My Seasoning Season Ended….2 month ago…Drying Experiment Cont'

[skyline]

Just thought I would send along an update of the graphs of the drying experiment. I finally got my first piece of fresh Oak to add to the experiment.

To recap: I started seasoning 7 splits from a Doug Fir felled, c/s/s the same day and started weighing back on April 18th. I compared 6 of them to a control split of the same group that I put in my unheated garage. For the first month I just had the 6 split on the top row of my stack. For the 2nd month I moved them next to each other to make it easier to weigh with A & B no cover, C & D clear cover, and E & F solid cover. See picture. There didn't seem to be any significant difference other than less rain wt gained for those covered which was more quickly lost. The cover blew off in July and I left them off. The number on the legends in the graphs refer to each splits starting weight in grams (Between 9-16 lbs). On June 21, I added 4 new fresh splits of maple to the experiment. I was more careful in making these 1/2 round splits of progressively larger sizes. I also added a 21" freshly cut down round(not split) of cedar on July 23. On Oct. 16, I got my first split of Oak. What a heavy son of gun, no wonder folks like it so much.

Previous posts:
https://www.hearth.com/talk/threads/75789/

https://www.hearth.com/talk/threads/76692/

From the graphs what should be clear is that the fresh "live" c/s/s wood will dry quickly at first, practically no matter the conditions. See Portland's weather last April-June if you have any doubts.
The maple added in June arrived about the time the good weather did so their moisture loss is steeper than the fir. While not as fast as split, rounds will definitely dry if conditions are right.

It has been 2 months and my splits have lost no more moisture and I wouldn't except any more loss unless I get them under cover with air movement. It's not that seasoning won't still occur, but at this point my splits have lost so much moisture that the gradient between their moisture content and outside EMC conditions is fairly flat, thus little driving force exists for the moisture to leave. Just like what happens almost every night during the entire seasoning process.

What is really clear is that most of the moisture can be lost in a very short period of time and most of the time wood is outside "seasoning" is wasted, as it the few hours where conditions are just right that really drive the moisture out. It wasn't uncommon for the splits to lose as much moisture in a sunny afternoon as in an entire week. When the wood is fresh and really wet, it has little trouble losing lots of moisture even in pretty wet conditions. I had loss rates in the first few weeks as high as 250g/day! Of course, as it get drier and closer to ambient EMC, it really slows down.

As you would expect, the bigger splits lose a % of their wt. more slowly than smaller ones but a longer skinny split of the same wt will dry faster than a shorter fatter one. What a long year of seasoning does is allow the fatter heavier splits catch up with the smaller splits that dried more quickly. Lots more I could say but I'll let the pictures do the talking.

 

[gmule]

cool graphs and great info
:coolsmile:

 

[maverick06]

Spectacular

So from this, in your conditions, 80 to 100 days = seasoned.

this is fascinating... Seems like something I would do... and we have the same fireplace! Great minds think alike ! haha

good work!

So what do you do for a living? scientist or engineer?

 

[scotvl]

so from what you're saying the honeylocust I css last week won't be ready by march then.

 

[SolarAndWood]

Thanks Skyline, I got busted this morning outside weighing a split of Oak

 

[Battenkiller]

All the dumb moisture meter threads in this place and this one only gets a smattering of hits. Go figure, eh? :shut:

I think these are awesome findings, Sky. Thank for taking the time to do this, I personally feel that info like this is invaluable to new burners.

I am a bit confused... OK.... stunned by the maple data. Am I seeing that the maple lost up to 65% of its starting weight over a 3-month time span? And then regained 20% of the original weight due to rain? Or am I still so groggy that I'm reading this all wrong?

 

[JrCRXHF]

Well done this is good information thank you for taking the time to run the samples and take the data.

 

[oldspark]

Guilty as charged, I saw a graph and moved on but now that I read your post I find the info interesting, the fact that it loses a lot of moisture quickly has been known but not too many people believed it, sounds like we are not gaining all that much by leaving it set out side for 2 to 3 years, I just dont have a wood shed big enough. Nice job on the fact finding.

 

[Cowboy Billy]

Thanks Skyline

Thats a lot of help. And also shows what I felt was happening with my fire pit wood. A one day rain storm did not seem to bother my wood much. But when I would have a week long rain my outside wood was almost impossible to start and didn't burn well when it did.

