Late Season / Winter Solar Kilns

[jaoneill]

Thanks fo posting. Im glad to see this working out for you. I like your stacks i would hope that you will keep posting your results. The seasoning will slow as we get closer to winter, but you will see results.. please post what they are..

A lot of experimenting with stacking the pallets over the last few years. Started with temporary brackets to hold the splits while stacking, then banded them after stacking. This was an abject failure; by the time I went to fetch them, after the wood had dried, the bands were loose as a goose and stacks went to pieces. Tried several other iterations before coming up with this method. Wood drying and shrinking rarely affects the stability of the stacks and, rather than band, I simply use two ratchet straps, one on each half of the pallet, for transport; easy enough to just pull straps a click or two tighter if they start to loosen up while being moved. The process has reduced my wood handling, the most time & energy consuming part of the process, by 75%.

 

[maple1]

I am thinking this would do even better if a good layer of good plastic was put on the ground first, under the pallets. It is always giving up moisture. I suspect it would affect the lower layers more.

 

[jaoneill]

I am thinking this would do even better if a good layer of good plastic was put on the ground first, under the pallets. It is always giving up moisture. I suspect it would affect the lower layers more.

I actually did that under the first 2 pallets in this experiment. It seemed to make no discerable difference but probably because I used a 2 high pallet configuration. There were a few reasons for doing this. One being to get the wood further from the damp ground, another was visibility and ease of finding the fork cavity through grass or snow, a third being that I used older, compromised pallets on the ground hoping to get increased usage out of the newer ones that the wood is stacked on.

 

[Woodsplitter67]

A lot of experimenting with stacking the pallets over the last few years. Started with temporary brackets to hold the splits while stacking, then banded them after stacking. This was an abject failure; by the time I went to fetch them, after the wood had dried, the bands were loose as a goose and stacks went to pieces. Tried several other iterations before coming up with this method. Wood drying and shrinking rarely affects the stability of the stacks and, rather than band, I simply use two ratchet straps, one on each half of the pallet, for transport; easy enough to just pull straps a click or two tighter if they start to loosen up while being moved. The process has reduced my wood handling, the most time & energy consuming part of the process, by 75%.

The reduction of processing time is huge. Im showing my neighbor the ways of the wood he is now burning dry wood has a large shed getting ready to build a second shed and has two solar Kilns.. he has remarked to me how much nicer it is to burn sub 20% wood along with the reduction of Labor to do so

 

[maple1]

I actually did that under the first 2 pallets in this experiment. It seemed to make no discerable difference but probably because I used a 2 high pallet configuration. There were a few reasons for doing this. One being to get the wood further from the damp ground, another was visibility and ease of finding the fork cavity through grass or snow, a third being that I used older, compromised pallets on the ground hoping to get increased usage out of the newer ones that the wood is stacked on.

I also hate dealing with rotting pallets in any way shape or form. Nails everywhere. So at the bottom next to the ground I would likely put something else, like cinder blocks (what I actually do use) or maybe PT landscape tie things or maybe some short length of poles/logs. Even if the poles eventually rot (which they will), at least they won't be leaving nails behind.

Then again I think every tire on every wheeled thing I own has some kind of nail magnets inside....

 

[jaoneill]

I also hate dealing with rotting pallets in any way shape or form. Nails everywhere. So at the bottom next to the ground I would likely put something else, like cinder blocks (what I actually do use) or maybe PT landscape tie things or maybe some short length of poles/logs. Even if the poles eventually rot (which they will), at least they won't be leaving nails behind.

Then again I think every tire on every wheeled thing I own has some kind of nail magnets inside....

I try to get rid of the pallets before they get that bad....

 

[Jan Pijpelink]

I am using a solar kiln for the 2nd year, thanks to @Woodsplitter67. I agree, it works. My kiln is still up. I will be traveling till mid December and will take it down then. I have not take any MC measurements yet.

