Solar Kiln Progress

[JackLeg]

Thought I'd post a couple pics of WIP on my solar kiln. So, here they are:

Floor assembly & front wall



End Walls



Progress is slow, but steady. The floor is insulated to R-11, per VT's "plans." Their plans are pretty much just some sketches of the pieces needed to build a kiln, not real dimensioned plans.

Thanks for looking. :biggrin:

 

[woodArtz]

Why didn't you get more done today? :wwink: (sorry)

 

[JackLeg]

We're on target time wise. Now comes the fun part, the rear wall and two 6" doors. Then we stick on the polycarbonate top and we're ready to ruin some good wood!

 

[jeff...]

We're on target time wise. Now comes the fun part, the rear wall and two 6" doors. Then we stick on the polycarbonate top and we're ready to ruin some good wood!

Reggie good progress on the solar kiln, please continue to keep us posted. I'm really wanting to see someone be consistently successful with a solar to encourage the rest of us folks to give it a try.

Thanks

 

[Robert Arrowood]

Looks good!:thumbs_up I've been thinking about the soler power. I was wondering if you could get a couple of 12v auto fans.You could hook them up to a battery with soler charge.That way you would be totaly soler.Of course you would need to put them on a thermastat.Just wondering if it would even work?

 

[JackLeg]

Since I have electric power at the site where I plan to locate the kiln, I'm going with the 3 box fans. If I had access to a solar collector at a steal, I'd give it a try. I may install a humidistat as well. I plan to discuss this a lot more with Scott once I get further along.

This is all a learning experience for me. I plan to attend a class at VT later this year to learn all I can about the right and wrong way to do this. I welcome any and all input from all of you, and once it's finished, you are all welcome to come by and take a look.
:tinysmile_shy_t:

 

[Travis Porter]

Nice! Look forward to the continued progress updates and pics!

 

[jeff...]

Reggie, don't know if you seen this or not, but I thought it might be some useful information


http://owic.oregonstate.edu/askexpert.php --->

Q52: I'm planning to build a solar kiln and need more information about the safe rates of drying 1-inch lumber. I have information for some species but I need to have those rates for: pine, cedar, elm, ash, walnut, and cherry.

A52: There's an article by Gene Wengert and Dan Meyer about solar kilns that lists safe drying rates for beech, birch, hard maple, soft maple, red oak, white oak, and walnut.

In another publication, Gene Wengert lists the safe drying rate for 1-inch thick American elm as 10.4% per day. I can't find any information on ash.

For pine and cedar, given that softwoods typically are much easier to dry than hardwoods, it is hard to dry them too quickly in a solar kiln (as opposed to a steam kiln with temperatures near or above 212 deg F).

Of course, with any drying operation, you need to watch the quality of the boards (e.g., surface checking, cell collapse or warp), particularly in hot dry weather. If degrade is occurring, you can cover the solar collector with a tarp, open the doors to reduce heat, turn off the fans, or any combination of the above to cool and slow down the drying rate.

 

[Will Goodwin]

You mean it isn't, "Set it and forget it?"

Will

 

[jeff...]

Reggie, if it helps you any here's my stick figure for the solar kiln I was planning on building. I was quite serious about it at one time and even started collecting various pieces in order to build one.

Basically it's a two chamber kiln the upper part (attic if you will) is the heat chamber / solar collector. I had planned on lining it with flat black painted tin to capture and collect heat. Heat rises so there would be fans in the in the heat chamber to push the heated air down into the drying chamber below. The drying chamber is basically a double 2 x12 floor with double doors that swing open so it could be loaded with a fork lift. The drying chamber would always be in the dark unless the doors were open. To prevent the sun from cooking the lumber and besides ultraviolet rays from the sun are lumber color killers.

I never really got around to putting my thoughts on paper and finishing the design. But I was thinking of with a closed loop hot water boiler or heater system, pressure relief valve, small pump and hang some radiators in the heating chamber. For those days when supplemental heat will be needed because the weather won't cooperate. Also to maintain serialization (bug kill) temperatures. If I went with a boiler I think I could also add steam to stress relieve the dried lumber if I needed to. I think it would be fairly easy to control the heat with a supplemental heat source like hot water.

For the drying chamber I was thinking of installing a dehumidifier or two to maintain RH. Again I think RH could be controlled pretty easy if the dehumidification system were sized correctly.

I don't think my design is strictly solar it's more of a solar hybrid. Looking at kiln drying schedules what jumped out at me was consistency in maintaining Humidity / Temp and Time, like I mentioned before I don't know how you would do that in a solar only kiln without some other means of supplementing both Humidity and Heat.

I scrapped the idea after I figured out what I was designing was basically a kiln chamber and a DH system. For a few thousand I could buy a complete DH system ready to go from Nyle, build the chamber and be done with it.