condenses out of the air. This dewpoint depends on both the humidity and the temperature (and to some extent the barometric pressure, I think). Water can condense quickly on cold tools brought into warm, humid air. I forget how to calculate it but you could look it up, perhaps monitor the humidity of the room with a gauge, run a dehumidifier if you are on the edge. I suspect you will have no problem if the wood is partially dried and the volume of the room is large relative to the amount of wood.

    My shop has heat and air so I don't worry about it even though I often have a bunch of fresh-cut sopping wet wood drying - the only time I use a dehumidifier is to dry honey that has a touch too much moisture!

    JKJ

  8. #8
    Wow you're quite the breadth of knowledge! Ha, I look into that. Wasn't going to spring for a dehumidifier but I may end up going with one and use it in the shop and once i bring the lumber inside.

    The oversized garage/shop has no HVAC but its about 700 SQ FT. I usually crack the back door and open the front to get a nice cross breeze going through so it should be alright. I guess we'll know everything turns orange!

    Thanks for all the help and suggestions. Really appreciate coming from a newbie such as I.

  9. #9
    Join Date
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    Toronto Ontario
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    Hi Christopher, choice # 3 is what I would do.

    It doesn't matter whether the wood is 12 % or 6 % now, what matters is that is at the same level as the final location for the furniture.

    For me, the basement is the same as the house so once my wood has reached basement equilibrium, that's the correct level of moisture.

    You might need a dehumidifier, however in my experience in Ontario, once I air dry over the winter it goes in the shop without issue...........Regards, Rod.

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