 

[jaoneill]

The reduction of processing time is huge. Im showing my neighbor the ways of the wood he is now burning dry wood has a large shed getting ready to build a second shed and has two solar Kilns.. he has remarked to me how much nicer it is to burn sub 20% wood along with the reduction of Labor to do so

I've been doing this for near 50 years and have always tried to improve the entire process. Started out burning almost 40 cord a year, built an air tight furnace that was one huge heat exchanger with an afterburn chamber and combuster to boot, that cut it down to 20-25 cord. Then put in oil boilers for the shoulder seasons; down to 18-20 cord. Then about 15 years ago did major improvements built a fireproof, masonry, block mechanical room off the house for the boilers and generator, pulled the twin oil boilers out of the basement, went to a wood gasification boiler and cut the usage down to 10 cord. We only heat eight of our 16 rooms most of the time, so this year I insulated the 1st floor ceilings over the heated space, should help cut usage a bit more. Have also experimented with numerous ways to cut down on the wood processing time and the above pallet method is the best I have found.

 

[Woodsplitter67]

I've been doing this for near 50 years and have always tried to improve the entire process. Started out burning almost 40 cord a year, built an air tight furnace that was one huge heat exchanger with an afterburn chamber and combuster to boot, that cut it down to 20-25 cord. Then put in oil boilers for the shoulder seasons; down to 18-20 cord. Then about 15 years ago did major improvements built a fireproof, masonry, block mechanical room off the house for the boilers and generator, pulled the twin oil boilers out of the basement, went to a wood gasification boiler and cut the usage down to 10 cord. We only heat eight of our 16 rooms most of the time, so this year I insulated the 1st floor ceilings over the heated space, should help cut usage a bit more. Have also experimented with numerous ways to cut down on the wood processing time and the above pallet method is the best I have found.

The less we handle the wood the better. I started saving labor by drying my wood in a shed insted of on racks and then moving to a shed or playing with tarps. Next was cutting tomes down on processing... i like getting the free wood.. makes me happy

 

[Cfran88]

I missed the original thread from Woodsplitter. I have a few questions for anyone that knows...

What kind of plastic are you using for the kiln? How long does it last before needing replacement?

Is there a door/entrance built in to add or remove wood? Or do you remove all the plastic them reapply it the next year after on a new batch?

Is there harm in keeping the wood in the kiln year round? Can wood be "too dry"? I was originally looking for a way to keep the wood dry (bought some wood and it's getting rained on, no skill to build a shed). Ended up having pretty wet wood burning tonight even though MM said it was ok (the amount of water cooking was shocking).

But I'm just starting to scrounge wood, hoping to never have problems after this year. Would love to start kiln drying before the spring rain really starts, maybe even a cord drying before the snow falls this year if I'm lucky.

Is it safe to say with kiln drying that I don't have to get years ahead with wood? I only live on 1.4 acres so I can only use so much space before it bothers my husband, but at least 3 or 4 cords. Plus since I'm a new scrounger, unsure how much wood I will actually get next year. We are just casual burners using an insert (unless wood turns out to be fruitful enough for me to turn down the furnace)

Any advice would be appreciated. Thanks!

 

[Jan Pijpelink]

I missed the original thread from Woodsplitter. I have a few questions for anyone that knows...

What kind of plastic are you using for the kiln? How long does it last before needing replacement?

Is there a door/entrance built in to add or remove wood? Or do you remove all the plastic them reapply it the next year after on a new batch?

Is there harm in keeping the wood in the kiln year round? Can wood be "too dry"? I was originally looking for a way to keep the wood dry (bought some wood and it's getting rained on, no skill to build a shed). Ended up having pretty wet wood burning tonight even though MM said it was ok (the amount of water cooking was shocking).

But I'm just starting to scrounge wood, hoping to never have problems after this year. Would love to start kiln drying before the spring rain really starts, maybe even a cord drying before the snow falls this year if I'm lucky.

Is it safe to say with kiln drying that I don't have to get years ahead with wood? I only live on 1.4 acres so I can only use so much space before it bothers my husband, but at least 3 or 4 cords. Plus since I'm a new scrounger, unsure how much wood I will actually get next year. We are just casual burners using an insert (unless wood turns out to be fruitful enough for me to turn down the furnace)

Any advice would be appreciated. Thanks!

I use 6 mill clear plastic. It stays on from mid June till late Oct./early Nov. Keeping it on all year would not harm, but in the winter it serves no purpose. Wood can be too dry, ideal is 12%-16% MC.

 

[Cfran88]

I use 6 mill clear plastic. It stays on from mid June till late Oct./early Nov. Keeping it on all year would not harm, but in the winter it serves no purpose. Wood can be too dry, ideal is 12%-16% MC.

