# My Hillbilly solar kiln test



## Babaganoosh (Jul 29, 2015)

I've got an 8 foot by 4 foot single stacked bunch of black locust that I wrapped in some shrink wrap. Didn't do the bottom. It gets sun most of the day.

It's 86 degrees out right now and my probe thermometer is showing approximately 135 degrees.


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## Z33 (Jul 29, 2015)

I like the idea but I feel like the moisture needs a way to escape out the top...


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## Big Chris (Jul 29, 2015)

I'm very interested in how this works, did u measure the moisture content before ?


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## Jan Pijpelink (Jul 29, 2015)

Well, at 135 F during day time the moisture needs a way out to evaporate (upwards). Having it not wrapped at the bottom is good so it can drain out when it is cooler at night. So punching some holes in the top might help.


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## Babaganoosh (Jul 29, 2015)

I've got some maple that's in one that I've measured the moisture content. It doesn't get as  hot because it's not getting full sun. 

You would think you want holes in the top but apparently they aren't needed. Guys on another site have done this and weep holes in the bottom or not covering the bottom gets enough moisture out when it condenses and runs down the side to be effective. I'm sure it could be tweaked to make it better but a simple wrap job like this makes a big difference and doesn't require much time.


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## maple1 (Jul 29, 2015)

Looks like some condensation on the plastic? So that should run down & out the bottom.

Be interesting to see the results.


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## Jan Pijpelink (Jul 29, 2015)

Think I will try it too.


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## Babaganoosh (Jul 29, 2015)

maple1 said:


> Looks like some condensation on the plastic? So that should run down & out the bottom.
> 
> Be interesting to see the results.





maple1 said:


> Looks like some condensation on the plastic? So that should run down & out the bottom.
> 
> Be interesting to see the results.




Yeah, it runs down the sides and out the bottom. 

If you tack some scrap wood on the sides so the shrink wrap doesn't touch the fire wood it keeps the condensation off the firewood totally.


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## xman23 (Jul 29, 2015)

We would all like to see a test. Here's what I would do. With a few sample splits of the same wood and age. Label and weigh each piece. Put some in the plastic tent and some outside. Expose each to the same sun for the some time. Weigh each split again, and post the results here.


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## Babaganoosh (Jul 29, 2015)

xman23 said:


> We would all like to see a test. Here's what I would do. With a few sample splits of the same wood and age. Label and weigh each piece. Put some in the plastic tent and some outside. Expose each to the same sun for the some time. Weigh each split again, and post the results here.



If you Google around a bit you will find it. Someone has done just that. Moisture content and weight.


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## Soundchasm (Aug 1, 2015)

Babaganoosh said:


> I've got an 8 foot by 4 foot single stacked bunch of black locust that I wrapped in some shrink wrap. Didn't do the bottom. It gets sun most of the day.
> 
> It's 86 degrees out right now and my probe thermometer is showing approximately 135 degrees.
> 
> ...



Man, you know this thing is going to work.  Once that moisture has cooked out of the wood, I'd be hard pressed to imagine a scenario where its going to go back INTO the wood.  None of my storage spaces have access to full sun or I'd be all over this.

The bit of data I'd be interested in is how big a split needs to be before this isn't as effective.  What if you only had to split the wood half as much as you do now?  And the follow-on would be if it works as well on a (say) 3" round as a 3" split.


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## Babaganoosh (Aug 2, 2015)

One thing I did notice is how much the wrap keeps the heat in. At 530 this morning the probe said it was 82 inside the wrap. It was only 64 outside. The sun hasn't been on it for about 8 to 9 hours at that point.


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## Oldman47 (Aug 3, 2015)

An observation on another forum was that for very green wood the kiln slowed things a bit by restricting air flow, but after a short drying period, when the easy moisture was gone, it seemed to help.