Billy

 

[Battenkiller]

Guilty as charged, I saw a graph and moved on but now that I read your post I find the info interesting, the fact that it loses a lot of moisture quickly has been known but not too many people believed it, sounds like we are not gaining all that much by leaving it set out side for 2 to 3 years, I just dont have a wood shed big enough. Nice job on the fact finding.

This is what I found in my indoor drying experiment as well. If fact, if you invert my drying curve (it was based on % of original weight remaining rather than % water lost) it is the same shape as Sky's control curve.

It's so funny to me that so many here take this stuff so literally. My study was never to try to get folks to dry their wood indoors, just to get accurate weight change data to establish a drying curve. The most significant implication to all this is that folks can just toss their moisture meters away and get a good scale. Weigh a random selection of splits and reweigh them at periodic intervals until they fail to drop in weight anymore. At the point there is little outside several years drying that will lower the moisture content at all. Also, since I knew the starting MC by running the oven-dry test, I was able to demonstrate that the point where the wood seems to just stop dropping in weight is well below 20% MCwb. Therefore, if you weigh your sample splits until the weight change essentially disappears, your wood is below 20% MCwb at that point. Of course, the punch line was completely missed. Forget about my dry sense of humor, it appears that even my science is too dry for for most folks.

We really need a "Eureka" emoticon here. :blank:

So, again... why do we need to putz around with cheap electronic devices from the Orient that nobody seems to trust anyway? Weigh several samples of your wood. When the drying curve flattens out, it is all well-cooked and ready for the shed. And this will work in any climate in the world.

 

[skyline]

Thanks to all, a little payback for all the good advice I've gotten around here.

Spectacular
So from this, in your conditions, 80 to 100 days = seasoned.
this is fascinating... Seems like something I would do... and we have the same fireplace! Great minds think alike ! haha
good work!
So what do you do for a living? scientist or engineer?

Used to be, still clinging on I guess!

Maverick, 80-100 days seasoned? Could be, but not exactly what I meant to convey. I just want folks to see how wood really dries.

I should be really clear as I, and perhaps a few others, have been guilty "in the past" of burning wood a bit too green. And it has been the collective wisdom of this forum that has helped correct the errors in my ways.

My goal and others should be: To have more "seasoned" and less "wet" wood burned in stoves across America, so I don't want to contradict the sound, practical advice of "single row, top(only) covered, etc. year-long seasoning time." What I do want to do is increase the understanding of how wood really dries and perhaps improve the methods we use to get seasoned wood, (think solar) especially for the folks that don't have the space or time for the method above.... or honesty from firewood dealers!

That said, it is clear from my results, I can go from 100%+ MC to 16-25% in 60-90 days (in outside & open air conditions) if starting between mid-April-July in NW Oregon (Doug F. and Maple). The smaller (14 lb) skinny splits no problem down to 16% where seasoned would likes end up around here. The trouble is with the bigger (16+lb), more rounded splits (see pic). If I assume the 2 splits in the picture (again, from the same tree) started at 100% MC, (This is higher MC than most folks are used to dealing with) after 70 days, my smaller split is at 17%MC but the larger one is at 44%. I'm sure they didn't really start out the same, the larger split was from lower in the tree, had more heart wood, knots, and I'm guessing started around 90%MC while the smaller one started around 115%MC. Even with those assumptions it means after 80 days they were at 16% and 28%.
So unless you can make all your splits the same like Zap, then don't plan on all your wood being dry. What should be really clear is that last 5-8% is what really takes the time.

so from what you're saying the honeylocust I css last week won't be ready by march then.

No guesses about honeylocust in your location. Just know that it is a small amount of time in the right conditions where all the moisture is lost. Just look at my control piece in the garage.

All the dumb moisture meter threads in this place and this one only gets a smattering of hits. Go figure, eh? :shut:

I think these are awesome findings, Sky. Thank for taking the time to do this, I personally feel that info like this is invaluable to new burners.

I am a bit confused... OK.... stunned by the maple data. Am I seeing that the maple lost up to 65% of its starting weight over a 3-month time span? And then regained 20% of the original weight due to rain? Or am I still so groggy that I'm reading this all wrong?

Thanks BK. You read that right. They still have their bark on with moss (see pic) so I suspect that helps soak up the rain. Just know that if I move that maple under a roof, they would re-lose that last 20% in less than a week (my guess) rather than the 40 days it took to lose it the first time. In fact, I think I'm ready to move the whole experiment under the barn since they are not going to lose anything being outside until next June.
I'll let you know how it goes.

Cheers!

 

[skyline]

BK,

Thanks again for the encouragement, I was in the middle of posting when your last post went up. I thought the spreadsheet picture below might be useful to folks who endeavor to weigh their wood.

