Author Topic: Solar dry kiln construction (Read 8785 times)

Planman1954 · « **Reply #60 on:** September 16, 2011, 10:52:07 am »

OK...back to work on the kiln, after a long hot summer. Sorry for the long delay, but had some other things to attend to. The Kiln is now completed, and ready for a test run.

After attaching the top plastic panels and completing the wiring for the fans and dehumidifier plug, I ran some blocking between the front beam and rafters and made a framed box for the two fans to rest:

After the fans were set in place, I began installing the metal panels under the rafters. Remember, the metal pieces are centered between the top and bottom of the rafters, creating about an 8" space at the top and bottom for air to enter and exit. You can see the first few pieces in place behind the fan above. I used dry wall screws to hold them in place. Of course, the black painted side is facing up. Here's a photo showing the metal installed around the fans:

After reaching this point, my buddy Jimmy came by and took a look and suggested that I seal off the area between the fans to create a plenum, or a mini attic inside to direct the air flow. This shows a picture of the boards filled in between the fans with insulation above:

And then a photo with my camera held really high to show the insulation laid on top of the boards:

After these photos were taken, I filled in the end areas.

Planman1954 · « **Reply #61 on:** October 17, 2011, 03:17:21 am »

OK...finally time to do the doors. As I mentioned before, I decided to use multiple sections in the door area since my opening is about 16'-4" wide. I've seen hinges come loose on too many kilns with even smaller openings, so I decided to hinge a 3' section on each of the 2 ends, and then use removable sections in the center. I ended up with 5 sections, including the 2 doors. Anyway, each section (and door) is a simple rectangular 1x4 frame glued together with biscuit joints. It's pretty flimsy at first, but that doesn't matter. Next, I set the frames in place in the channels I made with the 1x4 trim around the whole opening at the top and bottom. The doors were hinged into the ends, and the center 3 frames were set in place. All 5 frames had about 1/2" between them...no perfect fit here....it isn't necessary. Then I began installing the siding over the frames. By setting them in place, this enabled me to keep the siding straight with a string:

Once the siding was installed, I removed the 3 center pieces and installed some 1" styrofoam insulation. Here's the before and after of that:

Next, a screwed my 3/8" x 8" boards to hold the insulation in place (being careful not to let the boards interfere with the fit on the channels:

Here's a photo of the completed kiln with the end doors open and the center three panels set in place:

This photo shows the doors open, and one center panel set aside:

And here is a photo of the rear canvas tarp cut to hang down. When a load of lumber is set inside the kiln, the canvas will be laid on top of the stack. This will direct the air flow back up to the rear top of the rafter plenum system:

Here's a photo of the completed Kiln, ready for use:

Mission accomplished!

Bill Gaiche · « **Reply #62 on:** October 18, 2011, 10:58:20 pm »

Looks good. Bet you are glad that job is done and ready to load her up. Tell us what are you going to dry first? bg

WDH · « **Reply #63 on:** October 19, 2011, 07:54:21 am »

Looks great! It sure is in a nice sunny spot.

metalspinner · « **Reply #64 on:** October 19, 2011, 08:02:19 am »

Thanks for all the detailed descriptions and pics.

I'm considering building a new kiln and seeing yours complete has inspired me to think about getting started.

Planman1954 · « **Reply #65 on:** October 19, 2011, 07:28:13 pm »

Well, my brother, a contractor, stopped by today and saw a large stack of beech that I cut into 1" material about 6 months back. He thought he'd ask his cabinet maker if he would like to buy it. If he's interested, I guess I'll load it into the kiln to get it down to 6% mc. Be nice if that works out.
I had planned on drying some cedar logs first in it though. I need to cut them to 1" stock and then stack them inside. Probably will be a few weeks before I have time to though. Right now I'm tearing down some old fencing here at my place. I'm trying to finish one thing at a time completely before moving on. Take care.

WDH · « **Reply #66 on:** October 19, 2011, 07:38:32 pm »

Quote from: Planman1954 on October 19, 2011, 07:28:13 pm

I'm trying to finish one thing at a time completely before moving on. Take care.

Don't set an unreachable bar for the rest of us

.

ljmathias · « **Reply #67 on:** October 20, 2011, 07:30:01 am »

Wow, beautiful kiln and what a neat idea- doing one thing at a time. I've never been able to do that. Yesterday, working on finishing up plumbing work for the dry wall to go up on the house I'm building, I started with some jackhammer work, laid it down to get a bucket for the chips, saw the door sill plates needed cutting in the closet, picked up a saws-all and did that, then went to get the bucket. Filled and emptied that, then grandson pointed out that we needed to finish framing up his "portal" window, so cut the pieces for that to make an octagon that will be the frame and nailed those in place. Then cleaned out some of the tools and left-overs to make room for the dry wall hangers... never did get back to the jack hammer so that's waiting for today...

