Fresh felled and split black locust at MC 20-25% (!?)

[dave11]

Had a big locust felled on my property last week, and have been splitting the deepest parts of the trunk. Stopped to take some MC readings, with a meter that's always been reliable. Highest reading=25%, lowest=20%. That amazes me, for a tree that until six days ago was standing and reasonably healthy. Had it been felled in the spring/summer, the MC likely would have been higher.

I know folks here sing the praises of black locust, but this surprised me to see. And it splits easily into blocks that resemble 2x6's. Might be because it is frozen.

But for folks short on wood, getting hold of some locust somehow just might save the day.

If it were just a bit drier, I might just chuck one in the stove to see how it burns.

 

[Bigg_Redd]

Had a big locust felled on my property last week, and have been splitting the deepest parts of the trunk. Stopped to take some MC readings, with a meter that's always been reliable. Highest reading=25%, lowest=20%. That amazes me, for a tree that until six days ago was standing and reasonably healthy. Had it been felled in the spring/summer, the MC likely would have been higher.

I know folks here sing the praises of black locust, but this surprised me to see. And it splits easily into blocks that resemble 2x6's. Might be because it is frozen.

But for folks short on wood, getting hold of some locust somehow just might save the day.

If it were just a bit drier, I might just chuck one in the stove to see how it burns.

It shouldn't. For the gajillionth time: Locust (both varieties) is very low moisture woods.

 

[dave11]

Had a big locust felled on my property last week, and have been splitting the deepest parts of the trunk. Stopped to take some MC readings, with a meter that's always been reliable. Highest reading=25%, lowest=20%. That amazes me, for a tree that until six days ago was standing and reasonably healthy. Had it been felled in the spring/summer, the MC likely would have been higher.

I know folks here sing the praises of black locust, but this surprised me to see. And it splits easily into blocks that resemble 2x6's. Might be because it is frozen.

But for folks short on wood, getting hold of some locust somehow just might save the day.

If it were just a bit drier, I might just chuck one in the stove to see how it burns.

It shouldn't. For the gajillionth time: Locust (both varieties) is very low moisture woods.

It's one thing for you to say it. It's much more interesting to prove it, you know, with real numbers.

 

[SolarAndWood]

Locust is super easy to split in blocks frozen or not.

 

[Jeb1heat]

Okay, so how long after being down is the locust ready. I'm curious because I have a driveway full.

 

[dave11]

Okay, so how long after being down is the locust ready. I'm curious because I have a driveway full.

I was going to check it again in 3 months, and if it's reliably 20% or less, I was going to burn some then. It'll be March, still lots of burn time left in these parts.

 

[bsa0021]

I have some locust (not sure if it's black locust) but it's been drying split for 2 years and I threw a piece in the fire the other day and I still had a small amount of moisture on the ends.
I think your moisture meter is broken.

 

[dave11]

I have some locust (not sure if it's black locust) but it's been drying split for 2 years and I threw a piece in the fire the other day and I still had a small amount of moisture on the ends.
I think your moisture meter is broken.

I doubt it. It reads 30% on a pile of split oak that was cut and split 18 months ago. And reads greater than 35% on some freshly split Poplar.

 

[Dune]

Yep, thats why you can burn green locust. Like any wood though, you will get more heat from it if it is seasoned well.

 

[JerseyWreckDiver]

OK, I'll say this one more time.

Different woods at exactly the same moisture content, say, oven dry, will give different readings on a moisture meter solely because the wood species has different mechanical properties that skew the reading. The same way two different woods give very different BTU output. Most moisture meters, the good ones anyway, come with a chart of correction factors for the different species. You take the reading that you get from the meter and then multiply it by the correction factor to get the actual MC. You should be able to find one on the web somewhere.

Try here; (broken link removed to http://www.csiro.au/solutions/HandHeldMoistureMeters.html)

To some extent you are right, locust starts off with a very low MC and being felled this time of year it will be the lowest possible. But you do have to factor in the correction. (sorry, I don't have my chart nearby).

 

[Bigg_Redd]

Okay, so how long after being down is the locust ready. I'm curious because I have a driveway full.

Locust felled in the spring/summer can be ready for that winter.

 

[DBoon]

The density (and probably the grain also) of the wood has a huge effect on moisture readings of different types of wood.


An inexpensive moisture is a good tool for quick checks of wood moisture content. It's probably the best tool if the user is not inclined to want to do math corrections when testing wood. Math corrections are required to account for different types of wood IF you want to achieve the highest accuracy.

The more expensive moisture meters (we're talking around $100 or more) can do the "math correction" for you if you enter the type of wood you are testing.

