# Foolproof Moisture Content Assessment



## Battenkiller (Mar 2, 2010)

I don't trust moisture meters, never have. They are dependent entirely on industry established tables derived from the average resistivity of various wood species at various moisture contents.  These tables don't take into account the differing methods for determining and expressing moisture content in wood, nor do they differentiate between woods grown in different areas, between sapwood and heartwood, etc.  And heck, if you're new to all this, you probably aren't even sure of the species you are testing.  The very best of them (Delmhorst is the industry standard) work reasonably well in most situations and with a bit of experience, but a pro model is close to 5 bills with the proper electrodes.  Trusting your precious home (and maybe your lives) to the results of a $29 HF meter is pure folly AFAIC.  So how can a new burner know with 100% certainty how much water is really in his firewood?


I decided to develop an easy as pie method to get the moisture content of your firewood without a shadow of doubt.  The method involves a small saw, a cheap digital dietary scale and a microwave oven to dry the wood.


I took 13 samples of firewood from three different species, all having been subjected to different drying conditions.  Using a small bow saw or carpenter's saw (I used my band saw), cut a slice about 1" thick from the center of the split or round is question.  Use the center because that is likely to be the wettest part of the split.  Weigh the slice of wood on the kitchen scale (use the "gram" setting) and record this weight onto the wood slice with a magic marker.  I used a triple beam balance only because I was in the workshop.  Accuracy to tenths of a gram aren't really important because we used such a big slice to begin with.











Take the wood slice into the kitchen and put in on several paper towels on the bottom of the microwave.  Give 30 second blasts on high, rotating the slice in a new direction after each cycle.  Water will be removed very rapidly at first.  The microwave will get steamy inside for the first few cycles.  After about 10 cycles, start weighing the slice after every cycle.  Give it about a minute or two between cycles, and pay strict attention to how hot the wood is getting.  Soon it will slow down its weight loss and eventually it will stop losing weight.  Just like the folks using the scale for its original purpose.

Be very careful that you take your time with this or you will surely set your wood and microwave on fire.  If that happens, your wife may never let you do this again.  Plus, you will inadvertently remove at least some of the actual wood fiber content which will show your wood as having a slightly higher moisture content than it really had.  I had 13 samples to do, so I rushed and fried a few of the  the slices to some degree, but I don't think I really lost too much wood.  I'll be more careful the next time.










I did all of the slices on one day, then weighed them the following morning.  Most had actually gained a few grams of moisture, which is what I expected since even with the desert like conditions in a winter home, the air still has some moisture in it which the wood will reach equilibrium with.

When the wood stops decreasing in weight, it's time to re-weigh a final time and record the weight on the slice.  I cooked them all again until they stopped losing weight, then put them in a 215ºF oven for about 8 hours. I needed to be sure that the microwave would remove all of the water.  Most only lost a couple more grams of water after 8 hours in the oven (one lost nothing at all) confirming that the microwave drying methods works perfectly fine.  With a bit of attention to detail and patience, all you will need is the microwave to get a result accurate enough for this purpose.









The wet looking spots on this hickory slice are actually sugars that have boiled out of the end grain and dried there.  Has anyone ever tasted the sap that exudes from wet hickory splits?  Yummy!  Too bad no one taps these things for syrup.









Now, just take the difference between the wet weight and the dry weight (which is the total amount of water removed), then divide this difference by the oven-dry weight to get the final ratio of water removed to oven-dry weight.  Multiply by 100 to get the starting moisture content of the wood as it is most commonly expressed.

For example, the hickory round weighed 450 grams when I first cut it, and then 315 grams by the time all of the water was cooked out of it.  450g-315g=135g water removed.  135g/315g(oven-dry weight)=.429x100=42% MC. 


Here's the final spreadsheet for the little project.










After I was done with all of the slices, I took them - all 4 1/2 pounds of them - and put them right on top of a nice bed of red-hot coals.  Man, was _that_ interesting!


I only hope no one gets the idea to microwave their wet wood instead of getting it to dry in other ways.  For large scale drying in this manner, I would think one would need to use a _macro_wave instead. ;-)


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## PNWBurner (Mar 2, 2010)

Bravo!  Well done!

I especially like the steam (or is it smoke) in the second picture  :bug: 

Don't try this at home kids...

Seriously, I had considered sticking some splits in my oven on the low low setting overnight but this looks way more fun.


