Small kiln for drying wood chunks

This was my project for today, its a realy simple design and it seems to work quite well.
First l started with the base (the burner)

then l made 2 chimeny holes in the drying drum

inserted the chimeny pipes

filled up with wood and put a lid on

light a small fire

and when the barrel got to temp lots of steam started to emerge

l’ll see what the wood chunks look like when they cool down tomorow. The goal of this aparatus is to be able to make green wood chunks as dry as possible as fast as possible, the airdrying seems to hit a stop at this cold, wet months so this is my idea to fight that. l can dry enough wood in here to get me about 350 km (220miles) of driveing. Hope you guys like it!


May I suggest 3 things:

  1. Ventilation
  2. Ventilation
  3. Ventilation

Air slots low and high will let the expanded air carry away moisture far faster and fuel efficient than pressure boiling it off.


I agree but be sure that you can seal the holes as for sure the inside bottom wood will ignite


Just a little insulation on the outside of the drum , and you have now a great charcoal retort :grin:


Kristijan, if you would put a little insulation around the barrow it would make it more efficient holding heat inside to dry the wood . Good job I want to build one for doing my wood if it works. Keep use posted on this one. Thanks

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I always wanted to build a solar kiln, you could easily add supplemental heat from a small rocket stove.

Don’t let the wood get too hot, or it will all catch on fire.


JO, this is the next step. But first l wanted to make sure there is not enough heat on the bottom to catch the wood on fire (like Michael sayd). I am planing to make a mantel around the kiln to catch the heat radiated from the outer wall of the heater.
I was allso thinking to make the chimenys suck the steam from the top, adding more suvzion to the drying barrel. The goal here is to dry wood below 10% moisture to have less problems with the gasifier when the real cold presses on our land, and allso to give a hatchet s litle brake :slight_smile:


With steam pipes slightly bigger dia and hight over barrel top, surrounding the smoke pipes, you would get air draft big time. Both heat and ejector effect. A layer of gravel or concrete in the bottom of the wood barrel will prevent fire and accumulate the heat to last during night.

Haha, tell me about it :wink:


JO, l was thinking somewhere in that direction (chimeny effect) but the gravel idea is genious! I have some peaces of firebrick left over from my summer kitchen build, shuld be great for accumulating heat! Thanks!


Hi Kristijan, do you have a up date on your trying kiln, now the winter cold has set in. Did you use the fire brick or gravel in the bottom to store heat?


Hi Bob,

Yes, l have cast about 5" thick layer of plaster on the bottom. I made chanals in it for the air to pass trugh, heating it and then passing trugh the bed of wood.
I still have to insulate the outer shell.
Ill post pictures later


I don’t mean to be impatient, did you ever get pictures? :slight_smile: I’m curious how this worked for you and what revisions you may have made.

Hi Bill!

I made a few batches with greenwood chunks, and it worked ok, but l found it faster and easyer to make pucks of my 4 year old oak firewwod and split with a hatchet. Now l made a fast rebak chunker and will most likely never use the kiln for green chunks again, unless maybe to make kild dry extra premium chunks out of airdry ones.

Its a good diy kiln, simple and effective, but it culd be greatly improved!


How long did it take for a batch? Approximately how much weight in a batch?

Chris that solar kiln is on my project list. I always seem to be behind on my winter wood and one of those would be a big help. Plus I need to get my saw mill setup so I can fix the barns up. I have looked at those plans several times and thought man that is soo simple.
I also like the idea of solar hot water from a pex collector that is on that same site. They both look like a good project.

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One batch dryed in a day. Its a 55gal drum, so a WAG of about 100 pounds a charge of dry wood. And a few bits of wood to burn underneeth.

JO was right. Ventilation is important. As well as insulation. This sistem lacks a layr or heat insulation on its outer shell.
Its not something l wuld do on a regular basis, but for a fast emergancy suply of wood, it works.
I think solar kilns wuld perform better, well, depends on where you live :smile:


I have never kiln dried wood, but I have done a lot of drying of other things----fruit, vegetables, meat, coffee beans, rice etc…In my experience, heat is only there to extract the water from the medium you are trying to dry (and to move air). The more important part is moving air, the drier the air the better. If you only extract the water from the wood with the heat but don’t allow/force it to leave quickly it will slow the drying process significantly. Move lots of air…Let it escape.


I know a guy who used it at a sawmill, it worked good. The larger problem is that in order to kill the bugs in the wood, you have to have a log of the temperature was maintained for a certain amount of time if you are going to sell it as lumber.

I told him to put it in the solar kiln. Get it dried out, then put it in his other kiln to get the log. Once the moisture is out, it shouldn’t take nearly as long or use as much energy. I don’t know if he did that or not. probably not. :slight_smile:

You don’t need much more then hoop house (greenhouse) construction to get most of the moisture out if you can get some airflow.




well airflow and low humidity air. :slight_smile:

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