I'm thinking about building a small wood kiln

[motolife313]

im thinking 4x4x4. I'm guessing it needs a fan. Thinking of running it off a oil burning stove or propane. Anyone ever make one? Any idea how long wood takes to season?

 

[svk]

I might suggest larger like a whole cord? You'll hardly lose any heat by sending air through an area that small.

 

[motolife313]

Good idea. A whole cord at once would be nice. Be nice to insulate it. Maybe I could even build it out of plywood to keep cost down but would be a fun welding project to make it out of 1/8" steel

 

[svk]

I guess the other question is how much energy/fuel is going to be used to dry a cord of wood? Is it worth the cost?

 

[ChoppyChoppy]

It will need to be insulated for sure. I'd expect 2-4 weeks to dry a cord of wood, all depending on air temp.
It costs about $500 to run a load through the kiln we have. I've never tried to do firewood though, it's used for lumber. It's about 16ftx20ft, 12ft tall.

 

[motolife313]

If a pic helps here it is lol

 

[motolife313]

Wow a month is too much time for my patience. I was hoping a week or less at like 250 degree. Maybe not worth it and I just need to build a nice wood shed. My wood gets wet somtimes under the tarps

 

[svk]

I've heard of smaller kilns with good airflow drying things out in 48 hours.

 

[ChoppyChoppy]

I'm not sure what the picture of the little wood stove with golf cart tires is supposed to be? How do the tires not melt?

250?! I've never heard of a kiln being that hot. More like 100-120*. If you dry lumber too fast it ruins it. Case hardening, cracking, warping, etc. Usually don't want to get over 140*.

Of course firewood doesn't matter, but it takes way more energy to keep a building at 200* than it does at 100*.
Heat is part of it, but air movement and humidification is a big thing as well.

Like I said, I've never tried to dry firewood, it's just not cost effective.

We do have a solar kiln kit to build. I've been thinking of putting it up (have had it for probably 20 years haha). It'd be to dry firewood for bundles. The only cost would be a bit of power for the fans, but that wouldn't be too bad.

 

[chucker]

its a waste of time and the energy on both labor/fuel costs in a small scale op... big time, like a semi load at a time and being sold before it's dried to a 10% moisture content .... with out it being sold right out of the oven, its moisture goes back up to the ambient % of moisture in 2 to 3 days (uncontrolled storage).... shrink wrap vacuum packed would be the only viable option for short term open air storage.. good luck making a profit!

 

[chucker]

working part time in the local paneling mill pine, ash & popular v groove tongue an groove. it was always suggested to let all wood paneling set in the area it was to be applied to for 3 days to acclimate to the rooms moisture % before hanging at a 10% moisture content after milling..

 

[motolife313]

Ya I think 250 is a good number to use and dry the wood at. The fire box has 2300 white insulating brick in it. It's my smoker. Pics help get the ball rolling

 

[Streblerm]

If you are going to use oil or propane to dry wood for heating, why not just cut out the middleman and burn oil or propane for heat?

It’s why I refuse to pay money for firewood. I figure if I’m paying I might as well pay for something that loads itself.

 

[DFK]

Have you considered getting a small, steel shipping container?
Cut in a few air vents, paint it black, place a fan inside and set it in full sun.
Such a set up would dry firewood quite well.

David

 

[Pcoz88]

burner that burns used motor oil!?!?

 

[Sandhill Crane]

Check with local refrigeration contractors that do grocery store remodels/builds. They often remove walk-in cooler/freezers. The ones I've worked on are built with insulated foam panels skinned with light gauge metal. They cam lock together, and are easily built and taken apart. Although they are sealed with ???? a mastic(?) not silicone or latex caulk. It seals but does not set up. It can be scrapped off and cleaned up with WD-40. Panels can be cut (use eye, face, and breathing protection) and butted together if necessary by adding a metal lap joint, or corner angle inside and out, on the skin. For widths wider than one panel span structural steel columns and beams will be necessary.
Contractors generally trash used panels, and fill dumpsters rather quickly. You would most likely be doing them a favor asking for them.
Also check Ebay and you will get an idea of what I'm talking about. Panel sizes and thickness varies. Smaller freezers often include floor panels with diamond plate.
Also look through the glass doors of the milk section at the larger grocery stores where the gallons of milk are still on bossy carts pushed up to the glass doors. This will give you an idea of what I'm talking about.
If dealing in used panels you will want your shots up to date, including hepatitis.

Edit: Mastic is the wrong word.
Butyl caulk (spelling ?)

 

[lknchoppers]

Look at some commercial firewood kilns to get an idea of the temp/time you will need to heat the wood. I think 250*F for 24 hours should be more than enough with some air flow.

This link has some info:

http://www.kiln-direct.com/content/faqs_firewood/index.html

 

[dave_dj1]

Solar for the win. Have one side of the box clear and facing the sun. You will still need some air circulation.

 

[firefighter938]

I will second the solar kiln idea. You could easily and cheaply make a greenhouse type shed and fill it with wood. Only expense would be a small fan to move moisture out of the building.

 

[Woody912]

Depending on your species of wood you will need to decrease the total wt by about 1/2 to have dry wood. According to my quick and rough numbers it takes 100 btu's to vaporize 1# of water after you raise the temp to 212 F. There are 91,000 btu's in a gallon of propane and heat loss is inevitable because you will have to have circulation to removed water vapor. Unless you are selling bundles for $20 I do not see a way that this is profitable.