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## Nonprophet (Mar 2, 2010)

I'll give you an "A" for effort, but it's really not a new idea i.e. this is from the OSU extension service website: 

_"Weigh a small piece of firewood cut from the middle of a large piece. Record the weight in ounces. Dry the small piece overnight at 200 to 300 degrees in your oven. Weigh it again while it is still warm. The difference in weight is the weight of the water in the wood. Divide the weight of the water by the oven-dry weight in the wood to find the moisture content of your firewood. Wood is ready to burn when the moisture content is less than 20 percent." 
_
Simple, yet effective.

Regarding your disdain for moisture meters I really don't see it as a life or death situation, just trying to determine which of my wood is ready to burn and/or what drying methods seem to be working best.

I know a fair number of folks poo-poo moisture meters (i.e. if we knew what we were doing we wouldn't need one), but to me they're like a tire pressure gauge.  Sure, anyone can tell the difference between a 35 PSI tire and a 10 PSI tire, but what about the difference between a 35 PSI tire and a 28 PSI tire? Very few people can really tell just by looking and yet there's a big difference in tire wear and gas mileage.....And so it is with a moisture meter. Sure, I can tell the difference between 32% and 16%, but what I use a MM for is to tell the difference between 24% and 19%.


NP


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## skyline (Mar 2, 2010)

Battenkiller,

Well done. If I read that right it looks like 10 days was all you needed to drop your cherry from 50 to 30%. I don't know what your "inside" conditions are but clearly it moves the drying process right along. Let us know how long it takes to get to that 16-20% range, especially with the oak. 

I'll try to do something similar on my next experiment if I can keep from getting carried away with the microwave :ahhh: 
Still waiting for a scale that can live at the wood pile. 

In the mean time I'll keep weighing my pieces by the fan until eventually I get bored and then I'll dry them and weigh them to calculate what the real moisture content has been all along. But in 6 weeks on the fir I have lost what will be over 50% and over 93% on the alder in front of the fan. The neat thing is that the pieces away from the direct path of the fan are only about 6-7% less at this point suggesting that just a little bit of air movement maybe all that is necessary to accelerate the drying process. That is, by raising the temp just a few degrees, like an unheated garage or accessory building will lower the RH/EMC considerably to allow the fan to really drive the moisture out of the wood.

You seem like a good person to check with. I'm using 2500 as a multiplier for Kg of water lost to compute BTU added to my splits, based roughly on the following:
~2150 btu to boil 1 kg of water and 350 btu to raise 1 kg water from 60ºF to 212ºF 

Does this seem about right to you?

Also, thanks for showing me how to include the spread sheet on the forum!


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## DanCorcoran (Mar 2, 2010)

Battenkiller,

I'm assuming you didn't know this, but people don't tap hickory because the sap will cause large green warts on your tongue (it said so on the OSU extension service website).


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## Jags (Mar 2, 2010)

Very well done, but is this really as easy as "Pie"?

Common folks, we are talking about firewood, not the veneer needed to rehab a 600 year old painting frame.

I would venture to say that my $29 dollar meter does a fair job at giving me an ESTIMATE of the MC% in my FIREWOOD.

I really am impressed at the length that some will take to "accurately" measure the MC% of the firewood, but I will bet that yours doesn't burn any better than mine (yeah, even the stuff that was measured with a $29 meter).

This is in NO way intended to tick anybody off or demean the testing (it is actually a very well executed home test, bravo), but get it under 20% or 22% or 18% and light a fire underneath it (or on top of it if you swing that way  )


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## PNWBurner (Mar 2, 2010)

It would be very interesting to compare the indicated MC from a cheapie meter with the "known" MC derived through your oh so simple process.

I wonder how close it would be?


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## Battenkiller (Mar 2, 2010)

DanCorcoran said:
			
		

> Battenkiller,
> 
> I'm assuming you didn't know this, but people don't tap hickory because the sap will cause large green warts on your tongue (it said so on the OSU extension service website).



Yeah, but now that I'm covered with them, might as well keep licking the sap.


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## Battenkiller (Mar 3, 2010)

Jags said:
			
		

> Very well done, but is this really as easy as "Pie"?
> 
> Common folks, we are talking about firewood, not the veneer needed to rehab a 600 year old painting frame.
> 
> ...



Jags, this is the first time in about 25 years that I ever even had a clue what the MC of my firewood is.  I could care less, really.  I'm more of an intuitive burner.  I may pick it up, feel the heft, look at it, clank it around a bit, drop it on the cement floor, listen to it, smell it, toss it into the air and catch it with one hand to see how it feels and then toss it into the stove to see how it burns.  If it burns well, it's ready in my book.  If not, well, no real lasting harm done.  Rest assured, I never throw anything into my stove that doesn't burn at all.  Passed that stage a very long time ago.

