# Wet vs. Dry? Knowing when to start working the wood - Using 2-Pin Moisture Meters (1-12-2007)



## decoustudio (May 4, 2006)

I don't have time to do this topic full justice this morning, but I was going through receipts getting ready for taxes, and I found my receipt for the wood pin moisture meter I bought in 2006.

This was my first attempt at reading moisture in wood, but since I was self drying 2" thick white oak in a home built dehumidifcation drying system this summer, I wanted to know the results of the drying process.

I have hopes of writing up the self-drying procedures as a full article, so maybe I can get back to that at some point. Too many ideas to write up, too little time for unpaid manhours, if you know what I mean.

I will give more information on this topic in the coming days, but I wanted to state as soon as I thought of it that I purchased a Harbor Freight 2-Pin Moisture Meter, item number 2757-2VGA for $19.99, and another $7.99 for shipping.

This made it quite a bit less expensive than other brand names, and since I don't run a flush-with-cash operation here, I went with "cheaper." I have had a lot of fun using it, checking on moisture content before I do any work nowadays.

I have to be sort of careful with the meter, as it isn't built for hard use, as I am sure other brands are more suited for. But, for the $27.98 I have invested in it, I am happy with it.

In just a couple of seconds, I can insert the two pins, hit the "red" button and read where the light is located. I take several measurements to confirm the reading, and find some interesting results depending on where I read the moisture, but whenever I come back to a spot I have already checked, the reading is always the same, meaning that it is consistent and repeatable, and that works for me.

To do joinery in wood that has more than a 10% moisture content is just "ripe" with trouble, as mortises and tenons will shrink more as they continue to dry more over time.

So, to avoid the possibility of irrate customer calls, and embarrasing explainations of what went wrong, I try really hard to make my joinery last. I keep the tolerances of the joints perfectly snug when the joint is new, using the right glues, and pegging tenons with either screws, nails, wood dowels, or square wood pegs (my preference for appearance).

However, none of this diligence will help a joint where the wood drying process continues on after the piece has been delivered, and a tenon gets loose. This has not happened to me yet, but I am diligent to avoid it happening if I can help it. The Moisture Meter helps give me confidence in my process and the materials I am using.

I use the Moisture Meter to check the dryness of my wood before doing any critical operations (i.e. squaring all sides of a board, or starting joinery). If it is too wet, back in the dehumification chamber, and a few days, or weeks later, I try again.

I prefer to see it drop down in the 7-9% range, as I don't seem to have any trouble with additional cupping, bowing, twisting, or shrinkage of parts after they are completed at that moisture range. However, I have tried to work with 12%, 16%, 20%, 24%, and 30% moisture content on scrap parts in white oak just to experiment with what would happen. The results were unsatisfactory until I used wood below 10% moisture.

I think for low-budget lumberjocks that are playing around with air-dried wood, or buying wood from suppliers that don't confirm the moisture content with you before your purchase, this little $30 dollar tool will be of some help and value to them.

It is also fun to use. Oh, yea, there is another item of the "you must be a lumberjock list…."

More later as I promised, back to the receipt stack. I'm sure there are many of you that have moisture meters, or have wondered about getting one, so I decided to get this started now, as it will be helpful to the rest of the group.
Mark DeCou
www.decoustudio.com


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## Obi (Oct 19, 2006)

My friend that had me build his kitchen cabinets (My best pimp) saw a cen-tech moisture meter at Harbor Freight for about $8.00 and bought it for me, thinking it was "cute". I stuck his bench in his garage… nothing. I stuck my finger… 24 I stuck the tree in his front yard off the scale. Great item for $8.00 And you're right, knowing the moisture content is very valuable when it comes to working with wood when you don't know the moisture content. NOTHING is worse than working with wet wood and have your beautiful project split when it's sitting in a customer's house in the living room where it's warmest, and everyone can see it.

Next time I'm at his house I'll take pics of the tree house I built in his front yard.


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## scottb (Jul 21, 2006)

Only 24% Obi… must be drier in Calif. I thought that people were mostly water 75% or greater?!


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## Chipncut (Aug 18, 2006)

*Obi must be a well callused individual.*


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## Obi (Oct 19, 2006)

try it your self… on the outside you aren't as wet as you are on the inside … kinda like lumber


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## Don (Dec 18, 2006)

Mark, thanks for this. I must confess, I've ignored this subject up 'til now.

My reasons for doing so is that Melbourne is into the tenth year of a drought and everything is bone dry. Also, I usually purchase lumber that has been kiln dried, or properly air dried. (I prefer the latter.)

I've been fortunate so far. To my knowledge, none of my work has self destructed.

You make reference to your "dehumidifier". Can you tell us more?


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## Karson (May 9, 2006)

Mark: Do you know what is the stable moisture content of Kansas. In New Jersey where I lived it was about 15%. A board out of the weather would stabalize at around that number. The wood that I stored in my barn was 15% on the first floor but in the attic where there was a metal roof and I used to store hay, the wood would get to 7%. It would get about 130 deg in there in the summer.

I've not had any work self destruct because of the 15% figure. I tend to make everything with styles and rails and raised panels which minimizes wood movement.

I take it back. I did some cross glueing (which is a no-no) for a small storage box and it did self destruct. But it was probably a matter of bad construction techniques as anything else.