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## BoiledOver (Aug 3, 2015)

xman23 said:


> We would all like to see a test. Here's what I would do. With a few sample splits of the same wood and age. Label and weigh each piece. Put some in the plastic tent and some outside. Expose each to the same sun for the some time. Weigh each split again, and post the results here.


Or you could do that very test yourself.


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## Babaganoosh (Aug 3, 2015)

160 at the top today and 140 in the middle.


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## owingsia (Aug 6, 2015)

Ok I am curious how fast does this speed things up? My stacks are in full sun year round.... Would this make is possible to have fully ready wood in one summer? I mean we burn 7-8 cord a year... you know what that means in terms of 3 year wood stacks? If I could cut that back to just 2 years of wood needed (one drying for use and the other sitting for "Just in case")


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## begreen (Aug 6, 2015)

Yes, you can accelerate wood drying by increasing the surface area (smaller splits), temperature, lowering the humidity and/or a high volume of air flowing over the wood. This is what kiln drying is about and why stacks dry out quicker if they are in the sun with the prevailing wind blowing through the stacks. 

We hare having a very sunny and dry summer. I am seeing split madrona and cherry dry out very quickly in these conditions.


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## cptoneleg (Aug 7, 2015)

Babaganoosh said:


> I've got an 8 foot by 4 foot single stacked bunch of black locust that I wrapped in some shrink wrap. Didn't do the bottom. It gets sun most of the day.
> 
> It's 86 degrees out right now and my probe thermometer is showing approximately 135 degrees.
> 
> ...


Like making it rain on your wood every day  This one should be in a place called STUPID


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## Jan Pijpelink (Aug 8, 2015)

cptoneleg said:


> Like making it rain on your wood every day  This one should be in a place called STUPID


Another member is doing an experiment and posting his findings on this forum. Why your harsh reaction to this?


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## blades (Aug 8, 2015)

cptoneleg said:


> Like making it rain on your wood every day  This one should be in a place called STUPID


 You have failed to understand the process the wood is not wrapped tight there must be a standoff of the wrap from the wood to allow condensation to collect at the top and drain down the sides ( like a triangle or Cone). It does work, additionally the heated wood  loses heat quite slowly in comparison to the rather rapid rise and fall of the external conditions. At the moment I have apx 2/3 of cord of marginal wood in my small garage - it is in the high 60's out right now  but still close to 80 Inside. This with a 30 inch screen door. I use a fan just to move the air around and get some exchange through the screen door. Days that are at least mid 70's with Sun will have the interior of the garage at 100+ or more.  I can feel the difference of humidity in and out the first few days of a new stack being placed in there. Of course days that the external humidity is way high slows the process, but no more than a conventional stack sitting outside in the elements.


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## velvetfoot (Aug 8, 2015)

I like the idea of shrink wrapping a stack just so it won't fall over, lol.


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## Ashful (Aug 8, 2015)

velvetfoot said:


> I like the idea of shrink wrapping a stack just so it won't fall over, lol.


True, but that could mean miles of plastic, for a lot of us.  Not the greenest solution to a problem.


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## KenLockett (Aug 8, 2015)

velvetfoot said:


> I like the idea of shrink wrapping a stack just so it won't fall over, lol.



or for holding tarps on top so they don't blow off.


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## Babaganoosh (Aug 8, 2015)

It seems to be working but time will tell.


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## owingsia (Aug 8, 2015)

sorry to keep asking this.... What is the estimated time for wood to be ready? I mean will this say make a cord of wood (Not oak, but mixed hard woods) ready in say 6 months, or will it be like 3 months less time so 20-21 months instead of 24? I guess what I am asking is is the estimated to speed things up drastically? Like could I take my Cherry that is probably going to be ready next spring and get it ready for this Jan-Feb? Would love to have an extra 2 cord of Cherry ready by then.... last year used up our back up reserves etc...