That said, there are several of us here who plan on sharing data pertaining to wood drying rates in various conditions and using differing techniques.  I don't trust _any_ moisture meter to be that precise.  Wood scientists have been using the over-dry method for a hundred years or more, so I don't think I invented anything new.  Microwaving wood to dry it is also a well known technique to woodturners and carvers, so I make no claim on that either.  I may possibly be the first, however, to marry the ideas together in a quick, cheap and easy to perform test for MC in wood that can be done while your pasta is cooking.  I needed to come up with an easy way to get the exact MC at each stage of the game.  When comparing lots of data, repeatability in your measurements is crucial.  Many data sets look completely random (like when you look at a scatter plot), but then you run a regression analysis and you get a degree of linearity that may indicate something.  My hope is that we will find some intriguing correlations, but that might prove to be impossible if the instruments themselves are not precise.  The oven-dry method is both precise and accurate... and it's basically free.

Again, the only reason for developing this method is for data acquisition, not for determining if individual splits are "burn worthy". Would small differences in MC that are undetectable using a high quality moisture meter affect the burn in your stove?  Hell, I don't find all that much difference between the cherry I've been burning at 18% and the oven-dried wood I threw in my stove the other day.  Why would there be that much difference between 18% and even 25% MC in wood?  Folks say the difference is huge.  Well, then it is... for them.  I burned green ash (30-35% MC) for years, and I got my stove hot enough to burn right through the side baffle plates every 2-3 years.  How much hotter do you want to get it?


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## Tony H (Mar 3, 2010)

Nice testing can we call you Mr. Science now %-P  I got one of those cheap meters to play with it seems to give you an idea of moisture loss if you test and then retest the same wood, but to tell you the truth I really don't use it for anything more . Since it's been sitting inside not testing any wood since last fall I guess it was mostly a waste of money.


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## gzecc (Mar 3, 2010)

Batten, Have you had any family members witness this experiment? Is anyone considering an intervention?


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## mdphilps (Mar 3, 2010)

Battenkiller said:
			
		

> Now, just take the difference between the wet weight and the dry weight (which is the total amount of water removed), then divide this difference by the oven-dry weight to get the final ratio of water removed to oven-dry weight.  Multiply by 100 to get the starting moisture content of the wood as it is most commonly expressed.
> 
> For example, the hickory round weighed 450 grams when I first cut it, and then 315 grams by the time all of the water was cooked out of it.  450g-315g=135g water removed.  135g/315g(oven-dry weight)=.429x100=42% MC.



Battenkiller....Nice Job!!

But I'm a little confused by your MC calculation.  To find the original MC, wouldn't you take the "Water Removed" value and divide that by the wet weight, not the dry weight?

Therefore your example would be 135g/450g=.3 x100 = 30%MC

Example....if a bag of popcorn had 100 pieces in it and I ate 25 of them.....So I ate 25/100 = 25% of the bag
Not 25/75 = 33% of the bag

Please correct me if I'm wrong!
Matt


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## gyrfalcon (Mar 3, 2010)

Couple questions, Batten?

First, is that oak white or red oak?

Second, when your chart says it's X months old and XX days inside, what does that mean?

Does "inside" mean inside the heated part of your house?  And X months old means X months since it was split?

And where was it the rest of the time since it's been split?  It was stacked outside?

Does that mean of those two pieces of oak on your chart of the same 2 months age, one was brought inside right after it was split, and the other stayed outside for six weeks before being brought in for another two weeks?

If I'm reading that right, that seems like a mighty big drop in moisture content for six weeks sitting indoors compared to lingering outside in the NE winter.


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## Smokey_da_Bear (Mar 3, 2010)

mdphilps said:
			
		

> Battenkiller said:
> 
> 
> 
> ...


+1 That has me a little confused as well.

Nice test, but I think I would have started out by taking a reading of those wood splits with my moisture meter first as PNWBurner suggested, then you could have compared the values of your test against your moisture meter. That way you could at least confirm if your mistrust in those moisture meters is warranted or not.


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## Jags (Mar 3, 2010)

Battenkiller said:
			
		

> That said, there are several of us here who plan on sharing data pertaining to wood drying rates in various conditions and using differing techniques.
> 
> Again, the only reason for developing this method is for data acquisition, not for determining if individual splits are "burn worthy". Would small differences in MC that are undetectable using a high quality moisture meter affect the burn in your stove?



