Note: weldrdaves post above yours, he is basically saying I'm full of it. I got that same treatment in another thread on this forum.
Augie, This is simple.. I'm not saying your full of it …… But you need evaporation for drying wood, air movement to remove moisture! If you make heat, all you have is hot wet wood. Yes, heat brings moisture to the surface but it also will retreat when the temp cools down. When you incapsulate your wood the moisture has no where to go now all you have is hot wood, It's a greenhouse effect. cool for growing mushrooms and fungi. Kiln drying requires 220* and above "with" blowers and plenty of air. I'm not arguing with you, and it's a cool idea but without getting into great discussion, good old fashion air drying is still #1
I think what he is saying is that the water is driven out of the wood when the temperature is driven up and has no choice but to exit the wood. Now I believe what you are saying is true also, in that the water has no where to go.... but there is an in-between ground: when the water leaves the wood, it does so as water vapor instead of liquid water. The surrounding air absorbs that water and the relative humidity rises a great deal. But once water is driven out of the wood, there is nothing else trying to drive it back is so that water vapor condenses when the temp. drops during the night. That condensate just collects on everything- the wood, the plastic, etc. but as it cannot re-enter the wood, the majority of it runs down the plastic sheeting and collects in the bottom. As the heating / cooling cycle is repeated, more and more water is driven out of the wood. I am not saying none of the water will re-enter the wood but not as much as left in the first place. Same thing happens when wood is outside seasoning and it rains; yes the wood will absorb some water but not anywhere near as much or as fast as it left the wood in the first place. Or at least that is what I believe has been stated, and it does seem logical I think. Just my opinion of course. Brian
Yes, and it sounds like a great thing. Heres a thought, how does moisture get in a green house in the first place? The difference in temperatures between say 80* and 150* the molecules in the H2o do not move as fast as you think. to really get them excited, you need to pass the boiling point, 211.9* or above. If it's not above that, very minor movement of moisture will occur. The heat in the plastic will also cause the surrounding air in the plastic to condense the moisture, And the cycle will repeat itself. It is a good theory, but it's a "why" thing…. As I asked before
Dave, you are right, wood in Augies kiln will take moisture back on during the night and the exact same thing is happening to yours, mine and everybody else's stacks every day. But don't miss the fact that in Augies system a portion will condense and drain out. Once it drains its gone from his system. It can't get reabsorbed. Another thing you should look at is the drop in RH the will happen when the sun heats it up. I believe augie said he can see 150 degrees within the kiln. Assume a summertime low temp of 70 at night. At night the kiln will be at or near 100% RH, it's a terrarium at that point, no argument there. But come the next day that 70 degree air rises to 150. The RH is now going to fall to 9.68% if no new moisture is introduced. (You can figure that out with a dew point calculator) That heated air now has new carrying capacity. Water leaves the wood raising the RH. Sun goes down and it condenses, another portion drains and so on and so forth. That bump in heat is quite significant.
That is basically how I am viewing this. I think a key thing to remember is that wood will not absorb moisture as readily as it expels it; even the ends of the wood being wet by the condensate inside the plastic, the splits will not readily absorb much water. The way all that water gets into wood in the first place is when the tree draws it up the body in the first place and once the tree is dead, that mechanism is also gone. I would think that this whole solar drying system would work better if the plastic did not actually contact the wood but that would entail considerably more work and more materials than just covering the stacked wood with plastic sheeting. And of course if it works as well as is reported (and I have no reason to doubt it) there is really not much need to further improve or accelerate the process unless someone was desperate for wood to burn ASAP. Brian
Agreed but I did not mean a black covering instead of clear, just some way to make the overall color of the woodpile darker. Sorta', kinda' like spray painting it.... although of course I am not suggesting that as then we would have to burn the paint. But something <like> that that did not contaminate the wood. Maybe a big splash of lamp black (which is pure carbon and should be perfectly fine to run through a woodstove) slopped over the wood before covering it? Brian
Paul, I want to be clear. I understand the moisture will "not" re absorb into the wood but the moister will hang out in the plastic and contain a lot of whats in there. When you have air flowing in will simply evaporate quicker. And what I was saying is; Is it necessary to go through all this if you prepared? After nearly 40 years of C,S,S wood and reading everything about it, trial and error, etc.. All I'm saying is, is the time, effort, energy, $$$ and all that worth it. And why hasn't it been produced by some manufacturer as a kit? Frankly, "my personal belief " I can't see it working any faster. I'm "not beating up on Augie" I would just like to see some concrete experiments.
I've not done this myself, and don't plan to since I just don't need to, but Augie's results seem to make it pretty clear that using this kiln does make wood season faster
So you are saying the data I produced in this thread is not concrete? Did I fabricate it? In fact by saying it won't work any faster you are saying I fabricated the data, you are calling me out with a fairly bold claim.
Ok I'm only saying this to hopefully clear up your concern on moving air aiding evaporation Dave. You are RIGHT that wind significantly contributes to evap. Potentially more so than heat at ambient temperatures. If you rigged a fan in Augies kiln the wood would season even faster. Augies says wind doesn't matter cause his wood dries darn quick without the wind. In an Augie Kiln he is right, wind isn't needed (proof in the pudding) The thing is Dave and Augie, the "wind DOES aid evaporation significantly vs heat is all that matters" argument isn't comparing apples to apples because Dave is using logic from a "ambient temperature" set of conditions and Augie is speaking from an "extreme environment" set of conditions. Also to hopefully help with the back and forth, Can an Augie Kiln be improved upon with rigorous testing and modification using the scientific method? Sure can. Does Augie care? Nope, his wood seasons in less than a year, and he has (probably) the easiest way to do it. Well, hopefully that helped, I debated a while about if it was worth it to wade into this one...
The ONLY way to know fer sure is to do it fer yourself..if you want to participate great..if not thats fine too..everyone has their reasons...Augie was just putting it out there for us....give the guy a break...the whole should i top cover or not probally started in a thread similar to this...
If the only way to 'know fer sure ' is to do it yourself, we, as a species, would never advance. I don't need to test different tires to know which are the best, I trust someone else to do that for me. How much time, and $$$$, are you wasting by having to prove every single thing in your life.