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## Oldman47 (Aug 8, 2015)

owingsia said:


> sorry to keep asking this.... What is the estimated time for wood to be ready? I mean will this say make a cord of wood (Not oak, but mixed hard woods) ready in say 6 months, or will it be like 3 months less time so 20-21 months instead of 24? I guess what I am asking is is the estimated to speed things up drastically? Like could I take my Cherry that is probably going to be ready next spring and get it ready for this Jan-Feb? Would love to have an extra 2 cord of Cherry ready by then.... last year used up our back up reserves etc...


It is the question we are trying to answer with the experimental stacks that people have.


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## Babaganoosh (Aug 8, 2015)

I think you missed the boat for this year, the burning season is almost here and the prime months to do it are summer time. I don't think wrapping anything up today will have it ready for this season. 

That being said, if it's not going to be ready for this season anyway you could always try it and see what happens.


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## owingsia (Aug 8, 2015)

Oldman47 said:


> It is the question we are trying to answer with the experimental stacks that people have.




ah ok. I am very curious about this.



Babaganoosh said:


> I think you missed the boat for this year, the burning season is almost here and the prime months to do it are summer time. I don't think wrapping anything up today will have it ready for this season.
> 
> That being said, if it's not going to be ready for this season anyway you could always try it and see what happens.



Maybe. I think I will join in and see how this goes. 

I mean its not like the wood was going to be ready and as I am reading this... we have good warm days here in Virginia well into November. I have Aug, Sep, Nov, to see how things go. 

Heck if I can get wood ready or dang near it that would be great. 

I am also curious how well it will work once the temps start to drop. If I can get temps into the 60s on a cool December day that would be a +.


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## Ashful (Aug 8, 2015)

owingsia said:


> sorry to keep asking this.... What is the estimated time for wood to be ready? I mean will this say make a cord of wood (Not oak, but mixed hard woods) ready in say 6 months, or will it be like 3 months less time so 20-21 months instead of 24? I guess what I am asking is is the estimated to speed things up drastically? Like could I take my Cherry that is probably going to be ready next spring and get it ready for this Jan-Feb? Would love to have an extra 2 cord of Cherry ready by then.... last year used up our back up reserves etc...


In a true kiln, oak (firewood splits) will dry from 52 to 20 MC% in 260 hours (11 days) at 140F.  I know one who has achieved similar results stacking in the hot attic of a barn in summer.  So, yes, you can shave the time to season very dramatically, if you get things dialed in right.

This 'kiln' is not dialed in right.


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## begreen (Aug 8, 2015)

Cherry dries pretty quickly. If you can increase the temperature and airflow through the stacks you might get burnable wood in January. Got an empty greenhouse with a fan?


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## cptoneleg (Aug 8, 2015)

blades said:


> You have failed to understand the process the wood is not wrapped tight there must be a standoff of the wrap from the wood to allow condensation to collect at the top and drain down the sides ( like a triangle or Cone). It does work, additionally the heated wood  loses heat quite slowly in comparison to the rather rapid rise and fall of the external conditions. At the moment I have apx 2/3 of cord of marginal wood in my small garage - it is in the high 60's out right now  but still close to 80 Inside. This with a 30 inch screen door. I use a fan just to move the air around and get some exchange through the screen door. Days that are at least mid 70's with Sun will have the interior of the garage at 100+ or more.  I can feel the difference of humidity in and out the first few days of a new stack being placed in there. Of course days that the external humidity is way high slows the process, but no more than a conventional stack sitting outside in the elements.



Carry on-- there have been many many  post on how to cure, season wood faster, the fastest for the average wood burner is -- single stacked, wind, sun cover top only if you want and time depending on type of wood.  I burned lots of 6 month css wood and stayed warm my stove did not know the difference and neither did I until I found this site.

And now I rotate into a woodshed and burn 3-4 year old wood only and yes I stay warmer burn less wood and have about 4 years worth now and I work full time and am 67 years old.  Put your big boy britches on. Boys and Girls


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## BrotherBart (Aug 8, 2015)

When you first burn three year air dried wood it will be like the first time you had sex. You will want to kill yourself for what you have been missing.


