Drying Lumber for use

I sold a mint tub to a sawyer and he painted it flat black and with a solar panel on it to keep the battery maintained for the exhaust fan (to pull the humidity out of the box) he could get a lot of wood in this. A mint tub in our area is approximately 6' wide, 5' high (tapers higher) and 12' long. He used to move the wood from side to side depending on moisture content. I won't go through as much board feet, but have two mint tubs that I will be putting by my new shop next summer, one will have the solar panel for battery for exhaust fan, the other will be without fan and dried wood will go to that one. Flat black absorbs a lot of solar heat and with the 12 volt fan, not much expense involved. Paint the ends to prevent checking/cracking as well as stick every 24" in a vertical line from top to bottom. Once I have decided on a specific project, I plane and bring the wood into a close as specs as possible. In winter, I keep the wood in the house specifically in the room I am building for so the wood becomes acclimated. In the summer I don't worry about this as we don't use air conditioning.

TexasTimbers, nope, no photos, you have hit the proverbial nail on the head on my lack of ability to be a participant on some sites. I just am not a photographer or even think about having a camera with me. In our part of Indiana a lot of mint is raised. To harvest mint you mow it much like hay except you don't "crimp" it. Then a chopper picks it up, grinds it up and blows it into a box type wagon. The newer version of mint tubs are a rectangular box, the front is higher with a rectangular hole for the mint to be blown in the box through. Once at the still this top rectangular hole is covered with a lid and pipe where steam is put in the tub. Around the perimeter of the tubs bottom is a collection pipe where the mint oil and water (cooled steam) run out of the tub. Once the oil is collected the mint tub is taken to a field and the back is one large door that hinges from the top and the tub hydraulically is raised and the mint waste (called plummies (sp?)) is dumped. Some times mint tubs can be acquired because the slightest pinholes allows the oil to escape without going into the collector pipe thus costing money. They make great sheds as they are made out of steel. I will work on getting a digital picture this week. It is -8 out at the moment and wind chill of -28 so am not running out right at the moment as cattle and horse chores are done for the morning!

Harddog,
Wood will reach what is called EMC, or Equilibrium Moisture Content no matter where it is placed. If it stays in an envrionment which has little RH changes then it will not move much but, it will move.
It can re-absorb a suprising amount of water once it is exposed to high RHs.
A real basic understanding of how wood holds water is, there is bound water (water within the cell) and free water (water between the cells). Air drying can remove most of the free water, but to get the bound water out it takes higher heat and a method to remove the water from the wood, by forcing the cells to give it up so to speak.
This is very basic, and I don't claim to be an expert but you get the idea. Once the wood is dried in a kiln, the battle is not won. You must decide where the piece will spend most of its life but remember, when you die your kids may decide that coffee table you designed for indoor use only would look better out on the screened in porch. :blink:
Of course there is nothing you can do about that my point is wood will absorb lots and lots of water if exposed to high RHs again.

NUTMEG CARVER said:

wood has been cut assemblied and finish dose the re-absorbing still take place?

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Yes, and so does drying back out again. I am sure there is someone who can explain it more clearly, but here I go at an attempt. Once equilibrium (in the average rh of the woods environment) is reached the changes in the % of moisture in the wood is not that big of a swing up or down. Just a few % either way. If you kiln dry the wood, then it is moving back and forth between 10%-14% for example that has little effect on the cell structure of the wood, thus little movement.
Ok, now if you build something from a piece of wood that has air dried to 20% in a years time then it is dragged inside in the middle of winter. It is going to lose more moisture and change shape in a matter of several days (shrink, bow, warp..) I know that is a simplistic answer with vague numbers, but that's all I got without going into a long boring post that 1/2 of what I say may not even be based on the science of drying wood. (cause I don't really understand all of it :laughing
As far as how long the wood take to reach equilibrium, that depends. (wood species, thickness, rh...) Even location, I have had wood that I kiln dried and let set for a year in stacks. The wood was perfectly flat when it left Illinois to go to California customer. He called me and said the wood (24" wide 4/4 slabs) had a very noticable cup across them, what should he do? I said "Nothing, let them set in your shop for 3-4 days and call me back". He called me back at the end of the week and said everything was fine, they flattened back out. They dried flat and returned flat one equilibrium was reached.
I guess the moral to the story is wood is organic and it will move with changes in moisture, wide boards more obviously. Proper drying and joinery techniques just helps minimize the bad effects of that movement.