Finally am doing one. This is 2 cords of red oak felled, bucked last fall. Split, stacked mid June 2022. Pallets on ground. Wrapped from stack bottom all way around and to top with shrink wrap. Then topped with 3 mil plastic sheeting 10' x 25' and stapled to splits. Cut a hand size vent in top at apex of each end. Stack is 4' x 4' x 24', I think it is six pallets. Has been a heat wave its first 2 weeks. The last 5 days, the outside air has been 100 deg to 102 deg heat. This stack is in my pasture, has much full sun daily. Pretty much all day, say, 7am to 7pm. Am wanting to know temp inside. Was going to use an Oregon weather station I have but it's limit is 130 degrees, so, I don't want to melt it! Wish it would work cuz you can view min max temp range. Now wondering about just using a meat thermometer to measure a wood split temp I could poke into inside a vent. Any ideas? Sent from my SM-G960U using Tapatalk
Ok I just went and used a meat thermometer and outside air at 9:45am was 80 deg and at the vent flap, wood measured 113 deg. Cool front came thru and will only be 90 deg today but it will be hot again in a few days. If temp is, say, 95 deg, I would think it would get up to 130 to 140 deg. Sent from my SM-G960U using Tapatalk
I like it. Simple and effective. Itd be interesting to stack the same wood uncovered right next to it for an experiment to see how well it works.
You are SO right, Brad, and I have a big pile of splits close by there, I will make a stack 4 ft high for a test. I used 3 mil for the top. I suppose 6 mil would be better but it's $40 for the roll (10x25) and, to me, that is too much, takes too much profit away for a sale. But if one were going to do this long-term, the 6 mil would certainly last longer. I have no idea if one can get more than one season out of 3 mil. The expense for this 2-cord stack is some staples, a roll of shrink wrap (did not require the entire roll, unsure how much was used, I still have the rest) and the 10x25 3 mil plastic sheeting. I scrounge pallets for free, I have yet to pay for any. The oak started at 40%. I hope to get this solar kiln stack to less than 20%. I am guessing that a regular stack (not a solar kiln) done nearby for just this one summer will only reduce to low 30s.
I'm interested in how this turns out because my first reaction when I saw that pic was this wood is wrapped way to much. Looks like it'll never dry. Hopefully I'm wrong.
My thoughts exactly. Is this thing somehow vented? Any way, air flow, to move the moisture from under the plastic?
Yep, but there are tons of water coming out of that wood. Just seems like all that moisture may need a little extra help getting out of 2 vents.
The solar kilns I have read about have the weep holes (slots) at the bottom of the plastic encapsulated wood pile. Not so sure having a hole ("VENT") on the top of the pile would be beneficial as it would have a tendency to exhaust the warm(hot) air. Good luck with the solar kiln and looking forward to updates on it.
I think the other ongoing Solar Kiln thread explains the desired design intent well enough- Solar kiln build
I should have included this in last night's post. Back when the first solar kiln thread was posted, I thought I'd give it a try. Only thing is, I didn't wrap the entire pallet. I just wrapped the sides from the bottom up and but didn't wrap the bottom. I'm sure it must have helped some but with negligible results, I never did it again. I didn't use a MM or a thermometer; I just judged by the amount of condensation on the inner plastic.
without wrapping the bottom I imagine the ground moisture evaporates up and is trapped. Eventually the ground drys at least somewhat due to being top covered. A solar kiln without a bottom is more like fully covering a woodpile. Just a little extra sun to help. JMO
Until recently, I had never seen references to building solar kilns putting plastic atop the pallets before stacking and then drilling/cutting 'weep holes' into the plastic for condensation to have a place to go. Recently, I came across an old thread here where a fellow claimed he had great success with just such a design. People told him it would not work without vents and he was adamant that it will and he had proved it more than once. Prior to reading the weep-hole method, I had only read about solar kilns from another source (for several years) and the builders on there built theirs like I have built mine, with small vents. Pallets on ground, stack three rows wide, four feet high. Wrap shrink wrap around the sides, staple 3mil or 6mil plastic sheeting on the top. Cut a vent at each end at the apex. I read that if there is still significant condensation on the inside of the plastic, make bigger/more vents. It was mentioned that bottom plastic might not hurt but isn't necessary. The main players there claimed without any doubt that this method works great, that great results can occur in one summer. Time will tell. Throughout the day, mine swells with air that I assume enters from the bottom, gets heated (obviously, as I reported a mid-morning 113 deg with ambient temp of 80 deg) and escapes out the two vents. My kiln pulses like it's alive. Which may be due to the light winds of summer or the kiln heating. I sure hope it works as I was told.
TurboDiesel linked it on page two of the thread I cited above. But to make it easier on you Stin, here ya go… Solar Kiln Firewood Drying