I got it!  This is more than just determining if the wood is seasoned and ready to be stove chow.  I can see how an "estimate" doesn't fit into this well.  Again, bravo.

(but you guys need better hobbies. :lol: )


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## Backwoods Savage (Mar 3, 2010)

It amazes me what lengths people go to in order to determine if the wood is ready to burn. I've burned wood for over 50 years and have never felt the need for moisture meters or any other method. When the wood is dry, it is ready to burn. Now you know my whole philosophy. If you don't know if your wood is dry or not, test it in the stove. The final fire is the ultimate judge of whether the wood is dry or wet or almost dry. It all goes back to the big fact; if you are going to burn wood, you need to do things right by getting your wood ahead of time so it has time to dry. If you are not willing to do this then in my book either you should not burn wood at all or you must be willing to put up with poor fires and dirty chimneys. You also must be willing to spend more on buying wood because if it is not ready to burn and you insist on burning it, you will burn more wood for the required heat. Summary: Keep it Simple, Sir. Cut your wood ahead of time and let Nature work in your favor. Time, wind and sunshine are firewood's friends.


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## Cutter (Mar 3, 2010)

I did a similar experiment a few months ago after some conflicting views here on the MC of green hedge and having to season for a year or more. I used a fresh green round that still had leaves on it. I removed the bark and cork cambium. I stuck the sample in an Estufa (which is an oven for baking wine into Maderia). I had weighed the sample in grams before and after. It was held at 130 degrees for three months. Then I ran it for three more months after which it lost only 5 more grams of weight out of the original 1835 grams. I determined that the green sample contained 25.5% moisture. Through the process I used a cheap Harbor Freight moisture meter and found that it was giving me readings almost exactly the same as what my weight measurements were telling me. 
  This told me to hang up the meter which was accurate to within a  percent or two. cut my hedge and worry very little about cutting and splitting in the spring and summer and burning it in the winter. The interior of hedge is so dense that very little moisture exists there.


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## Battenkiller (Mar 3, 2010)

mdphilps said:
			
		

> But I'm a little confused by your MC calculation.  To find the original MC, wouldn't you take the "Water Removed" value and divide that by the wet weight, not the dry weight?
> 
> Therefore your example would be 135g/450g=.3 x100 = 30%MC
> 
> ...



That's another way of expressing moisture content, and it is perfectly valid to use for your own purposes.  However, almost all scientific and technical writings - including tables of firewood MCs - use the water lost/oven-dry weight, so that is what I used.  Without going into a long explanation as to why, I am pretty sure that all moisture meters are calibrated for this method, so you really need to stick to the convention, even if sometimes it shows that you started out with green wood with a MC of over 200%.

I'd be pretty happy to say that my test 60 day cherry split was at 15% rather than at 18%, or even better, that the oak was at 27% MC (and therefore burnable) rather than the 36% MC the established method shows it to have.  Can't say my stove would agree with me, however.




			
				gryfalcon said:
			
		

> Couple questions, Batten?
> 
> First, is that oak white or red oak?
> 
> ...




Gryfalcon, the oak was some other kind of oak, not northern red, but very "red-oakey" looking and smelling.  Wood guy couldn't remember what they called it, but definitely not white oak.  He was kind of embarrassed that it was in there at all because the load was supposed to be straight hickory.  Can't always control the help, though.

The times in the "Age" column are the time since cutting and splitting.  My wood guy told me it was just cut and split from trees felled the day before he delivered it.  He told me it was "next year's wood".  No reason to say that if it wasn't true.  Most guys will say, "Yup, it's been cut down and seasoned for six months now, then we bucked it up and split it yesterday..."  Honesty is a refreshing change, and he knows that's what keeps me coming back for more.

So, yes, the wood that says "0" days was taken directly from the wood stored outside, seasoning in the winter air.  All times inside were spent within 3-4' of the stove (stove is hidden behind the wall of cherry in the photo) in my basement wood shop, at least some of the time with a fan (that big Jet air filtration unit in the photo) blowing over them.  The two splits at 60 days were placed on an old produce scale to see how much water they were losing.  I'd check them every day and watch as the weight just plummeted for the first several days, and then leveled out and almost came to a standstill.  

