If I'm not mistaken there are several threads regarding moisture meters on LJ.
Which meter is correct?
I recently built a cellarette from sapele and had some angst about moisture content.
When I brought the board in, I measured the MC at 18" intervals and noted the MC in chalk at each point. As I recall, the capacitance meter read in the 12% range and the pin meter read less than 6%, which is its lowest reading.
I measured every other day for 2 weeks and there was little change. The basement is dehumidified and the RH was held at 40%. I tried weighing and drying a piece in a small microwave, but the oven died in the process. The build went just fine and there were no noticeable dimensional changes in the 3 months it sat in the basement.
Now, I have 2 more pieces of very nice sapele and find the same issue. The capacitance meter is showing 10% (corrected for species) and the pin meter is<6%.
The capacitance meter is a Wagner L609 and the pin meter is a PSI MD-2G, which they no longer list.
Anyone have any idea which to believe?
When I brought the board in, I measured the MC at 18" intervals and noted the MC in chalk at each point. As I recall, the capacitance meter read in the 12% range and the pin meter read less than 6%, which is its lowest reading.
I measured every other day for 2 weeks and there was little change. The basement is dehumidified and the RH was held at 40%. I tried weighing and drying a piece in a small microwave, but the oven died in the process. The build went just fine and there were no noticeable dimensional changes in the 3 months it sat in the basement.
Now, I have 2 more pieces of very nice sapele and find the same issue. The capacitance meter is showing 10% (corrected for species) and the pin meter is<6%.
The capacitance meter is a Wagner L609 and the pin meter is a PSI MD-2G, which they no longer list.
Anyone have any idea which to believe?
1 - 10 of 10 Posts
Best way to find out is to measure and then dry out a piece in the oven and see which one is closest.
I have both a cheap pinned and a cheap pinless meter and with mine, the pinned meter seems to be the most consistent. When I first got it I calibrated the pinless meter with a freshly cut wet piece and dried it out and the pinless meter seem to match pretty closely through out the rage of MC what the weight indicated as I tested it intermittently through the range. I never did that with the pinless meter. I used a microwave for that but didn't try to go below about 12-15%. It needs a certain amount of water in the oven or you can damage the oven. Below that, you should put a cup with a little water in it in with it to make sure it is not too dry for the microwave. Of course the official way to do that is in a regular oven.
Anyway, I say that below 12% is probably good enough, especially if it will be in a climate controlled space.
I have both a cheap pinned and a cheap pinless meter and with mine, the pinned meter seems to be the most consistent. When I first got it I calibrated the pinless meter with a freshly cut wet piece and dried it out and the pinless meter seem to match pretty closely through out the rage of MC what the weight indicated as I tested it intermittently through the range. I never did that with the pinless meter. I used a microwave for that but didn't try to go below about 12-15%. It needs a certain amount of water in the oven or you can damage the oven. Below that, you should put a cup with a little water in it in with it to make sure it is not too dry for the microwave. Of course the official way to do that is in a regular oven.
Anyway, I say that below 12% is probably good enough, especially if it will be in a climate controlled space.
OK, update !
I pulled a piece of 8/4 sapele left from last year's project that has been in the 40-45% RH environment.
It measures the same as the new pieces. I also measured some other species; cherry, walnut that are 10 years old and got similar readings. A 100 year old piece of white oak showed 9%, and a 180 year old piece of yellow pine showed 12%.
conclusion - both meters need to go in the trash.
I pulled a piece of 8/4 sapele left from last year's project that has been in the 40-45% RH environment.
It measures the same as the new pieces. I also measured some other species; cherry, walnut that are 10 years old and got similar readings. A 100 year old piece of white oak showed 9%, and a 180 year old piece of yellow pine showed 12%.
conclusion - both meters need to go in the trash.
After all this which type/which brand/model of MM does one rely on?OK, update !
I pulled a piece of 8/4 sapele left from last year s project that has been in the 40-45% RH environment.
It measures the same as the new pieces. I also measured some other species; cherry, walnut that are 10 years old and got similar readings. A 100 year old piece of white oak showed 9%, and a 180 year old piece of yellow pine showed 12%.
conclusion - both meters need to go in the trash.
- Carey Mitchell
Did you try on something you know is pretty wet?
BTW, my pinless meter has to be recalibrated every so often. When I start getting odd readings I know it needs to be recalibrated. Temperature is one factor that affects it.
BTW, my pinless meter has to be recalibrated every so often. When I start getting odd readings I know it needs to be recalibrated. Temperature is one factor that affects it.
Carey,
This may not help but, I recently built a trestle table out of IPE (35% moisture content). I just built it so the joints would allow for it to dry out. It is an out door table in s/w fla (ie very humid) it is now 16/17% moisture content now.
