Author Topic: Moisture meter  (Read 6163 times)

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Offline Mac43560

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Moisture meter
« on: April 12, 2016, 02:54:10 pm »
I have an osage stave I acquired that was cut from stump to stave last month and I checked my MC and the machine said 13%.  My spider sense tingled so I measured it and weighed it and my rough calculations were way different.   So I need an upgrade/ replace my moisture meter as I can't trust this one anymore. What kind do you all use?  What's my price range for some dependability?
I still going to measure it the hard way when I can but I don't always have the luxury.

Offline Pat B

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Re: Moisture meter
« Reply #1 on: April 12, 2016, 03:03:57 pm »
I don't use a moisture meter any more(I gave it away) but I don't build bows from wood that hasn't been off the stump for at least a year, preferably more.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline DC

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Re: Moisture meter
« Reply #2 on: April 12, 2016, 03:11:10 pm »
I bought a $10 kitchen scale. Weight it every day or so until it stops losing weight.
http://www.csgnetwork.com/emctablecalc.html  is handy.

Offline Mac43560

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Re: Moisture meter
« Reply #3 on: April 12, 2016, 03:39:16 pm »
I am also experimenting with drying staves in months instead of years without heat by manipulating the RH with a dehumidifier only during moisture recovery periods like night time.  The way I see it,  at least 8 hours a night the RH is too high to have a suitable equilibrium MC.  That's a third of a year.  Plus if your climate is like mine, two months out of the year it rains too much to lower the EMC.  It might raise the MC.  By manipulating RH during those times alone just to what's normal on average,  I figure that's five months less for every year.

Offline DC

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Re: Moisture meter
« Reply #4 on: April 12, 2016, 04:23:44 pm »
Build a box and put a lightbulb in it but be careful if you try to dry too fast it'll check. The moisture can only move through the wood so fast and each wood is different. You would be better off using this time to collect wood. By the time you have a stave ready to work you will have a stockpile of wood that is drying faster than you're using it. Then the drying time is a non-issue. Getting past the first few is tough. My first ones took too much set because they weren't dry. I just looked in my warm box yesterday and there are at least ten staves in there ready to go. All I have to do now is collect a new stave for every bow I make and I will always have a stave ready to go. I also have a few extra for giving to people that can't wait to get going :) :)

Offline George Tsoukalas

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Re: Moisture meter
« Reply #5 on: April 12, 2016, 04:43:17 pm »
Sounds about right for a surface reading, Mac.
Keep checking the belly wood as you work the stave into a bow.
Stop when you get a reading above 10% and let it "dry".
Be sure you seal the back of the bow, which to my mind should be heartwood, to prevent drying cracks.
I use the Mini Ligno.
Jawge
Set Happens!
If you ain't breakin' you ain't makin!

Offline wizardgoat

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Re: Moisture meter
« Reply #6 on: April 12, 2016, 04:51:37 pm »
Weigh your staves. When they stop losing weight for at least a week or so they are good to go.
A scale doesn't lie, a moisture meter isn't telling you the whole story.

Offline Mac43560

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Re: Moisture meter
« Reply #7 on: April 12, 2016, 05:11:50 pm »
Thanks George.  I'll keep weighing and shop around for the meter.  I just don't want to use heat over normal Temps.  Using my dehumidifier and kestrel I can keep the EMC constant instead of constantly chasing it.

Offline PlanB

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Re: Moisture meter
« Reply #8 on: April 12, 2016, 05:21:06 pm »
I stopped using my moisture meter, likewise, and just weigh it every day on a digital gram scale, and pencil the date and reading on the belly side. Pretty simple, and always works for me -- unlike the moisture meter.
I love it when a plan B comes together....

Offline jeffp51

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Re: Moisture meter
« Reply #9 on: April 12, 2016, 07:16:03 pm »
I have a humidifier to keep the moisture content up to a level that I don't fear it will explode on me.  According to the charts, I would be sitting at 6-7% max moisture content if I don't try to add water.  Anyone have some hickory you want to send me? >:D

Offline Emmet

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Re: Moisture meter
« Reply #10 on: April 12, 2016, 07:28:35 pm »
I have one I bought for $30 at the local box store.
Its see a lot of use and works well till it drops close to 5% that low it won't pick up anymore.
I have some staves 3 years old that will read 13% once I open them up. I just don't bend them till until  checking moister.
 It's always near by and I keep checking any time I work on one or before shooting sometimes. I consider mine to be as handy as a shop rag.

Offline bradsmith2010

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Re: Moisture meter
« Reply #11 on: April 12, 2016, 07:40:53 pm »
you can weigh your stave, but if the relative humidity is too high, it still may have too much moisture to make a good bow,, and would need to be placed in a dryer location,, and the opposite as well, if the relative humidity where the stave is stored is way to low,, the bow could break,, so a moisture meter can help in that way,, I had a bow explode this winter, I had it in a heated room,, of course it was not loosing any weight, but the moisture content of the bow was 6% or lower,, my meter will only go that low,, so my moisture meter gave me a clue not to keep bows in that room,, :)  it is not a necessary tool for sure,, but at times can be very helpful,, when you are roughing out a stave, the meter will give you a clue as to if the bow might check or not,, etc etc etc,,

mikekeswick

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Re: Moisture meter
« Reply #12 on: April 13, 2016, 02:42:00 am »
Moisture meter are notoriously inaccurate. Look at the price range available...why do the expensive ones cost so much? Also we need to know what the wood is doing in its center not the surface.
Feel will get you there. I only need to take a few shavings now to get a good idea on mc.

Offline Lumberman

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Re: Moisture meter
« Reply #13 on: April 13, 2016, 09:03:46 am »
RH being kept low will only get you so far, I kept the kiln the other day at 140 Fahrenheit and an RH of 15 that's with fans on em too and 2 out of 7 samples lost no moisture and the others lost 1% at most. Granted i was down to 7-10%, on the lower ones but it's just hard for me to imagine it fluctuating within a piece of wood very quickly with out some significant heat and humidity both being involved

Offline Mac43560

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Re: Moisture meter
« Reply #14 on: April 13, 2016, 09:45:26 am »
Yeah I have no delusions about that last 5% of the moisture leaving the wood quickly or easily.  But the bulk of it, you'd be surprised.   Around half the wood moisture is unbound in the wood anyway.  It's how nature cures wood and if you live out west, it does it exceptionally even in places with temperate climate and temperatures. And that's with diurnal changes in RH and some overnight recovery.  But I am taking weeks not days.