Is your wood green when it goes in?

 

[jaoneill]

I missed the original thread from Woodsplitter. I have a few questions for anyone that knows...

What kind of plastic are you using for the kiln? How long does it last before needing replacement?

Is there a door/entrance built in to add or remove wood? Or do you remove all the plastic them reapply it the next year after on a new batch?

Is there harm in keeping the wood in the kiln year round? Can wood be "too dry"? I was originally looking for a way to keep the wood dry (bought some wood and it's getting rained on, no skill to build a shed). Ended up having pretty wet wood burning tonight even though MM said it was ok (the amount of water cooking was shocking).

But I'm just starting to scrounge wood, hoping to never have problems after this year. Would love to start kiln drying before the spring rain really starts, maybe even a cord drying before the snow falls this year if I'm lucky.

Is it safe to say with kiln drying that I don't have to get years ahead with wood? I only live on 1.4 acres so I can only use so much space before it bothers my husband, but at least 3 or 4 cords. Plus since I'm a new scrounger, unsure how much wood I will actually get next year. We are just casual burners using an insert (unless wood turns out to be fruitful enough for me to turn down the furnace)

Any advice would be appreciated. Thanks!

I would venture to say that a "kiln" can be as simple or as elaborate as you care to make it. I did mine on order of a simple, disposable way to get this year's wood dry enough to burn. Relatively inexpensive 4 mil poly sheeting that I will dipose of when it comes off the stacks. FWIW, poly, no matter the weight, will not generally last more than a year in the weather. I know this after a lifetime using it for assorted purposes from spring time greenhouses to temperary storm windows; the sun's UV rays render it extremely brittle after six to eight months.
One of my younger brothers went a more elaborate route building a combination woodshed, boiler shelter, greenhouse; a pole barn with fully half sided and roofed with polycarbonate panels. He stocks the woodshed portion in the spring and once he has moved all of his garden seedlings out, closes up the doors and most of the vents and "cooks" the wood at 130-150 degrees for most of the summer. Works extremely well and it is now almost ten years since he built it and it's still in great shape.

 

[Jan Pijpelink]

Is your wood green when it goes in?

Most of it. Well, not soaking wet, but not fully seasoned.

 

[Woodsplitter67]

Is your wood green when it goes in?

No.. do not put green wood in the kiln.. let it season for a few months.. its ready to kiln when the stacks start to shift is a good rule of thumb. If you want to do some reading look in my signature there are 2 links to the thread.. ill be finishing out the part deux thread this week.. just been to busy.. use the 6 mil CLEAR plastic from big box store.. or if your going to be doing alot go on line and get the greenhouse pladtic.. the plastic you get in the store will last like 3 months if your lucky.. the greenhouse stuff will last year's.. its more expensive but will last alot longer making it cheaper in the long run

 

[Woodsplitter67]

If your going to be doing a kiln on a regular basis you may want to put together somthing less basic than mine.. mine is simple.. i leave the racks there .. stack the splits..let it sit and then wrap it around june.. unwrap it in September and tarp it.. then burn it.. keeping it simple keeps the overall time spent on wood down..

 

[Woodsplitter67]

Is your wood green when it goes in?

If your looking for a different design than mine.. more of a walk in type look up @Poindexter .. hes is a more permanent style with great results.. he may have a link or may chime in and help you out

 

[Coalescent]

Hello all!

I updated my original post with the 90 day and 110 day performance of the first kiln, and the 80 day performance of the second kiln.

I also added a photo showing that my kilns are shedding snow nicely. It just falls right off. I love it!

Temperature
So far, even when it's in the low teens outside with wind chills placing the temps near 0dF (we've had a few days like this already), the kilns are warming above freezing if there's any sun on them. Since the cloudy days tend to be warmer, the kilns are still above freezing pretty much every day for at least some period of time.

Watching the temps plummet at night and warm to the 50s and 60s in the kilns during the day made me wonder if this freezing/warming action might help expel the water from the center of the splits... the water in these splits freezes hard every night, expanding, then warms well above freezing during the day, liquifying and shrinking again. No idea if this speed things along or not, but am trying to devise a way to test my theory.

