Drying wood

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heaterman

Minister of Fire
Oct 16, 2007
3,374
Falmouth, Michigan
I wish I would have had my camera along to take a picture of this..........

Was at the home of a customer and noticed a stove pipe sticking out of the middle of a covered wood pile and asked what was up with that. What the guy told me made sense so I thought I'd pas it along here.

He cuts his wood in spring (delivered in 8' sticks by a local logging company) and burns it the following fall. As in cut/split in April or May and starts burning now.

He stacks the wood and then covers it with a piece of black plastic tarp. Along the bottom he cuts a few slits in the plastic to allow air to move through. On the top of the wood pile he arranges some pieces a little higher than the rest of the wood pile to hold the tarp off most of the wood and create an air space. In the middle of the pile he placed a milk crate and used it to hold up a piece of what looked like 10" diameter stove pipe about 4' long, cut through the tarp.

In effect, he made a low temperature kiln which uses heat from the sun and natural air flow to dry his wood. Temps under the tarp during summer will hit 130-140* and he said on cooler mornings he has actually seen vapor coming out of the "chimney". Evidently the idea works because his moisture content runs 25% and less after only 4 months of seasoning and this is mixed hardwood such as oak, maple, cherry, beech etc.
 
Excellent idea. Thanks for passing it along Heaterman. I already have black plastic on the top and two of the four sides of my freshly cut wood pile. I'll give it a shot this spring. I'm guessing it would be better to go with the usual, air blowing through, in the cooler months.

Mike
 
Call me a contrarian if you wish (or anything else that comes to mind) but I feel that using black plastic causes the heat to convert when it strikes the surface of the plastic thus only producing radiant heat off the bottom surface of the plastic. I would think that using clear plastic would allow the sun to shine through and convert inside the covering. Several years ago I experimented with black and clear plastic in my vegetable garden while trying to get my soil to heat up sooner in the spring and found the areas covered with clear plastic warmed quicker and hotter than the areas covered with black plastic. For plants that like heat on the plant itself such as eggplant, I used black plastic and dropped an old tire around the plant.
 
Call me a contrarian if you wish (or anything else that comes to mind) but I feel that using black plastic causes the heat to convert when it strikes the surface of the plastic thus only producing radiant heat off the bottom surface of the plastic. I would think that using clear plastic would allow the sun to shine through and convert inside the covering. Several years ago I experimented with black and clear plastic in my vegetable garden while trying to get my soil to heat up sooner in the spring and found the areas covered with clear plastic warmed quicker and hotter than the areas covered with black plastic. For plants that like heat on the plant itself such as eggplant, I used black plastic and dropped an old tire around the plant.

I believe you are correct for maximum heat. Having a pool the clear solar covers seem to work very well. To look at it another way, on a sunny 90 degree day would you rather sit under a clear umbrella or a black one?

In reality the key would be having a way for condensation to exit the cover.

gg
 
I believe you are correct for maximum heat. Having a pool the clear solar covers seem to work very well. To look at it another way, on a sunny 90 degree day would you rather sit under a clear umbrella or a black one?

In reality the key would be having a way for condensation to exit the cover.

gg

Good points!

last fall(late) I started a round pile(8"diameter) on black top, got it to 7' high and then just covered the top with a tarp.
Left it like that through this summer and too kit apart 4 weeks ago. Cherry, ash, some black birch and a little oak(spilt small)all dropped, bucked an split in summer 2011. Average MC was in the mid teens!!.
The black top baked them..

Maybe next year I will put some pallets down and cover them with black heavy mil plastic and then stack on top, then cover the top with clear plastic and stick a chimney in the center..best of both worlds.

Thanks Steve..

Scott
 
When my dad was in the Peace Corps, they made vented the outhouses with a big piece of black pvc that ran from the pit up the side of the outhouse. He said you could tie a piece of cassette tape on the top and watch it get vertical and stay that way from the airflow. So yeah, I think the same principle applied to a pile of wood makes a lot of sense.
 
Interesting thought on the color of plastic....I have no idea if the guy experimented with it at all or just used what he had around. I would tend to agree that clear would allow for maximum heat "burn through". I think the other side of the coin though could possibly be that the black would become warmer and maybe prevent condensation from forming on the interior surface. The object is to get the vapor up and out rather than just getting the wood warm. It would seem to me that as noted, clear would allow more heat to the wood, it may also allow more condensation to form on the interior of the plastic rather than staying warm enough keep them evaporation in vapor form and let it get out of the enclosure. Just thinking out loud here....... I can see advantages with both methods.

I know that Dale from Econoburn has experimented with the European style of stacking wood and had found significant difference in dry time. Look up "holzhausen" for more info but the wood is stacked in a circular patern with the center of the pile vertical instead of horizontal to create an internal chimney effect.
 