I know you do very fine work. I'm just suggesting to allow for wood movement and drying out over time.
I'd like to see what you are making.
This may not help but, I recently built a trestle table out of IPE (35% moisture content). I just built it so the joints would allow for it to dry out. It is an out door table in s/w fla (ie very humid) it is now 16/17% moisture content now.
I know you do very fine work. I'm just suggesting to allow for wood movement and drying out over time.
I'd like to see what you are making.
OK - the final word(s).
I cut a 2×2" piece form the end of one of the boards, weighed it to the nearest 0.001g, and placed it under a heat lamp for 3 days, the surface temp reaching about 170 degrees.
CONCLUSIONS:
1. sapele gives up moisture slowly, compared to other woods.
2. pre-heating measurements were 6%* and 12% (corrected for species) with the pin and capacitance meters, respectively. Weighed 4x per day.
3. At constant weight, indicating that all moisture that could be driven out was gone, the MC calculated to 7.8%.
4. The pin meter showed 6%. The Wagner pinless meter showed 7% remaiining.
5. so, the Wagner meter is unreliable. The pin meter is not far off.
6. I know some of the top people at Wagner from my former business experience and will be reaching out to them for an explanation.
I cut a 2×2" piece form the end of one of the boards, weighed it to the nearest 0.001g, and placed it under a heat lamp for 3 days, the surface temp reaching about 170 degrees.
CONCLUSIONS:
1. sapele gives up moisture slowly, compared to other woods.
2. pre-heating measurements were 6%* and 12% (corrected for species) with the pin and capacitance meters, respectively. Weighed 4x per day.
3. At constant weight, indicating that all moisture that could be driven out was gone, the MC calculated to 7.8%.
4. The pin meter showed 6%. The Wagner pinless meter showed 7% remaiining.
5. so, the Wagner meter is unreliable. The pin meter is not far off.
6. I know some of the top people at Wagner from my former business experience and will be reaching out to them for an explanation.
- - I misread the pin meter by looking down at it; looking from the front side, it actully read 6%.
Maybe I'm misunderstanding something.OK - the final word(s).
I cut a 2×2" piece form the end of one of the boards, weighed it to the nearest 0.001g, and placed it under a heat lamp for 3 days, the surface temp reaching about 170 degrees.
CONCLUSIONS:
1. sapele gives up moisture slowly, compared to other woods.
2. pre-heating measurements were 6%* and 12% (corrected for species) with the pin and capacitance meters, respectively. Weighed 4x per day.
3. At constant weight, indicating that all moisture that could be driven out was gone, the MC calculated to 7.8%.
4. The pin meter showed 6%. The Wagner pinless meter showed 7% remaiining.
5. so, the Wagner meter is unreliable. The pin meter is not far off.
6. I know some of the top people at Wagner from my former business experience and will be reaching out to them for an explanation.
- - I misread the pin meter by looking down at it; looking from the front side, it actully read 6%.
- Carey Mitchell
The pin meter read 6% both before and after heating? Even though the board lost weight between those measurements? (Assuming the weight loss was because of moisture loss)
And you're saying the pin meter is the accurate one?
Oops, I could have phrased it better. The pin meter did read 6%, but that is the lowest it reads. Good enough for me.OK - the final word(s).
I cut a 2×2" piece form the end of one of the boards, weighed it to the nearest 0.001g, and placed it under a heat lamp for 3 days, the surface temp reaching about 170 degrees.
CONCLUSIONS:
1. sapele gives up moisture slowly, compared to other woods.
2. pre-heating measurements were 6%* and 12% (corrected for species) with the pin and capacitance meters, respectively. Weighed 4x per day.
3. At constant weight, indicating that all moisture that could be driven out was gone, the MC calculated to 7.8%.
4. The pin meter showed 6%. The Wagner pinless meter showed 7% remaiining.
5. so, the Wagner meter is unreliable. The pin meter is not far off.
6. I know some of the top people at Wagner from my former business experience and will be reaching out to them for an explanation.
- - I misread the pin meter by looking down at it; looking from the front side, it actully read 6%.
- Carey Mitchell
Maybe I m misunderstanding something.
The pin meter read 6% both before and after heating? Even though the board lost weight between those measurements? (Assuming the weight loss was because of moisture loss)
And you re saying the pin meter is the accurate one?
- Tony1212
1 - 10 of 10 Posts
- This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
LumberJocks Woodworking Forum
A forum community dedicated to professional woodworkers and enthusiasts. Come join the discussion about shop safety, wood, carpentry, lumber, finishing, tools, machinery, woodworking related topics, styles, scales, reviews, accessories, classifieds, and more!
Full Forum Listing
Top Contributors this Month
View All
bandit571
156 Replies
Desert_Woodworker
141 Replies
JackDuren
72 Replies
Recommended Communities