Lj

Planman1954 · « **Reply #68 on:** November 06, 2011, 08:58:45 pm »

Hello fellers!
Been working outside this past weekend tearing down some old structures, and took some time today to stack a load of beech inside the kiln. I turned on the fans and the dehumidifier. It was great to see the air finally flowing around a stack of lumber. This particular load of beech has been air dried for about 6 months. The moisture content is about 10% right now. I hope to get it down to less than 6% so that I can sell the wood to a local cabinet maker.
I talked to pineywoods today, and he told me that this design doesn't fit any of the established drying criteria of typical dry kiln operations. He told me to let the fans and dehumidifier run continulously until the moisture content is what I want. During the day, the heat releases the moisture from the wood. During the night, the dehumidifier pulls moisture from the air at a higher rate than during the day. Oh, and btw, I bought my dehumidier at a flea market for 5 dollars. Seems like a good place to look for one, since I bought a second one for 10 dollars! The unit I'm using originally cost about two hundred bucks.
I'll try to take a photo during the week and post it showing the wood inside the kiln. I'll also keep ya'll posted on the time required to do the job. Take care. (UPDATE: The kiln seems to be doing a great job on the beech. I emptied about a half gallon of water the first day from the dehumidifier. When I open the door to check on things, it's almost like sticking my head in a warmer oven...I kid you not!)

Planman1954 · « **Reply #69 on:** November 30, 2011, 11:31:57 am »

Hey everybody:
The cabinet guy came by yesterday and said he would buy the load of beech. I showed him the mc was at 6% or below with a meter. It started at 10% when I loaded it, was 8% at the end of the first week, and now is at or below 6% here a few weeks later. I plan on putting the money towards a planer/molder and try to see if I can sell some crown mold and base. I've been looking at the Grizzly. Anyway, I am very happy with the kiln. It's perfect for a small potatos setup like mine!

WDH · « **Reply #70 on:** November 30, 2011, 08:16:44 pm »

Pineywoods should sell the plans! That is a really nice looking kiln. Post a pic of the beech lumber if you have one.

Bill Gaiche · « **Reply #71 on:** November 30, 2011, 09:11:34 pm »

Planman1954, I like small taters too. Glad you had sucess on your first load. Getting a new toy will be nice. bg

Planman1954 · « **Reply #72 on:** December 01, 2011, 09:25:29 am »

OK WDH. You asked, and now you shall receive:

First off, I remembered that I had taken a photo of the beech before I put it into the kiln. It had air dried for about 6 months:

Here's a photo of the end doors open, with the beech stacked inside:

And here's a closeup of my $5 dehumidier which worked like a champ:

The fellow is bringing his trailer today to pick it up. Next up...a load of red cedar for my brother. I'm cutting it all 3/4" thick (on my saw gauge) and then will surface one face to about 5/8". He's going to use it to line a closet in his home he's about to build. Take care.

pineywoods · « **Reply #73 on:** December 01, 2011, 09:42:32 am »

Re kiln plans. Nope, I'm not the least bit interested in sellin plans. Got too many projects now. HOWEVER, I'm gonna let the cat out of the bag... Planman would be the best source. He draws house plans for a living and has the talent and means to do a first class job. Like I've said before, there's not much unique about this kiln. It's really just a modified chicken coop....but it does work quite well...

Planman1954 · « **Reply #74 on:** December 01, 2011, 09:55:35 am »

Speakin' of plans...why do you need um? Just read the post from start to finish...cut some lumber, and start nailin' it together. That's what I did! But heck, ya'll have an advantage over me here by having some real-world pictures and a how-to guide to follow. It's more than I had. Seriously, that's why I documented the progression so that others could build one. Good luck.

zopi · « **Reply #75 on:** December 01, 2011, 08:04:30 pm »

I think you will find that lumber dried in a cycle such as yours will produce more resilient lumber that is more machinable...

I have a small building out back that is relatively tight...I think I will move it and put a set of panels on and convert it to a small kiln....

customdave · « **Reply #76 on:** December 01, 2011, 09:38:21 pm »

Neat job, well done, very informative , thanks for posting Planman... Play safe..

Dave

pineywoods · « **Reply #77 on:** December 01, 2011, 10:01:04 pm »

Quote from: zopi on December 01, 2011, 08:04:30 pm

I think you will find that lumber dried in a cycle such as yours will produce more resilient lumber that is more machinable...

I have found this to be correct. Hardwoods in particular are less brittle and easier to work when dried in a solar kiln. I am currently drying a batch of sycamore, supposedly one of the most difficult woods to dry.

WDH · « **Reply #78 on:** December 01, 2011, 10:05:18 pm »

Hopefully it won't warp its way out of the kiln before you are ready to unload it.

Planman1954 · « **Reply #79 on:** April 21, 2012, 12:09:38 pm »

I wanted to update a point about the clear plastic panels I used on the top of the kiln. Recently we had a hail storm, and it damaged the panels with about 40 holes. I thought about replacing the panels, and then brainstormed about how to repair them in place. I went to Home depot and bought one more plastic panel along with a bottle of PVC cement. I cut small pieces (about 4"x4") and placed glue on the existing panel around the hole, and then to one side of the new patch and set it in place. It worked perfectly! It took about 2 hours to cover all the holes...problem solved!

I just went out and took a closeup picture showing one of the patches near the corner:

News:

Author Topic: Solar dry kiln construction (Read 8785 times)