Maybe next year I will put some pallets down and cover them with black heavy mil plastic and then stack on top,
Go to the dollar store and get a cheap space blanket. It will reflect the heat well.
 
This is the 'Next Big Thing' IMO. I might try it on my existing stacks. What have I got to lose?
 
I

I know that Dale from Econoburn has experimented with the European style of stacking wood and had found significant difference in dry time. Look up "holzhausen" for more info but the wood is stacked in a circular patern with the center of the pile vertical instead of horizontal to create an internal chimney effect.

That is exactly what I did, a hozhausen(woodhouse), all the logs in the middle were vertically stacked, while the perimeter was laid flat. Worked great on the black top.

Scott
 
Resurrecting this thread to see if anyone tried it last summer or is trying it this year?

If you did, how did it work? If you are trying it this year, check the MC of your wood going into the "oven" and then again when you start using it..
 
And stack some of the same splits outside up on pallets with a rain shedding cover on top only. Then compare the "oven"-baked with the stuff from open stacks. Then you would have a comparison between the two methods and not just a test to see if the tarp/stovepipe idea will dry wood at all.
This idea does the motherearthnews circuit every decade or so. My uncle read and tried it 30 years ago.
The wood does come out drier than it went in.
 
It sounds like a good thing, glad it works for him - My question, what happens when the wind really blows? Where does the plastic end up? I use metal roofing, etc, with whatever it takes to hold the panels down. Sometimes even those get peeled off when it really blows.
 
Interesting read. My FIL cover his tightly in March with a white tarp in a mostly shaded area and seasons it for 18 mos. I read here to keep it uncovered until Labor Day at least and usually can get it down in half the time although mine is usually drier to start(dead longer). It helps when I stack it next to my 14' high metal barn for the July-Oct stretch. It has to be 30-40 degrees hotter next to it and you can feel the heat radiate off the steel like an oven. Starting in Sept I throw a tarp over it when rain in forecast and move it to its completely covered (and shaded) winter location on back side of barn in late Oct.
 
You've, no doubt heard of the farmer who stacked all the hay he could outside and put the rest in the barn!!! Well I had a similar situation with my wood. My woodsheds became stuffed with the bonanza of free wood I was given last year so I needed to stack some outside. There's a local manufacturer that receives it's raw materials on pallets that are slightly longer than 8 feet and about 4.5 feet wide. I picked up several of them. One for the base and one for the roof. I stapled a poly tarp to the roof pallet and put a slight pitch for rain and snow run off. Working well for over a year now.

Wood pile 1 resized.jpg

Wood pile 1 resized.jpg
 

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You've, no doubt heard of the farmer who stacked all the hay he could outside and put the rest in the barn!!! Well I had a similar situation with my wood. My woodsheds became stuffed with the bonanza of free wood I was given last year so I needed to stack some outside. There's a local manufacturer that receives it's raw materials on pallets that are slightly longer than 8 feet and about 4.5 feet wide. I picked up several of them. One for the base and one for the roof. I stapled a poly tarp to the roof pallet and put a slight pitch for rain and snow run off. Working well for over a year now.

View attachment 134907

View attachment 134907


you may need a helo....to lift these
 
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My long time, seasoned wood supplier had a stroke so suddenly this post is relevant. Electromagnetic radiation (sunlight) hits a surface and the photon's energy is absorbed by the surface generating heat or transformation of electromagnetic energy to internal energy obvious on black cars. So the last thing you want to do is reflect the radiation or interrupt it before it gets to what you want to heat... so clear plastic. But not so apparent is if top venting to create natural draft, is better than Huff's post above, trapping moisture and let it run down the inside of the clear plastic. I Googled wood drying kilns and they all have transparent tops to let the sun energy in, air circulation, and top vent. So... I'll post some pics of my clear plastic wood drying kiln and moisture results this Fall.

I need to accelerate the seasoning process with my wood guy retiring. Bummer, I'm starting to lust for a pellet boiler.
 
And when I see these pics from Fred, I lust after a tractor with a front lift. ;) Good plan Fred.
 
And when I see these pics from Fred, I lust after a tractor with a front lift. ;) Good plan Fred.
I don't have anything that will lift those pallets nor do I now have anything that will lift a standard pallet. The big tractor went down the road and I now have a wimpy little Kubota with a 1200 pound lifting capacity and no forks. Good for digging in the flower beds. Downsizing!!! Those pieces of wood will be handled twice. They will be moved to one of the woodsheds when space opens up. They aren't in a good spot for access in the winter and I don't stack any wood indoors. A little more work but I can't walk away from free wood and besides, over the years I have become an expert wheelbarrow driver so "nothing to it".
 
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