Home Made Kiln???

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Kind of a crazy idea, but you guys are used to that by now...

I have a 35,000 btu propane powered clothes dryer that is pretty much doing nothing. Its been rebuilt and is perfectly fine in every way, but my wife wants to keep her electric one for now.

So I got to thinking, what if you made a sheet metal box for this thing, mounting it to the front of the clothes dryer, remove the door and then load wood in it. If the thing works so good for drying clothes, why wouldn't it dry lumber? The big kilns often use natural gas or other fossil fuels to create the heat, and the internal blower would distribute the air flow...

The only problems I can think of is the timer. These things are made to run for 60 minutes max. Defeating the timer would be easy enough, but all the safety features for the burner tie into the timer. It would not be so easy to defeat as one would think???:dunno: The door shut off would be another safety kill switch to defeat, but that would be easy.

I don't know if turning the kiln on twice a day for 60 minutes (before work and after I came home) would be enough to dry the lumber or not. I supposed I could stick a dehumidifier in there to dry the lumber inbetween "firings", but I could do that without a 35,000 btu burner unit too though?:dunno::dunno::dunno:

Just a wild idea I had...
 
Travis,

If you build that, you've got to get it featured on the Red Green show... ;)

If you need a kiln, there's got to be an easier way! ;)

On the other hand, if you need a shop heater, it sounds perfect. Turn it on when you first go out there to take the chill off, let it run for an hour, and Bob's your uncle! ;)

Thanks,

Bill
 
I fear that what you would create would be an oven for quick drying and distroying woods. Too quick of a drying process is the distruction of wood. Cracks, checks, warps, & wanes is a result of quick drying.

Although a great home made kiln can be made using a simple dehumidifier in an enclosed area. I know one fellow who took an old truck Box, constructed racks on either side that would allow stickering of woods and in the center he placed a common room dehumidifier with a drain out of the enclosed area. In a few months he was able to bring the MC down to workable conditions. (I can't quote % numbers as I am not sure of the numbers and how long they took but he does have a simple yet effective home made kiln.
 
On the other hand, if you need a shop heater, it sounds perfect. Turn it on when you first go out there to take the chill off, let it run for an hour

The sad thing is, I was thinking about that. 35,000 btus would be just about right for my shop heater size wise. :)

Yeah the drying kiln might be a little to over the top. I have been thinking about building a small dehumidifying kiln in the shop though. I was thinking maybe hang it from the ceiling just to conserve space. Nothing big, just something to get the moisture content down from the solar kiln I now have. It would not be something you shove 500 feet of lumber into, maybe 75-100 bf for a certain project. I saw a guy on Fine WW do this I think and he got ready-to-use lumber in 7 days.
 
Travis, You would be better off finding a used dehumidifier and using that. I have one in the shop and does speed up the drying time a lot.
 
Dryer Timer

If you want a separate timer, put an timer extension cord to plugin the dryer, I'm sure there are 24 hour or 48 hr timers available(ie car plugin for block heater)
Irv
 
Travis, my buddy had a homemade kiln, painted it flat black, put three solar powered fans (from HF). Amazing how quickly the boards dried, happened a lot quicker with the fans, assume it is pulling the moisture out of the air. Worked here in Indiana both in winter and summer. Winter he shut the door, summer he left it open as it got extremely hot in there! Oh, saw something to do with heating and a manure pile in the last issue of Farm Show Magazine. Didn't think of you because of the manure, but because of the story! :dunno: :rofl: :rofl:
 
I do have a solar kiln at my house now. I would consider it about ½ built. That is, it can keep out water and does dry out the wood some, but if I insulated it, painted it black and did other things to tighten it up, it would work a lot better.

Unfortunately the arcyilic panels are set at too high of an angle for my latitude I think. I am not sure how much heat I lose by doing that, but obviously some. The same can be said for my trees that shade the thing. I am in hopes to cut these Hackmatack down this Spring or Summer.

The kiln is wired for both lights and outlets so theoretically I could toss a dehumidifier in there and help speedy up the drying process. I just started this post because I do have a 35,00 btu propane dryer that is doing nothing. Maybe I could use the heating unit out of that somehow :)

Here is a picture of my current "solar kiln". The storage aspect of it does work good because I pull my wood out of my kiln, put it on those white plastic barely visible in the picture and roll it right through the window onto my radial arm saw which is just inside the building. In this way I can cut 20 foot lumber despite having a small shop.

Drying_Kiln-454x341.jpg


Feed_Rolls2-452x334.jpg
 
Travis, having experience with greenhouses and that lexan material, you aren't holding any heat in once the sun goes down. That plastic/lexan is about a 1/2 R in insulating value. Two ways to hold heat in there, use a flat black wall of something, bricks or some material that will retain the heat and then put it back in the building as the sun goes down. Some greenhouses are experimenting with black 50 gallon plastic drums full of water. The theory is, during the day they absorb all of the sun's energy provided through the lexan, and at night they radiate it back into your kiln. To be best energy efficient, you need a canvas to pull to increase your R value and decrease your heat loss. In greenhouse terminology we call it a shade cloth because it also saves in the summer from the overheating of the sun through the lexan. I would almost bet you would get as good if not better results using steel/tin roofing painted flat black. That lexan stuff is expensive!
 
Drying wood

Right now logs are decked, butt ends coated if needed. Or just air drying under cover and stickered with 1x1 inch pieces cut with woodmizer. However the western red cedar is a special case. Our woodlot is in the West Bench near Golden, where in 1926, a big fire burned the west bench. We recently had to take out some cedar snags remaining from the fire, standing dead or partily alive since 1926. The cedar logs had center rot, or limb rob and were in danger of falling(kind of bad for hikers or mtn bikers). The outside is case hardened and knots so hard, the bandsaw hesitates when cutting. Beautiful wood and mighty fine for board and batten or bevel siding.
Here's an image of the early days of logging.
Have a Great Day
Irv
 

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Travis, having experience with greenhouses and that lexan material, you aren't holding any heat in once the sun goes down. That plastic/lexan is about a 1/2 R in insulating value. Two ways to hold heat in there, use a flat black wall of something, bricks or some material that will retain the heat and then put it back in the building as the sun goes down. Some greenhouses are experimenting with black 50 gallon plastic drums full of water. The theory is, during the day they absorb all of the sun's energy provided through the lexan, and at night they radiate it back into your kiln. To be best energy efficient, you need a canvas to pull to increase your R value and decrease your heat loss. In greenhouse terminology we call it a shade cloth because it also saves in the summer from the overheating of the sun through the lexan. I would almost bet you would get as good if not better results using steel/tin roofing painted flat black. That lexan stuff is expensive!

I bet you're right...

I really was not sure where to go with this project,so I kind of stopped. My wood is dry and out of the rain and therefore drying somewhat, but at some point I am going to need to get a more accurate way to get the moisture content down.

I got bigger fish to dry right now, so this project is still on the back burner, but at some point I am going to have to research a better way to make this work.

I was thinking maybe get a second layer of the lexan stuff and have two layers to help trap the sun better? :dunno: Maybe a dehumidifier on a timer might work to, so after the sun sets, the dehumidifier kicks in till sun-up. Again I don't really know. :dunno: I am open to any ideas though. The location works well, now if only I could get some super-dry lumber.
 
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