The split that I took the 60 day oak sample from weighed 13lbs, 15oz when I brought it into the shop and weighed 9lbs, 10oz when I cut the slice out of the center.  It lost 4lbs, 5oz. just sitting there on the scale, much of it during the coldest part of January when the inside RH was about 20% in my shop.  The 60 day cherry split weighed 7lbs, 12oz when I first placed it on the scale and was down to 5lbs, 4oz for a loss of 2lbs, 8oz, almost all of it during the first month.  Actually, after 1 month, I put that split back outside in an area protected from rain and snow, and it _picked up_ 3 oz. out there, even in the dry winter air.  It dropped it again when brought back inside for a couple of days. 

Yes, that is a phenomenal amount of water to lose, but that's even more compelling evidence that relative humidity and air movement are the principle players in seasoning... er, _drying _firewood.

Also, note that the hickory round seasoning outside in the cold air dropped just about as much in moisture content as a similar diameter split half, somewhat debunking the notion that splitting is absolutely necessary for seasoning.  I've always noticed this to be true, but rounds do ignite slower in the beginning, and burn slower and more evenly because of their compact mass.  They burn cleaner as well because less wood is exposed for pyrolysis at any given time, so I really like to use well dried rounds when possible.

The one confusing thing to me is the cherry from outside.  It still showed a MC of about 50% after three months outside, compared to the hickory (a much denser wood), which was already down to about 40% MC after only two months.  One possible explanation is that the cherry was a split I pulled at random from wood that I has brought in the night before.  Some of that wood was at the very bottom of the stack and was quite wet from snow and rain and poor circulation (stacked against a stone wall).  Maybe I pulled one of those.  That was one of the splits where I took slices from about 3" into each end as well as from the center.   The data shows that there was definitely a moisture gradient going on along the length, which could very likely be the result of the back end being up against the stone wall.  The photo shows the cherry as it sat outside.

The hickory, however, I took directly from near the top of the outside stack.  The photo shows this hickory the week before the test.  Notice how much more deeply checked the hickory is than the oak splits are.  Oak dries slower than anything in my experience.  BTW, can anyone positively ID the species of oak from the photo?




			
				Jags said:
			
		

> I got it!  This is more than just determining if the wood is seasoned and ready to be stove chow.  I can see how an "estimate" doesn't fit into this well.  Again, bravo.
> 
> (but you guys need better hobbies. :lol: )



Ha,ha!  Ya, guess we do.  But the trout opener is still a month away and I had all my flies tied ages ago.  Gotta do_ something_.


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## gyrfalcon (Mar 3, 2010)

Backwoods Savage said:
			
		

> It amazes me what lengths people go to in order to determine if the wood is ready to burn. I've burned wood for over 50 years and have never felt the need for moisture meters or any other method. When the wood is dry, it is ready to burn. Now you know my whole philosophy. If you don't know if your wood is dry or not, test it in the stove. The final fire is the ultimate judge of whether the wood is dry or wet or almost dry. It all goes back to the big fact; if you are going to burn wood, you need to do things right by getting your wood ahead of time so it has time to dry. If you are not willing to do this then in my book either you should not burn wood at all or you must be willing to put up with poor fires and dirty chimneys. You also must be willing to spend more on buying wood because if it is not ready to burn and you insist on burning it, you will burn more wood for the required heat. Summary: Keep it Simple, Sir. Cut your wood ahead of time and let Nature work in your favor. Time, wind and sunshine are firewood's friends.



Dennis, those of us fiddling around with moisture meters and the like are mostly relatively new to this wood-burning stuff.  If you're starting out and have no experience to go on, more actual data is helpful in figuring things out.  I've certainly found that after handling a lot of wood of a number of different species day after day, I start to lose my ability to figure out what's ready and what isn't, or at least I start to doubt myself.

Also, a great deal of this discussion is in aid of being able to make reasonable predictions.  If I had the resources to buy up three years' worth of firewood all at once in advance and get it stacked, and then buy kiln-dried wood to feed the stove for two or three years until the other stuff was ready to burn (or pay the oil man while the stove sits idle) I'd do that.  But I don't, so I have to gradually creep up on increasing my advance store of firewood and figure out how to at least get by in the meantime.

Please remember that not all of us have the ability to cut our own wood years in advance, and in any case, everybody has to start from the beginning at some point.

It's all very simple, as you say, but only if you've got an ample supply of stuff that's been sitting out for three or four years.  Not so simple if you don't.