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## brenndatomu (Aug 9, 2015)

owingsia said:


> sorry to keep asking this.... What is the estimated time for wood to be ready?


The preliminary reports that I have been hearing are saying 2 months in full summer sun, I don't recall what wood species that was though...


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## JTRock (Aug 9, 2015)

One frustrating thing about my property is its bordered by trees so to get sustained sun I would have to stack in middle of my yard. 

Last year I was greatly concerned with less than dry wood from a supplier that I was not to happy with, I needed wood in the 18"-20" and ended up with 22"-24" huge chunks that fit corner to corner in my stove. But from August right up to November it ended up drting decently and burning fine without sizzling and steaming. Occasionally I would throw some wood bricks in with the chunkier ones.

This year got 16-18" and should be good. Wish I had more sun to speed up the process


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## brenndatomu (Aug 9, 2015)

cptoneleg said:


> Like making it rain on your wood every day This one should be in a place called STUPID


Except for...it works! 
If you google the test on that other site you'll find that the condensation goes away for the most part after a few weeks, at least the heavy condensation. The other factor that plays in here vs a wood stack being rained on everyday is the temp. 140* (plus) internal temps changes things


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## maple1 (Aug 9, 2015)

cptoneleg said:


> Carry on-- there have been many many  post on how to cure, season wood faster, the fastest for the average wood burner is -- single stacked, wind, sun cover top only if you want and time depending on type of wood.  I burned lots of 6 month css wood and stayed warm my stove did not know the difference and neither did I until I found this site.
> 
> And now I rotate into a woodshed and burn 3-4 year old wood only and yes I stay warmer burn less wood and have about 4 years worth now and I work full time and am 67 years old.  Put your big boy britches on. Boys and Girls



That's great - but situations differ for different people. There are two factors that are in your process that some might not have enough of at some point - time, and space. I do as you, as I am lucky to have the space and am a couple years ahead on time (although I've taken most of this year so far off - time to get at it).  So adding some kiln effect when you don't have the space for 4 years of wood or are just getting at it so you don't have 3 years to wait for it or are sheltered from the wind - well, nothing wrong with that, and hardly stupid.


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## Babaganoosh (Aug 9, 2015)

Yeah ideally just stack and let it sit. However I have access to lots of shrink wrap and I get out of work at 1pm. I've got a lot of time on my hands. I'm also a tinkerer  by nature so I've really got nothing to lose.

I think this would help the people who have wood that's borderline for an upcoming season. It might drive out that extra   moisture  and  put the wood into the shed this year versus next year.

I think it's also good for 1st and second year burners. It will give them that edge on getting  ahead.

I will add that I've cut a few small vent holes near the top to  let out some extra moisture and water vapor. Probably   lose a bit of heat but it will get more moisture out during the day.


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## BoiledOver (Aug 16, 2015)

@owingsia

Maybe you can find a more suitable answer to your question by researching over the internet. This is not a new concept and has proven an effective one. Is it effective enough to meet your standards? I don't know but if I were in a bind, I would throw one together and go for it. If you are not able to stockpile a rotating 3-year supply, this might be a viable solution for you. I have an old portable garage frame sitting here that I would use if need be and know from experience that it will hold 4 chords. It is the small one that Harbor Freight used to sell.

I have some aspen here that I downed in February 2015 and it is now ready for this season, just been sitting in the open. No matter the specie, if you split it small enough it will season more rapidly than if you go large.


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## turn_n_burn (Aug 19, 2015)

This is one of the coolest ideas I've seen. A small top vent should work wonders.


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## brenndatomu (Aug 20, 2015)

turn_n_burn said:


> This is one of the coolest ideas I've seen. A small top vent should work wonders.


I believe a top vent was tried and it actually slowed drying due to lowering the kiln temps


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## Babaganoosh (Aug 20, 2015)

I put 2 small ones in on each end. It's definitely not getting as hot. 

However there's almost zero built up condensation.


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