I just tested some of the wood in my workshop and its running about 11%. This would be on wood that I brought from New Jersey that was a combo of 7% and 15% wood. They are all mixed together now. Some cherry that I got from a barn at the sawmill that is all air-dried and under cover tested out at 11 - 13%. I was going to test the wood that is in my house, but failed to bring in the moisture meter. I own two of them a Lignomat pin meter and a Wagner pinless meter. I've not seen the Wagner since the move that was why I bought the Lignomat. So when I find it I can compare the two meters to see how they compare. The lignomat has a slide hammer that allows you to drive pins about 1" into the wood to get internal readings. I've not tried that yet.


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## oscorner (Aug 7, 2006)

I bought one of the Harbor Freight meters and was presently surprised that my two year air dried white oak was around 8% moisture content. Not bad for my first time at riving and drying wood, eh?


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## bbrooks (Jan 3, 2007)

I have been thinking of buying a moisture meter as well, but have been debating between the pin model and the non-pin model.

Based on the price, the Harbor Freight sounds great. Does it give you an actual percent, or just a red light in a specific range?

What do the others think, pin or non-pin model?


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## Obi (Oct 19, 2006)

It is numbered from 1 to 35


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## decoustudio (May 4, 2006)

Hey folks: like I said in my first sentence of this article, I didn't really have the time to finish up the information in a manner that the topic deserves. I have been reading all of your questions, and needs for more information, and I will be trying to round up all of my supporting information, and personal experience to get the article into a format where it better answers the type of questions we all want to know. The same questions I had before I decided to buy my moisture meter. Remember, the Harbor Freight one is cheap, and that helps with the decision to push forward with getting one, even in the darkness of insufficient information.

I screwed up a piece of my latest project yesterday, so I am scrambling to start over on a piece of it, and so I really need to get back to the shop now. (more on that later, with photos, stay tuned).

sorry,
Mark


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## decoustudio (May 4, 2006)

Karson: I have been pondering your first question for a couple of weeks. Can you do me a favor, and check the moisture content of something that has been in your house for several years. For instance, the back of a kitchen cabinet drawer, or a dresser drawer side. Somewhere that won't hurt to have 2-pin holes. If you can do that, then give me the reading you get, and that will help me answer your question about moisture content between different geographic regions. There are many of you out there that live on the coasts, and the moisture is different for sure. What is most important, is the moisture content in the home that the furniture sits in. For instance, my 6-year old kitchen cabinets drawer sides read 7% moisture content.


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## Karson (May 9, 2006)

Mark:

Here is what I found out.

Walnut outside for 2 years under a plastic sheet, No visable water on the wood. End 14, side 15
Walnut inside barn, only heated when I'm working there and only to about 55 degrees Only had maybe 15 - 20 heating days this winter. Inside barn for 2 years. Inside NJ barn for 5+ years. End 8.7 Side 7.8 
My meter (Lignomat) only gives deciminal reading when under 10%.
Oak cabinet face frame in kitchen 5.2
Pine shelving around my computer, I said Ponderosa Pine but I don't know 4.8 If Lodgepole pine it was 4.2, Southern yellow pine 2.7. It's pine I'm sure but what kind. I can't believe its Southern Yellow. You'd alnost have to bake it in an oven to get it to 2.7.
Oak table thats posted in projects as Table for my Son is 8.9

If I can give any additional info let me know.

Karson


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## bbrooks (Jan 3, 2007)

Nice and dry wood Karson. I have ordered an inexpensive moisture meter through Amazon, so I will be testing it out soon. I am almost afraid to think what my wood in the shop may be, since it has been there only a few months at most.


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## Dollarbill (Jan 26, 2007)

I do a lot of work with wood that is 15% (Ligno $130) and it turns out fine. But this is South Louisiana. Low humidity here in winter is 75%.

I only work in the winter because I spend my summers in Russia but the humidity in LA in summer is average 95%.

Bill


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## bbrooks (Jan 3, 2007)

Has anyone tried the no-pin models? I am just wondering if the accuracy is better with the pins or not. I do like the thought of no pin holes, but the cost is a bear.


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## Karson (May 9, 2006)

Bill:

I've used the pinless model. In fact I own one. I just haven't found it in 2 years since I moved. So I bought a pin version figuring that when I find the other one then I'll be able to do a comparason.

So to answer your question. I own a Wagner and it is suppose to check into the middle of a 1" board. It seemed to work fine. and I guess it was accurate because it gave values that I find on my pin version under similiar conditions.


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## bbrooks (Jan 3, 2007)

That is good to know Karson. Another of those items for my want list.


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## Karson (May 9, 2006)

I developed a spreadsheet that calculate wood movement for 120+ species of wood. It is an Excel spreadsheet. You enter the anticipated low value you would expect in furniture use and the anticipated high value that you would expect.

You also enter the wood species number from an included chart (US Government Wood Movement chart) and the current moisture content.

Then you give it the wood width and it will calculate the min and max size for that piece of wood.

If you want to try it out and see what needs to be improved send me an e-mail with the current e-mail address and I'll send it to you.

It works with Microsoft Excell and possable any other versions that read Excel files.


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## bbrooks (Jan 3, 2007)

I received my inexpensive moisture meter. So far, the wood I have tested is reading less than 10%, which seems strange to me since I have only had it a few months. I will test some other pieces to see if I get different readings. Maybe find a branch to trim off a tree just to see…


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