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## Lumber-Jack (Mar 3, 2010)

Excellent reply Gyrfalcon, I would further add that much of Dennis's "book" likely has limited application to East coasters who have large lots and don't move very often. 
I don't stock up a 3 years supply of wood, and don't need to, and that goes for the vast majority of people who live out here. For the most part I cut my wood the year before preceding the season I intend to burn it, and my wood is likely just as "seasoned" as Dennis's wood, possibly even drier. The reason is we live in a different climate than Dennis, with different wood species and 90% of the trees cut for firewood around here are dead standing. In fact if you cut trees on the crown land (where most people get their firewood) you are only allowed to cut dead trees, you'll be fined if you cut live trees. Fortunately we have plenty of dead standing trees out here, and (here is where Dennis's book would be useless again) many of the trees are dry enough to burn immediately, although not all of them. This is why stockpiling wood is an unnecessary exercise. Why stuff your refrigerator with a 6 month supply of milk when you can just go to the store and get another jug in a few days when the one you have runs out? 
As I mentioned previously not all the standing dead trees out here are below 20% MC, so this is where a moisture meter can come in handy if you want to be real sure there is no chance of sticking a split in your stove that is over that 20% mark.

Also Dennis, I wouldn't be too amazed with threads in a forum like this where people go to great lengths to explore and share different facets of their hobby in detail, if this isn't the place to do it then where?
I have one older wood burning friend (probably been burning for 50 years as well) whom I have shared a few topics I have found in hearth.com and although he has a passing interest in what I was sharing with him, he finds it "amazing" that people would bother to join and actively (sometimes daily) participate in a forum on such a mundane subject as heating with wood.


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## Battenkiller (Mar 3, 2010)

Carbon_Liberator said:
			
		

> I have one older wood burning friend (probably been burning for 50 years as well) whom I have shared a few topics I have found in hearth.com and although he has a passing interest in what I was sharing with him, he finds it "amazing" that people would bother to join and actively (sometimes daily) participate in a forum on such a mundane subject as heating with wood.



What? You mean we don't _have_ to be here?

I just assumed daily attendance was mandatory.


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## Jags (Mar 3, 2010)

Battenkiller said:
			
		

> What? You mean we don't _have_ to be here?
> 
> I just assumed daily attendance was mandatory.



Just be careful.  If you are here too much they will slap labels on you like "moderator"....and thats just not fair to anybody. :lol:


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## Adios Pantalones (Mar 3, 2010)

I think I'm the primitive one.  No moisture meter.  No stove thermometer.  I do have a splitter though- one of my favorite and most dangerous toys.


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## woodsmaster (Mar 4, 2010)

I think someone might have to much time on there hands.


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## Battenkiller (Mar 4, 2010)

Adios Pantalones said:
			
		

> I think I'm the primitive one.  No moisture meter.  No stove thermometer.  I do have a splitter though- one of my favorite and most dangerous toys.



Adios, I never owned any of this stuff, either, at least not until I joined this group.  25 years with no thermometer, now I have three.  Before joining up here, I just thumped on my chest and tossed another log of green oak on the fire.  And I was too busy putting my eyes out with my own dangerous toys to bother with any of this nonsense.  Now I'm running around the house with my IR gun, scanning each plate of the stove and trying to figure out where all the heat really ends up, baking my wood until it smells like bacon cooking, trying to figure out if my wood is really freeze-drying, and reading about secondary burns.  Who cares about secondary burns... I don't really think I get them in my stove anyway, and I couldn't see them if I did.

You have all been very bad influences on me.  Got to get this heating season over with so I can get back to building some boats.  Besides, the guys on the WoodenBoat forum make you guys look sedate.  They're all crazier than bedbugs over there.  Makes me look like the sane one.  ;-P


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## NH_Wood (Mar 4, 2010)

I almost started to give this experiment a try, but....then decided to head out and get another cord of wood cut and split instead....seemed like it might take me just as long......Ha!  Cheers!


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## Adios Pantalones (Mar 4, 2010)

Battenkiller said:
			
		

> Before joining up here, I just thumped on my chest and tossed another log of green oak on the fire.   Who cares about secondary burns... I don't really think I get them in my stove anyway, and I couldn't see them if I did.



All the thermometers and moisture meters etc would be fun for me, but honestly- it won't really change the way I do things.  I burn dry wood reasonably hot and efficiently the way I'm doing it- as evidenced by my liner and the heat I get.  I care about secondary burns- reburning smoke is efficient as heck- I like that.  That is a good design feature for the way I do it.

I had a compost thermometer before I broke it- was fun to see how hot I could get my compost pile.  165F was about my tops.  Composted woodchucks, deer remains after I butchered it, etc at those temps.  Good fun- but I still compost without the thermo.