Some interesting incidents that happened in the meantime--

Wind Damage
In mid-October we had an intense windstorm (60+mph gusts) that came in from an unusual direction. The wind ripped the plastic off my newer kiln, even with the shrink wrap and lots of staples in the bottom. I re-attached it, but am considering further reinforcement next year--possibly clamping the bottom 2" between two 2x4s. On the other hand, it wasn't very difficult to fix, and it's held strong since.

Windstorm Damage

Wildlife
I enjoyed snapping several shots of this fellow near the kilns late in September:

A Visitor

Snow Arrives

Kilns in the Snow

 

[Ihalmiut]

I'm doing this! I have 2 cords dry in the shed. My buddy brings me a cord of "dry 3 year oak". So its all stacked in front of my dry elm, oak, cherry. Totally not dry! So now I am going to split it some more, stack and wrap like this. I'm in Minnesota. Lots of snow already and have had some early really cold weather. Have you guys thought of black plastic?

 

[Coalescent]

Have you guys thought of black plastic?

I don’t have links handy, but I’ve seen numerous posts in my own research on these forums (and others) that suggest that black plastic does NOT work nearly as well as clear plastic.

I think the idea is that the black plastic might heat up from the sun’s energy, but it doesn’t transfer that heat energy to the wood underneath it. Clear plastic allows the sun’s radiation through, heating up the air and wood inside the kiln, but the radiation doesn’t have enough energy to escape—think of the greenhouse gas effect.

At any rate, I can say from personal experience that clear plastic works, and works well!

 

[Woodsplitter67]

I'm doing this! I have 2 cords dry in the shed. My buddy brings me a cord of "dry 3 year oak". So its all stacked in front of my dry elm, oak, cherry. Totally not dry! So now I am going to split it some more, stack and wrap like this. I'm in Minnesota. Lots of snow already and have had some early really cold weather. Have you guys thought of black plastic?

In essence you are creating the greenhouse effect. you are making a greenhouse and basically putting wood in it. there are no green houses built with black plastic you do not want to heat the plastic you want the sun's energy to transfer to the inside of the kiln

 

[Coalescent]

Is your wood green when it goes in?

One of the differences between my experiment and @Woodsplitter67’s kilns is that I was in emergency mode this year and needed to use and dry my own wood fast, because I moved recently.

Some of the wood I used was storm-felled and dead already, but most of it was very green—I felled the tree, bucked it, split it, and stacked it in the kiln. Most of this wood sat in the sun for a week or two before I wrapped the kiln, but that’s it. I think my use case is closer to @Jan Pijpelink.

I didn’t pre-season my wood before using the kilns, and they were started late in the season (August and September), yet I was still able to dry Red Oak from maxing out my moisture meter at 38-40% MC to sub-20% MC in 110 days.

I think this helps demonstrate that kilns work very well, even in less-than-ideal conditions.

 

[Jan Pijpelink]

One of the differences between my experiment and @Woodsplitter67’s kilns is that I was in emergency mode this year and needed to use and dry my own wood fast, because I moved recently.

Some of the wood I used was storm-felled and dead already, but most of it was very green—I felled the tree, bucked it, split it, and stacked it in the kiln. Most of this wood sat in the sun for a week or two before I wrapped the kiln, but that’s it. I think my use case is closer to @Jan Pijpelink.

I didn’t pre-season my wood before using the kilns, and they were started late in the season (August and September), yet I was still able to dry Red Oak from maxing out my moisture meter at 38-40% MC to sub-20% MC in 110 days.

I think this helps demonstrate that kilns work very well, even in less-than-ideal conditions.

I C/S/S my wood in February/March. It has been in sun and wind till I wrapped the kiln in June.

 

[Coalescent]

I C/S/S my wood in February/March. It has been in sun and wind till I wrapped the kiln in June.

I stand corrected! Thank you for replying.

When you replied to the question of “is your wood green when it goes in?” earlier and said “Most of it. Well, not soaking wet, but not fully seasoned.” I assumed you were doing something closer to what I was doing, not 3 months of seasoning.

Apparently my kiln experiment is fairly unique in that regard.

 

[Jan Pijpelink]

I stand corrected! Thank you for replying.

When you replied to the question of “is your wood green when it goes in?” earlier and said “Most of it. Well, not soaking wet, but not fully seasoned.” I assumed you were doing something closer to what I was doing, not 3 months of seasoning.

Apparently my kiln experiment is fairly unique in that regard.

Wood that has been C/S/S for 3 months is still wet, in my book.