Moisture meter question

[Jason White]

Can anybody recommend a fairly inexpensive wood moisture meter of reasonable quality?

Also, what's a good moisture percentage for Eastern White Pine that has been air-dried?

Jason

[Bill Davis]

Not quite sure what you mean by "good". The air dried moisture content (MC) of wood depends on the average relative humidity in which it was stored while drying. If the RH was 80-90% the MC should be in the 15-22% range. On the other hand with a RH of 40-60% expect a MC of 7-12%.

On the topic of a meter, I have one which I would not be too excited about recommending though it's OK. Its biggest advantage was the price ($99). It is an Extech 407777. It was sent in the the factory for a problem but was returned with no improvement with respect to the original problem. I use it only as a relative indicator. Someday maybe I'll get a more reliable one. WoodWeb is a good source of info here (http://www.woodweb.com/cgi-bin/search/search.cgi?Realm=All&Terms=moisture+meters). Lots of stuff to read.

[Chris Friesen]

One classic basic moisture meter is the "mini ligno", but there are others. I have the "Timber check moisture meter", mostly because they carry it at Lee Valley.

I tried a cheap one, but the pins snapped off within a day.

[Curt Harms]

that is air dried. I recall sappy woods need to be heated to about 160 degrees to "set the sap" so it didn't continue to weep. Myth or fact, I'm not certain. I doubt white pine from the Colonial era was kiln dried.

[James G. McQueen]

Air dried moisture content will vary greatly depending on where you live. I live between Lake Erie and Lake Ontario. Moisture content here is consistantly between 12% to 14%. I see your in Boston so I will assume your relative humidity is high from the Atlantic influence. Thus higher moisture content.

If you were in the Midwest or Arizona your moisture content would be considerable lower due to less moisture in the air.

Check out Wagner moisture meters. They are surface meters and have no pins thus no holes. They are not affected by temperature like the pin types. A little more pricey but worth the extra cost.

[Scott T Smith]

that is air dried. I recall sappy woods need to be heated to about 160 degrees to "set the sap" so it didn't continue to weep. Myth or fact, I'm not certain. I doubt white pine from the Colonial era was kiln dried.


Curt - I own and operate a kiln and sawmill, and it is a "fact" that sappy woods such as pine may continue to weep if the pitch is not "set". Typically a kiln operator will take the load to 160F at the end to crystalize and set the pitch.

Jason - James's post is spot on re the EMC of air dried lumber. Most places it equalizes out around 12% - 16% when stored outdoors. It will continue to dry (and shrink) after you bring it inside, and should ultimately equalized out to around 8% (give or take a percent or two) depending upon the RH inside the home.

I'm not familiar with any of the inexpensive meters; most of the professional kiln operators use Delmhorst models; I have three of them ranging in price from a few hundred to a few thousand dollars. I also have an Merlin RF type meter that I like a lot, but it's around $400.00. Note that there are several different Merlin models to choose from.

[Rick Fisher]

I just ordered a Timber Check meter tonight from Lee Valley.. I liked the idea of it being tough..

I used to sell Delmhorst meters.. Very high quality.. Thought about getting one, just couldnt justify the expense for a hobby .. lol...

The Delmhorst are built like the old Motorola phones.. you can toss em around and they dont care.. The J series was cheap.. not popular.. The popular seller was orange, about $500.00

[John Thompson]

I have had the pin style Timber-check for years and it's good for the price. I use it at my supplier when chosing lumber. I use a Wagner at my shop after I have brought it home for acclimation. If necessary I could get away with the Timber-check there also so I think it would be a good choice for a good quality but less expensive model.

BTW... most meters are set for one variety of wood but you should get a conversion chart with your meter to allow you to convert to the wood you have. For instance my Wagner is dialed in for Doug Fir. If I get a 14% reading on QSWO I use my chart will tell me I actually have 10% moisture for white oak. The chart should list about all the hard-wood species.