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## FLINT (Mar 4, 2010)

Battenkiller said:
			
		

> The wet looking spots on this hickory slice are actually sugars that have boiled out of the end grain and dried there.  Has anyone ever tasted the sap that exudes from wet hickory splits?  Yummy!  Too bad no one taps these things for syrup.




Actually, they do - here check it out - tulip poplar as well, 

http://www.lehmans.com/store/Kitchen___Pantry___Poplar_and_Hickory_Syrup___phsyrup?Args=


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## Battenkiller (Mar 4, 2010)

Adios Pantalones said:
			
		

> Composted woodchucks



Most excellent!  A fitting way to dispose of those woodchucks I shoot after they've eaten all the leaves off my prized Brussels sprouts.


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## gyrfalcon (Mar 4, 2010)

FLINT said:
			
		

> Battenkiller said:
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Nope.  Those are sugar syrups flavored with some kind of extract from the bark.  Maybe they're delicious, don't know, but they're not made from sap.


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## Battenkiller (Mar 5, 2010)

gyrfalcon said:
			
		

> Nope.  Those are sugar syrups flavored with some kind of extract from the bark.  Maybe they're delicious, don't know, but they're not made from sap.



Right.  There is some old guy out in Indiana that has made a commercial hickory extract syrup operation.  He gets loggers and farmers and such to gather shagbark that has shed from the trees, boils it with sugar, and then cooks it down just like maple syrup.  It's all the rage now among chefs from what I've read.

I'll just keep licking the ends of the splits.  It's very tasty stuff.  My wife thinks it's gross, but maybe she's referring to the green warts on my tongue.


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## DanCorcoran (Mar 5, 2010)

Don't say you weren't warned...


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## Bill (Mar 5, 2010)

Where do I find a micro-wave big enough to do a cord of wood at a time?


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## NH_Wood (Mar 5, 2010)

Smokey said:
			
		

> Where do I find a micro-wave big enough to do a cord of wood at a time?


LOL!


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## Battenkiller (Mar 5, 2010)

You don't need to do a whole cord at once.  Just bring in a day's supply, cut it all up into thin slices and MW them a couple at a time.  Shouldn't take you more than five or six hours tops to get a day's worth ready.  Besides, it's so powerful you only need about a couple splits worth to keep the stove cranking for at least 8 hours. ;-P


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## 'bert (Mar 6, 2010)

What you really need is a convection microwave so both parts of the experiment can be completed at once ;-) 

Cool experiment, but I agree with others that it should be redone to see how accurate the MM are.  Then one could factor in the proper amount of variance to make your MM readings accurate.  I can only imagine the lively turn the conversation would take if I told Mrs. 'bert that I want to put some firewood in her microwave.


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## Slow1 (Mar 7, 2010)

Sounds like something to do at the office after hours to me...  "don't try this at home folks!"  heh.

I really would rather like to have seen comparisons of the readings from cheap HF moisture meters (more than one model would have been best).  However, I do like the overall experiment.


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## Battenkiller (Mar 8, 2010)

Slow1 said:
			
		

> Sounds like something to do at the office after hours to me...  "don't try this at home folks!"  heh.
> 
> I really would rather like to have seen comparisons of the readings from cheap HF moisture meters (more than one model would have been best).  However, I do like the overall experiment.



A few folks here seem to agree with you on this, Slow.   I'd be more than glad to check any moisture meters anyone wants to send me.  I have a lot of wood that is in the range of reading for most inexpensive meters (6-30% MC).  If folks are interested, they should send them all at the same time and I'll run a small batch of the tested pieces through the MW and report the results here.  If the things work, I might as well get one for myself.  Keep in mind, though, these cheaper units are likely to vary somewhat between them compared to a pro unit like a Delmhorst.

Bear in mind, I did not have checking the burnability of individual firewood chunks in mind when I developed this test.  It's purpose was to find an quick and easy method to determined the MC in _wet_ wood so folks could keep track of the drying rates of their firewood during seasoning.  The idea is to randomly pull and test a couple pieces from the stacks at regular intervals to see under what conditions and when in the year firewood dries the fastest. A moisture meter is useless for this purpose since they only read up to 30% MC, and virtually every wood in existence has a higher moisture content than that when green.


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## DanCorcoran (Mar 8, 2010)

My $12.99 Harbor Freight model specifies a measurement range of 6%-42% for wood/paper/cardboard and 0.2%-2.0% for mortar/concrete/plaster.  You select which mode you need to use.  Whether or not it meets these specs, I don't know.  Accuracy for wood below 30% moisture is stated as +/- 2% and above 30% as +/- 4%.