The most inexpensive and still very accurate solution for moisture testing is an electrical multi-meter to measure the resistance of the wood, and then convert it to moisture based on a lookup table. This is detailed in this thread https://www.hearth.com/talk/threads/44360/.

If you looked at hickory, for example, the resistance of hickory at 20% moisture content is the same resistance as sugar maple at 24% moisture content. Thus, an inexpensive moisture meter would read these 4% differently. The difference is larger or smaller for other types of wood. There is no lookup table for locust in the referenced USFS document, so I don't know how much locust would be different by, but my guess is that since it is one of the most dense woods, it might be off by even more. Thus, the inexpensive moisture meter could be saying that your locust is 20% and it could be closer to 30%.

 

[dave11]

OK, I'll say this one more time.

Different woods at exactly the same moisture content, say, oven dry, will give different readings on a moisture meter solely because the wood species has different mechanical properties that skew the reading. The same way two different woods give very different BTU output. Most moisture meters, the good ones anyway, come with a chart of correction factors for the different species. You take the reading that you get from the meter and then multiply it by the correction factor to get the actual MC. You should be able to find one on the web somewhere.

Try here; (broken link removed to http://www.csiro.au/solutions/HandHeldMoistureMeters.html)

To some extent you are right, locust starts off with a very low MC and being felled this time of year it will be the lowest possible. But you do have to factor in the correction. (sorry, I don't have my chart nearby).

Well, I guess if you're buying lumber to build high-end furniture, or in large volume, it would be important to make the small correction for species. Also depends on the temperature and whether you're using a resistance or capacitance meter, etc.

But for firewood, it's not that important. The readings are always approximate anyway, and most species are within a few points of the reference douglas fir, especially in the firewood range of 18-25%. So whether the locust is really 20%, or a little above or below, is immaterial. As I said, I'd recheck in three months to make a comparison, which will tell me far more than a single MC reading today will tell me.

In other words, I doubt that any firewood reading 15% on the meter is not ready to burn, regardless of species.

 

[dave11]

The density (and probably the grain also) of the wood has a huge effect on moisture readings of different types of wood.


An inexpensive moisture is a good tool for quick checks of wood moisture content. It's probably the best tool if the user is not inclined to want to do math corrections when testing wood. Math corrections are required to account for different types of wood IF you want to achieve the highest accuracy.

The more expensive moisture meters (we're talking around $100 or more) can do the "math correction" for you if you enter the type of wood you are testing.

The most inexpensive and still very accurate solution for moisture testing is an electrical multi-meter to measure the resistance of the wood, and then convert it to moisture based on a lookup table. This is detailed in this thread https://www.hearth.com/talk/threads/44360/.

If you looked at hickory, for example, the resistance of hickory at 20% moisture content is the same resistance as sugar maple at 24% moisture content. Thus, an inexpensive moisture meter would read these 4% differently. The difference is larger or smaller for other types of wood. There is no lookup table for locust in the referenced USFS document, so I don't know how much locust would be different by, but my guess is that since it is one of the most dense woods, it might be off by even more. Thus, the inexpensive moisture meter could be saying that your locust is 20% and it could be closer to 30%.

Actually, i'm pretty sure that density is not the major factor contributing to the differences in moisture measurements among woods, at least as far as resistance meters go. Capacitance meters depend on density, resistance meters depend on the chemical composition of the wood. So there's no way to guess what the correction factor for black locust is. It might, in fact, be very close to douglas fir, as are most other woods, in which case the correction factor is too small to worry about for firewood.

 

[bsa0021]

I would think any living tree (especially with bark) that has been cut down will not be immediaetly ready for burning (at least I wouldn't use it in my stove). Just throw a piece in the fire and check for moisture on the ends. I use my MM to check my drying process throughout the year. As a general rule hard woods 1-2 years softwood 6 months- 1 year. On a rare occasion, I'll find a barkless standing tree that is ready to burn but never a living tree.

 

[Tony H]

I have some honey locust trimmings from my FIL tree this summer some branches up to 8". I split it right away and it's down at 20-25 MC right now
Just burned some the last couple days and it burned great. I would not expect the lower trunk of one of those trees to be dry enough to burn quite yet.

 

[golfandwoodnut]

I did a thread on Sassafras recently, it is in the same family as Locust. I also recently cut some Sassafras and Locust with low moisture readings of 20 to 23 percent. I found they will burn OK freshly cut and I noticed no mosture at all from the ends. I am sure they will burn better after seasoning 90 days. I was fortunate this weekend that I found a dead Locust (probably 15 years dead) and as you may know Locust rarely rots. The moisture content on this tree is only 15 percent and it already burns like coal. The best test is get the coals fired up and throw a piece on and see what happens, I would doubt you will see much or any mosture coming out.