Slap together solar kiln.

Joe Hillmann · February 08, 2024, 04:12:40 PM

I am in need of a way to speed up drying of a couple stacks of pine lumber without going through the effort and cost of building an actual solar kiln

Looking on line I have seen people warping their piles in plastic film and leaving a vents on the bottom and top, and leaving them in the sun. Has anyone here tried this method? Did it work? My concern is it may actually slow down drying because it stops wind from blowing through the piles.

Another option I have is to build a temporary kiln on to the south wall of an existing building. The plan would be to build it out of a clear poly film, Styrofoam and a couple pieces of tin painted black.

The third option that would probably be the best but also the most expensive is to modify a winter greenhouse I have that is insulated by removing the tin roof and replacing it with a sheets clear poly roofing.

Does anyone here have any other suggestions for a cheap and quick way to speed up drying of my lumber?

DDW_OR · February 08, 2024, 04:18:13 PM

my 2 cents, about all it may be worth

How about a hoop greenhouse
plywood ends
or gather the poly at the end and secure to the ground with a rope

20 foot pipes
18 to 24 inch rebar pound into the ground
then rope at the top to secure the pipes at a even spacing

Joe Hillmann · February 08, 2024, 04:24:10 PM

Quote from: DDW_OR on February 08, 2024, 04:18:13 PMmy 2 cents, about all it may be worth

How about a hoop greenhouse
plywood ends
or gather the poly at the end and secure to the ground with a rope

20 foot pipes
18 to 24 inch rebar pound into the ground
then rope at the top to secure the pipes at a even spacing

That isn't a bad option. I would have to figure out a way for venting and fans that would force warm air through the pile.

doc henderson · February 08, 2024, 05:01:30 PM

I did a thread or added comments to a thread. I did about 8 bundles/logs worth of wood on the drive wrapped in plastic with box fans and a remote temp and humidity monitor. got the wood down to 7 %. got the idea in part from a timergreen farms publication, that can try to find.

rusticretreater · February 08, 2024, 05:30:19 PM

I know a fella who made a small tunnel(3 feet tall) out of wood framing and film sheeting. Setting in the sun. It was pretty warm inside it.

Old Greenhorn · February 08, 2024, 05:59:27 PM

Whatever you try, don't do it on open ground. You need a sealed floor are. Otherwise you will have more moisture coming up out of the ground than you are pulling out of the wood.
How much wood are you doing? Do you have an attic you can use?

doc henderson · February 08, 2024, 06:52:02 PM

https://www.youtube.com/watch?v=SC80TRU6Dk0

here are the bundles of wood. box fans in the center blowing through the stacks and covered with plastic.

beenthere · February 08, 2024, 07:30:07 PM

Quotea couple stacks of pine lumber

What do they look like? Hard to know what you mean by "a couple of stacks". pic maybe for us to see? How many board feet? Thickness of boards?

Joe Hillmann · February 08, 2024, 07:34:45 PM

Quote from: Old Greenhorn on February 08, 2024, 05:59:27 PMWhatever you try, don't do it on open ground. You need a sealed floor are. Otherwise you will have more moisture coming up out of the ground than you are pulling out of the wood.
How much wood are you doing? Do you have an attic you can use?

About 3000 bdft. My thought was to lay down plastic, then 4 inches of styrofoam insulation, then a pallet then the wood on top

At the moment it is probably 3 stacks of 7/8 thick boards 8 foot long the stacks 44 inches wide and maybe 6 feet tall(with 7/8 spacers between each layer.

doc henderson · February 08, 2024, 10:55:46 PM

air movement, and a temp of 20^oabove ambient and you will dry faster than air drying.

maple flats · March 13, 2024, 09:14:38 PM

I'm looking into the same thing. I however have planned it to the point that I'll get enough greenhouse poly to be the shell and the frame will be wood, I've sawn on my little manual mill, a woodland mills HM130 Max with 1 extension. I've got my brother's SIL on board to design and build another 5' extension. The sawmill is on it's own trailer and the extension will be added as needed and then removed, it will not remain on in transit. While I've been known to ridicule engineers, this one is very good (and the price is right). If and when either of these actually come to fruition I'll post pictures.

DDW_OR · March 15, 2024, 12:06:12 PM

i got 9 fir trees to drop and mill.
will use this information to dry the wood for my 12x32 greenhouse build
https://forestryforum.com/board/index.php?topic=124171.msg2025275#main_content_section

YellowHammer · March 15, 2024, 12:32:57 PM

Do you have a garage, shed or outbuilding relatively sealed up?

DDW_OR · March 15, 2024, 01:06:24 PM

Quote from: YellowHammer on March 15, 2024, 12:32:57 PMDo you have a garage, shed or outbuilding relatively sealed up?

yes, all FULL
moved 5 houses of stuff into the Montana house
now to sort, sell, donate, trash.
see you in 2 years

YellowHammer · March 15, 2024, 04:28:34 PM

Clear one out, put two 60 qt dehumidifiers in there from Lowe's, and call it a day.

Larry · March 15, 2024, 10:22:01 PM

What he said ^^^^ right above.

When I built my house the first thing I completely finished was the double car garage. Put several thousand foot of air dried lumber in the garage and turned the dehumidifier on....I only used one. By the time I finished the rest of the house the lumber in the garage was ready to use for cabinets, window/door casings, and the rest of the trim.

DDW_OR · March 15, 2024, 10:40:10 PM

never thought of using the 2 car garage for wood drying.
was planning to use it as a work shop,
but i will use it for the green lumber.

teakwood · March 16, 2024, 08:09:28 AM

put some fans in there too, to speed up the process

doc henderson · March 16, 2024, 08:39:31 AM

make sure to monitor interior relative humidity. may want to air dry a bit to reduce the daily moisture removal to that which the dehumidifier can remove. or spend some time with the doors up, if RH is over 80% so you do not damage drywall etc. in the garages.

YellowHammer · March 16, 2024, 09:04:41 AM

I agree, need to make sure the dehumidifiers are not overloaded, and can keep up. As a general rule, green wood will put out 5 gallons of liquid water per day, per thousand board foot, so that's a good way to size a load or area.

If they can't keep up, put a fan in a window, and that will exhaust any moist air outside immediately called "power venting", until the EMC gets down to where the dehumidifiers can keep up. Just don't want the moisture for the wood to overload the sheetrock, but if it does, then just open the garage door and "dump" moist air outside with the fans blowing the moisture out of the stack. Forced air flow is a great way to remove moisture, I do it routinely on stacks outside, especially in the warmer months.

Fans blowing though the stack are useful to prevent sticker stain as well as remove ,moisture, it's good to get at least 150 fpm, which is a light breeze.

I use all these techniques in my kilns - fans, power venting, dehumidification, and air dumping, there is no reason it wouldn't work in a garage.