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## Battenkiller (Mar 9, 2010)

DanCorcoran said:
			
		

> My $12.99 Harbor Freight model specifies a measurement range of 6%-42% for wood/paper/cardboard and 0.2%-2.0% for mortar/concrete/plaster.  You select which mode you need to use.  Whether or not it meets these specs, I don't know.  Accuracy for wood below 30% moisture is stated as +/- 2% and above 30% as +/- 4%.



Wow!  You'd have to spend $300 for a J-2000 from Delmhorst to get near that same range (6-40%).  I wonder if there are any other differences between the two units? :roll:  ;-)


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## DanCorcoran (Mar 9, 2010)

You could purchase 10 from Harbor Freight, average the readings, and still save $170 (if you were interested in greater accuracy).


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## Battenkiller (Mar 9, 2010)

Dan, I think you're on to something there.  And I could use the extra $170 to buy a new microwave for Lady BK.  The old one smells like burning oak for some reason.


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## djlarson77 (Jun 12, 2010)

Carbon_Liberator said:
			
		

> 90% of the trees cut for firewood around here are dead standing. ..... many of the trees are dry enough to burn immediately, although not all of them. .... not all the standing dead trees out here are below 20% MC, so this is where a moisture meter can come in handy if you want to be real sure there is no chance of sticking a split in your stove that is over that 20% mark.



This is somewhat similar to my situation.  When I bought my place in Oct '08 I began cutting dead standing and laying trees and some live trees that were in my way, mostly for firepit wood.  There was oak, elm, black cherry, box elder, cottonwood, and maybe a few other species.  I was cutting them about 16" and trying to keep them stacked according to species and approx. moisture content knowing I may get a wood stove someday.  Well I'm at that day thanks to the available tax credit.  So I see the benefit of having a moisture meter to help me sort through my existing 3 cords and any other mix of wood piles I'll generate going forward.  I'll obviously still use the various other techniques to know what's dry and what's not, but pairing it with a moisture meter on occasion seems like it might be a good idea.  

With that said - for those of you who believe in moisture meters and/or have one - any recommendations on a decent meter less than 100 bucks?  Less than $50 would be even better.  Thanks!


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## oldspark (Jun 12, 2010)

MinnesotaGuy said:
			
		

> Carbon_Liberator said:
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As stated before and in other posts I think the Harbor Freight cheapie is more than good enough for us wood burners, unless you break it as on person did (prong broke) it will do the job, no need for super accurate readings as this is not rocket science. The readings I get from mine are in line with the wood I have cut this spring, last fall, last spring, two years ago plus taking in account the different types of wood (ash, mulberry, oak, locust, silver maple) so save your self some money and but the cheapie.


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## gyrfalcon (Jun 12, 2010)

What Oldspark said.

You can also pick them up quite cheaply (20 bucks or so?) on eBay.  I got mine from there and it arrived within just a couple of days despite the fact that it came from Hong Kong!

One word of warning, though, about those prongs Oldspark mentions.  You want to get them as deep into the wood as you can, but the cheap meters aren't strongly built enough to do that easily without risking breaking off the prongs.  I push mine into the wood far enough to make a couple small marks, then use an awl or similar to make the holes deeper, then put the meter prongs back in to take the reading.  (And don't forget you need to split whatever piece you're gonig to test first so you're getting a reading from the interior, not the much drier exterior.)

I don't know that you're really going to need one much, though.  If you started in '08, you'll have plenty of dry stuff to play with and you'll quickly be able to tell the difference between dry and unseasoned, or semi-seasoned, wood just by the heft of it.


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## djlarson77 (Jun 12, 2010)

Sorry, I didn't see the Harbor Freight meter posted.  I just bought one for $19.80 shipped.

I know I don't really need one, but I want one.  Most of my wood was cut in '09 and '10.  Thanks for the awl suggestion, I'll try doing it that way.


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## yanksforever (Jun 12, 2010)

What was that an old triple beam you had left over from the 70's?  ;-)


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## Battenkiller (Jun 13, 2010)

yanksforever said:
			
		

> What was that an old triple beam you had left over from the 70's?  ;-)



 :red: 

Guilty as charged!


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## oldspark (Jun 13, 2010)

Battenkiller said:
			
		

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 Good old days?


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## Battenkiller (Jun 13, 2010)

oldspark said:
			
		

> Battenkiller said:
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These are the good old days (cough, cough). :coolsmile:


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