Mini log kiln

[Acerforestry]

Ok, so I don't have the space to site a steel container to convert to a log kiln, in fact as I only only shift a limited amount of firewood I wouldn't really have the need for one I guess. But I'm curious, would an old domestic heating oil tank convert into a mini log drier (I'm going to avoid the word kiln now as it may not be properly applicable). I'm only really proposing that if at least it stripped at least some of the moisture out of green-ish cord it might be a worthwhile idea as there is an abandoned tank at my yard; take an angle grinder to one of the side walls to form a hinged door, weld a mesh floor in a few inches high. Drill some ventialtion holes and do a makeshift chimney. Finally put a small log stove in one end that can run on dried waste. There wouldn't be room for fans but is there any reason why that couldn't work at least to a degree? If i'm at the yard on and off for hours some days anyway it wouldn't be a hardship to keep feeding the stove.

[pie eater pete]

I have similar thoughts...i always sell out of hardwood and nobody will touch softwood locally, my thinking was a small shed with capacity for 8 IBCs and a small stove in the corner fed on softwood, obviously its not 100% airtight but fairly sure it will be quicker than left outside in U.K climate?

[openspaceman]

1 hour ago, pie eater pete said:

obviously its not 100% airtight

The last thing you want is airtight as you need to vent the moisture. The problem is how do you get the most moisture removal for the heat you put in and generally that;s why you need to circulate the air in the container and  dump a portion of moist air at a lower temperature than the temperature in the kiln.

[doobin]

Every bit of handling comes off your bottom line. I can't see how this on such a small scale would be viable. Also, cord won't dry that well (not sure if this was what you meant)- it really needs to be cut and split.

[Acerforestry]

I'm using the term incorrectly, if we are to be pedantic (don't take that the wrong way!) - I mean a few cubic metre bags of processed hardwood. split (that has just come in, as cordwood). I disagree that smaller quantities can't be beneficially lowered in moisture a a damn sight quicker than any other way other than a proper log kiln will do - my storage space is limited and arb arisings / the odd birch from coppicing come up frequently through the winter, and we don't all have huge yards. If you want said wood to be gone this season, how else are you going to do it? I don't have any covered storage other than one end of a polytunnel, so i will give this a shot. And I reckon it will work

[openspaceman]

1 hour ago, Acerforestry said:

And I reckon it will work

That depends on how you define "work"; yes there will be some drying but the efficiency of heat in verses water loss may be low.

 

You can go between the extreme of blowing ambient air through the box of logs to not blowing any air and heating the logs to ~120C, both will dry the logs, the first in months and the latter in 24hrs but neither will be the most energy efficient.

 

We measured our efficiency in terms of heat supplied against the theoretical latent heat of water removed, we didn't monitor the electricity the fans consumed. With the high temperature kiln we were about 50% efficient by our definition, I reckon one could do much better.

[Squaredy]

The real solution is to get people buying softwood.  Maybe we should stop using the terms hardwood and softwood with customers, because all they hear is good and bad.  The point is the softwoods are so much easier (and therefore quicker and more economical) to dry.  And some of the softwoods are easily as good as most hardwoods.  Larch is fantastic.  Dries really easily and burns long and hot.  Not many hardwoods can match Larch overall.

 

I have had some success selling Larch firewood it has to be said.  I sometimes think we should say Larch is hard wood.  That would not be a lie - Larch is a hard wood.  It is just not a hardwood.

[Woodworks]

On 24/11/2019 at 20:59, Acerforestry said:

Ok, so I don't have the space to site a steel container to convert to a log kiln, in fact as I only only shift a limited amount of firewood I wouldn't really have the need for one I guess. But I'm curious, would an old domestic heating oil tank convert into a mini log drier (I'm going to avoid the word kiln now as it may not be properly applicable). I'm only really proposing that if at least it stripped at least some of the moisture out of green-ish cord it might be a worthwhile idea as there is an abandoned tank at my yard; take an angle grinder to one of the side walls to form a hinged door, weld a mesh floor in a few inches high. Drill some ventialtion holes and do a makeshift chimney. Finally put a small log stove in one end that can run on dried waste. There wouldn't be room for fans but is there any reason why that couldn't work at least to a degree? If i'm at the yard on and off for hours some days anyway it wouldn't be a hardship to keep feeding the stove.

I have considered something similar. My plan was to build it tall and have the stove under the wood and a vent at the top and bottom to allow convection to create a through draft. Still never tried it though.

[SbTVF]

The real solution is to get people buying softwood.  Maybe we should stop using the terms hardwood and softwood with customers, because all they hear is good and bad.  The point is the softwoods are so much easier (and therefore quicker and more economical) to dry.  And some of the softwoods are easily as good as most hardwoods.  Larch is fantastic.  Dries really easily and burns long and hot.  Not many hardwoods can match Larch overall.
 
I have had some success selling Larch firewood it has to be said.  I sometimes think we should say Larch is hard wood.  That would not be a lie - Larch is a hard wood.  It is just not a hardwood.

Fully agree. I prefer Larch over anything other than beech or hawthorn actually. It absolutely belts out the heat!

And christ its so much better to process!

Starting to shift a bit this year, it dries so much better in the kiln even from fresh felled too.

[Silverhooker]

I burn mostly larch with odds and sods of syc and beech. Larch is great in a stove, dries and processes easily and round my way there is plenty.