Advice Needed on a Solar Kiln

Ok, here goes...I have an opportunity to get rather large amounts of green timbers at a very reasonable cost. The fellow will be cutting hard and soft maple, walnut, poplar and honey locust in the next few weeks. While I am going to let some of it air dry, I would also like to try to build a solar kiln, maybe large enough for 1000 bf.

The question being: Has anyone tried building their own...and how did it work out. Is it economical enough to build vs. the cost of hauling it off to a dehumidification kiln @ 35-40 cents/bf?

Even with the cost of the drying, it would still cost me less than a buck/bf. Hmmm, research, more research!

Thanks in advance for any input.

John

We have a member in our woodturning club who commercially solar-kiln dries wood. His set-up is simple. It is a south facing kiln about 20' wide, 10' high and 12' deep. The clear plastic sheeting streches from the ground up to the building. It is fastened at the outer side of the room (12' from the main wall) and angles back to the wall. He says that inside the room, it is always 75 degrees warmer (during daylight) than outside air temps. A small fan brings air in and there is an exit vent. He has a couple small fans to move air around inside. I believe a smaller version could be built quickly and cheaply.

Up in the north with the hassle of trying to keep the heat steady and control the moisture plus the cost of electric and building supplies. I just send mine to the local lumber guy. At $0.40 a foot it is just easeir to let him dry it. So if you want to try it have fun, but many kilns take a few month to dry the lumber enough to be used.

Its pretty hard to go wrong with a solar kiln. The best possible scenerio is that you you get a lot of lumber dried within about 45 days (I live in Maine) and life as a woodworker cannot get much better. Now keep in mind, because of the way a solar kiln works, you cannot over-dry wood with one of these things. That means even if the solar kiln is completely ineffecient, you have a great storage for your lumber needs. If its super effecient you get dried lumber and have great storage for your lumber needs. The point is, the two can be one!!

Now mine is pretty small. The angle of your roof should roughly match your latitude. Mine is a bit steeper than it should be, but still works. There are a slew of design details, too many to list in a post like this, but to answer your question, yes it is a very effecient way to dry wood. At the same time I FEEL anyway, that it is well worth building. I say that though because I have my own sawmill and can esily keep the kiln/ lumber storage filled to capacity for my woodworking needs.

I will leave you with a link to some air drying information on my website, and a picture of my solar kiln:

http://www.railroadmachinist.com/Wood-Drying-One.html