Home Made Kiln Questions

[joeythebutcher]

I decided to use the exhaust from my pellet stove to make a kiln of sorts. I ran a length od aluminum clothes dryer exhaust hose to a heavy plastic toy box with a lid that kind of slides up like a roll-top desk. There are plenty of gaps to vent and let air pass through.

It seems to be working great, I put a thermometer in there and it's well over 120 degrees in there, the thermometer only went to 120.

The questions are:

1. I'm getting some condensation in there.Is that ok or should I find some way of absorbing it ?

2. What happens when I turn my pellet stove off for the night and it freezes up in there ? Is that bad for the wood, causing splitting or something ?

3. How long would it take wood that has been air-dryed for six months or so to cure proprerly.

Thanks for the Help

Joey

[AlArchie]

Joey, one of the by products of combustion is good old H20. If the wood or the interior of your box is cooler than the exhaust, you will get condensation. Burning most wood based fuel releases, as by products, carbon dioxide, carbon monoxide, unburned particles (soot) and water vapor, so all of these are surrounding your wood.

You could build a heat exchanger and pipe the heated air into your kiln...that would eliminate the vapor problem, but short of that, I don't see how you could dry the exhaust.

I'd want to get an accurate temperature reading in that box, too. How much above that 120 degree mark is it getting? Is there enough heat to deteriorate or ignite the plastic in the box. Some plastics can take the heat and others can't.

During the cool down process, you may be adding moisture to the wood and that could cause some freeze splitting...that's pretty iffy, if you ask me.

The general rule for air drying is to allow one year per inch of wood thickness. If you are going to dry whole logs, no matter what you do, you will most likely experience splitting along the whole length. Waxing or otherwise sealing the end might prevent that but with full diameter logs, even that is questionable.

If you rip the logs into dimensioned lumber, seal the ends, sticker and stack the pieces and air dry, you will have some sucess.

Smaller diameter sticks (1" to 2") can be air dried if you seal the ends and put the sticks in a dry environment. Try doing some with the bark on and some with the bark removed and see which works for you....varying opinions on this step.

Al