It's how I calculated a MC (the oven dry style) by "assuming" a starting MC without having to actually oven dry my wood or wait until the experiment was over.
Once it got down in the range of my cheap moisture meter (yes, I admit I have one :red: )I could check the meter against my assumption.

You might test it on some of your data and see if it works for you.

 

[Danno77]

Awesome. I'm going to take some time to look at this a little more later, but I tink I might be interested in getting my hands on he raw data, or your spreadsheets if you'd be willing to share.

 

[Jags]

All the dumb moisture meter threads in this place and this one only gets a smattering of hits. Go figure, eh? :shut:

Hey, my moisture meter is smart - its the wood that is stupid.

 

[oldspark]

Backwoods aint gonna like this wood weighing thing. :cheese:

 

[ohlongarm]

Very, interesting but unfortunately I don't have the time for experiments and scientific data as complicated as this,but it was enjoyable and informative. I guess I'll stick to visually checking the ends for cracks and whacking two splits together it's all in the sound works for me.

 

[Battenkiller]

Backwoods aint gonna like this wood weighing thing. :cheese:

:lol:

Nobody's gonna like it, I'll bet. They'll be plenty of cognitive dissonance going on here within the membership for sure. ;-)

 

[skyline]

Backwoods aint gonna like this wood weighing thing. :cheese:

:lol:

Nobody's gonna like it, I'll bet. They'll be plenty of cognitive dissonance going on here within the membership for sure. ;-)

No dissonance intended. Backwoods can take pride in getting me on the program that works year in and year out for most everybody and if I could make stacks as pretty as his, I'd do it more often.
It's just that my poor planning and our NW weather leads me to look for short cuts and the way wood seems to dry leads me to believe there is a lot of room in that area.

I promise I'll send results of my experimental shed, good or bad :cheese:

 

[cottonwoodsteve]

Saying wood can dry (age) quickly is not well received by a lot of people. Having facts and data may upset the rituals and traditions. The chant is, age one year minimum, 3 years better. That makes people feel better. Short drying times sound cheap and un-educated. Just as saying "aging" or "seasoning" is more important than saying what it really is....drying.
Never call it drying. It's just not allowed.
Saying wood can burn fine in a few months and you have the villagers at your door with torches and pitchforks. Mentioning facts and test data just irritates them even more.
See my other post. Not as exact as your data. The some wood, in some climates doesn't need much more than 3 months in the summer.
https://www.hearth.com/talk/threads/81577/

The only reason the villagers haven't burned me at the stake is I pointed out their wood less than a year old so it couldn't possibly work.

 

[SolarAndWood]

What is the average windspeed at your house skyline? Do you show up on the map as at least fair?

(broken link removed to http://www.nrel.gov/gis/pdfs/windsmodel4pub1-1-9base200904enh.pdf)


Someone here is eventually going to develop a model that predicts with a high level of certainty how long it takes to dry any piece of firewood anywhere. I'm pretty sure that model is going to show that the Backwoods plan will ensure dry wood for 99% of species found in the U.S. at 99% of the locations in the U.S.

 

[barkeatr]

THIS IS outstanding work, real science!

i have read through the posts quickly.....but..what caused the increase of moisture around day 175 or so?

tim barkeater

 

[mecreature]

Very, interesting but unfortunately I don't have the time for experiments and scientific data as complicated as this,but it was enjoyable and informative. I guess I'll stick to visually checking the ends for cracks and whacking two splits together it's all in the sound works for me.

You can still make a nice graph.

I don't trust any study that does not use an oscilloscope.

 

[Jack22]

Wow this is great information. Thanks for sharing your findings. If I were to season my wood inside an outbuilding would I want good ventilation to the outside? Or would this defeat the purpose on those wet humid days by allowing humidity in the building. I also figure if there is no ventilation you will have a high level of humidity from the green wood.

 

[Jags]

would I want good ventilation to the outside?

Conventional wisdom says ventilation or breeze.

 

[Battenkiller]

I also figure if there is no ventilation you will have a high level of humidity from the green wood.

True, that why you need to provide ventilation, whether it is mechanical or natural (wind). The air surrounding the splits would otherwise quickly approach 100% RH, at which point drying essentially ceases. However, you don't need as much air movement as you might think. Just a few MPH of moving air has a remarkable effect on drying time. That's a lot easier to do outside than inside a shed, which is why most folks dry outside in single rows and move the wood into the shed once it is dry.