Finally got to start my solar kiln

[btulloh]

I'm seriously thinking of building a couple more,

I wish I'd built the second one first.  After building the first one, I know what I'd do differently.

[PA_Walnut]

Remember, I don't use it for any wood that is prone to sticker stain, as its the wrong tool for the job.

All of my "good" stuff gets air-o-flo stickers...even walnut. I've made a SIGNIFICANT investment in them in order to avoid staining/shadowing. They work great!

[thecfarm]

btulloh, :D   One of my sayings,I have to do things twice,so I know how to do it the second time.

[Coffee_Creek]

I built an airplane a few years ago, sure am glad it worked the first time  :D

[Coffee_Creek]

 

 Made a little more progress the last coe of days installing insulation bats and skinning the walls with plywood, painted the plywood and 2x4's to frame the plenum, I hope to build the plenum and install the fans and wiring tomorrow, ordered timers they should be here tomorrow, I plan to run four fans during the day and two dehumidifiers at night....



 

 

 

 

[btulloh]

Looking good.  Almost ready for taxi tests.

[YellowHammer]

Running dehumidiers in a solar kiln can sometimes become problematic.  It negates the ability of a solar kiln to fully equalize wood at night, and also means the kiln is basically running at 100% duty cycle, which with some wood species may exceed the maximum safe drying rate.  

I sometimes run dehumidifiers, especially in the winter, but for summertime, and with thicker more drying defect prone wood, I actually prefer to dial my solar kiln back to more conservative levels.

 

[farmfromkansas]

Would it make more sense to just run the dehumidifier during the day?

[Coffee_Creek]

That's why I'm posting my intentions so that you guy's that know what you're doing can help me keep from doing this totally wrong and I appreciate your imput. I'm as new at this as I can be never have dried lumber before.
I have a barn full of hardwood such as beech, red oak, white oak, quarter sawn sycamore, syp and poplar that has been air drying for two years. I plan to make T&G flooring from the hardwood and base board molding, crown molding and such out of the poplar.  I also plan to make a lot of outside door and window molding out of the air dried lumber.
I need to get about three thousand board feet of hardwood down to around 7 % MC as soon as I can, we're in the process of building a new house and I'll be making all the T&G flooring.
I had read where a guy used dehumidifiers at night to help the drying process.
Any words if wisdom from you guy's would be very much appreciated.......

[WDH]

If your wood has been air drying for 2 years, you can't hurt it with running the dehumidifiers.  Green wood would be a different story.  Fully air dried wood will do fine. 

[GeneWengert-WoodDoc]

As YellowHammer points out, there are two different circumstances when using dehumidifiers (DH) in combination with solar kilns- -green lumber and air dried lumber.

With green lumber, the high humidity that a solar kiln achieves every night serves to relieve any drying stresses (also called casehardening).  Removing this high humidity with a DH will likely result in dry lumber with drying stresses and may also dry the lumber too fast if the solar kiln is working well in warm, sunny weather.

With air dried, the stresses were relieved every evening with high RH that naturally occurs.  So, DH drying at the lower MCs can help speed drying safely in a solar kiln, although the cost to remove moisture from lumber will be quite high.  However, see the next paragraph...

Appreciate that a solar kiln is not a good thermal device in which to add heat in the non-solar hours.  That is because the collector is thermally not too good.  To fix this, you could cover the collector with a blanket at night.  A DH equipment requires a minimum temperature to work well—70 F or warmer.  In fact, with air dried lumber, it is likely more efficient and more economically beneficial to build a well insulated kiln without solar input and use 100% DH, especially in cooler or cold winter months.  Further, a DH at 120 F or even 130 F 24/7 will dry much faster than a solar kiln.

Another alternative would be to build an insulated kiln and then build a separate solar collector that can be "removed" or isolated from the kiln when the sun is not shinning.  Run DH most of the time and use solar supplemental heat.  Overall, quite expensive.

[Coffee_Creek]

Looks like I lucked out, I have two nice new dehumidifiers for my gun room  8)

[Ianab]

Because the wood is well air dried it's pretty hard to mess up. 

You could use your DH to complete the drying, simply by shutting it in a room with the DH and a couple of fans. If you can keep the humidity in the room down to ~40% RH, the wood will dry to around 8%, probably in a matter of weeks. As long as the temperature is over the minimum for the DH to operate, it's going to dry. Being a bit warmer will speed things up. But because the wood is already "dry", you don't need the more precise control or the "reconditioning cycle" that regular or solar kilns provide. 

The wood is probably around 12% now in the barn, which I could use "As is" in my climate. But I understand you want yours a bit drier to account for the dry indoor winter conditions. 

But it really just needs to be acclimated now.

[GeneWengert-WoodDoc]

Heating the wood through and through to 133 F will sterilize it for,insects.

[Coffee_Creek]

Still at it slowly but surly, built plenum and install fans.......

 

 

 

 

 

     

[GeneWengert-WoodDoc]

I am impressed with the quality you have.  Nice job

[Crusarius]

That is looking great. I am definitely saving this thread when it comes time for mine. 

[YellowHammer]

Nice

[btulloh]

Gettin' close to the finish line.  Nice.  Those fans look good.  Gable fans?

[Crusarius]

I keep thinking when it is time to do my kiln I want to use ford taurus fans. They are 2 speed, 12 volt, and can resist road salt in a car. I would think they would hold up pretty well in the kiln. 

Plus by going 12 volt powering them has a few more options.

[Coffee_Creek]

The fans are cheap Lasko floor fans, I removed the tubular leg and the front grill and used wood screws with flat washers to mount to the plywood.........

[Lawg Dawg]

This is looking great!  Like alot of folks on here, I've been following but not posting, I've been needing one of these for 8 years now.  I saw alot of pine boards, and would like to have one to get the boards under 20 percent quickly, so they don't mold so fast.

[Coffee_Creek]

 

 

 

 

 Thanks Lawg Dawg, I put this build off for 2 years, sure wish I had built it then, oh well......

Had a rain delay but still managed to finish one door and get it hung.....

Thank God for hydrulics and pneumatics......

this is one heavy door, just standard framing, 2x4's on 16" centers, add two extra on each end for hinges and door latches, I nailed a few 2x4's inside the kiln to catch the door as I slid it in place, worked like a charm.....
The two short 2x4's that you see nailed to the outside were to hold it while I moved the skid steer and installed the hinges.

[Coffee_Creek]

Not many pic's but I finished the second door, installed hinges, catches and latches.....


 

 

[samandothers]

Those must be hefty hinges! Where did you find them?