Good luck...

[Jason White]

What I mean by "good" is:

How much moisture content is acceptable before I start making furniture out of it?

If I understand Scott correctly, it should be around 8%.

Jason


Not quite sure what you mean by "good". The air dried moisture content (MC) of wood depends on the average relative humidity in which it was stored while drying. If the RH was 80-90% the MC should be in the 15-22% range. On the other hand with a RH of 40-60% expect a MC of 7-12%.

On the topic of a meter, I have one which I would not be too excited about recommending though it's OK. Its biggest advantage was the price ($99). It is an Extech 407777. It was sent in the the factory for a problem but was returned with no improvement with respect to the original problem. I use it only as a relative indicator. Someday maybe I'll get a more reliable one. WoodWeb is a good source of info here (http://www.woodweb.com/cgi-bin/search/search.cgi?Realm=All&Terms=moisture+meters). Lots of stuff to read.

[Jason White]

Scott, short of taking the boards to a kiln -- is there any way I can set some of the sap using a space heater or other means?

Jason


Curt - I own and operate a kiln and sawmill, and it is a "fact" that sappy woods such as pine may continue to weep if the pitch is not "set". Typically a kiln operator will take the load to 160F at the end to crystalize and set the pitch.

Jason - James's post is spot on re the EMC of air dried lumber. Most places it equalizes out around 12% - 16% when stored outdoors. It will continue to dry (and shrink) after you bring it inside, and should ultimately equalized out to around 8% (give or take a percent or two) depending upon the RH inside the home.

I'm not familiar with any of the inexpensive meters; most of the professional kiln operators use Delmhorst models; I have three of them ranging in price from a few hundred to a few thousand dollars. I also have an Merlin RF type meter that I like a lot, but it's around $400.00. Note that there are several different Merlin models to choose from.

[Lee Schierer]

My Lignotech Mini Ligno says that the pine 2 x 4 that has been in my shop for a year is reading 8% MC. The air dried and kiln dried cherry is currently reading 7%.

[John Downey]

I have the one LV sells too, its a handy meter and affordable. I did find the pins a little soft for pushing into hardwoods, I'll typically use a couple finish nails and just use the pins as contacts on the nails.

[Scott T Smith]

What I mean by "good" is:

How much moisture content is acceptable before I start making furniture out of it?

If I understand Scott correctly, it should be around 8%.

Jason


Jason, generally speaking less than 10% is what is targeted by kiln operators, with an ideal range of 6% - 8%.

[Scott T Smith]

Scott, short of taking the boards to a kiln -- is there any way I can set some of the sap using a space heater or other means?

Jason


Jason, if it were the hot summer (and you lived someplace that got pretty warm) simply placing the boards up in an attic for a day or two would probably get them close enough to work for your needs, as most attics exceed 130- 140 in the summer.

If you could build some type of "tent" structure, using an insulating material such as tekfoil, and have a heat source inside you could do it yourself.

[Rob Holcomb]

Air dried moisture content will vary greatly depending on where you live. I live between Lake Erie and Lake Ontario. Moisture content here is consistantly between 12% to 14%. I see your in Boston so I will assume your relative humidity is high from the Atlantic influence. Thus higher moisture content.

If you were in the Midwest or Arizona your moisture content would be considerable lower due to less moisture in the air.

Check out Wagner moisture meters. They are surface meters and have no pins thus no holes. They are not affected by temperature like the pin types. A little more pricey but worth the extra cost.

I live about 50 miles East of Lake Erie in Southwestern NY and I too have consistent moisture readings of 12%-14%. I buy all of my wood rough cut from a local mill and it's kiln dried to 8% and then stacked in a pole building. It acclimates back up to the readings I mentioned. Due to the area where I live, I'll never see percentages below 12%. If I waited until it reached 8% to make a furniture piece, I'd have a shop full of tools that would yet to be used.