I've decided to build a solar kiln and it will be based off of the VT design. I have a large surplus of syp logs so I'll be sawing all of my own building materials. I plan on using board and batten on the interior/exterior walls instead of plywood. Are there any major negative consequences for using board/batten vs plywood? I don't mind using 3/4" plywood for the flooring, just didn't want to spend the extra $ for the 20 sheets of 3/8" plywood for the walls.
Yesterday afternoon, I cut forty six of the eighty two 8' and 10' 2x4's the plans call for...
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Hey Deese, welcome to the solar kiln club. The problem with board and batten on the inside is that you'd have a lot of seems to seal. You don't want warm moist air migrating into the insulation. Just my amateur observation. I'm sure someone more qualified will chime in.
I might just buy the plywood for the inside, but not sure yet. Still gotta finish sawing out the 2x4's and 2x8's and get some 14' lumber from another sawmillin' bud of mine (not a FF member) since I currently can only cut up to a 12' board.
We suggest that the interior have a plastic vapor barrier. With B&B, it is likely that there will be lots of holes in the plastic barrier. The interior covering is to protect the walls and vapor barrier so cheap plywood is ok. Usually particle boards, osb and waferboards do not have adhesive and construction that will last in a kiln. Use plywood with exterior adhesive, like CDx. A relatively smooth floor is really required, so the interior floor needs to be plywood.
Have you thought about closed cell (2 or 3 lb) spray foam and then covering with metal siding....closed cell provides a thermal and moisture barrier and no seams and the metal will protect the foam. More expensive but will retain the heat better and in a more uniform manner
Mr Gene, Thank You for your input. I will do as you say and use plywood for the interior walls and floor.
Woodshax--Yes sir, spray foam insulation did come to mind, but I doubt I will go that route...
DJ--very nice kiln you have sir!
Deese, I'll be watching with interest and cheering you on!r
Quote from: Darrel on January 20, 2017, 10:13:57 AM
Deere, I'll be watching with interest and cheering you on!
Thanks Darrel!
It seems that sawing more building materials will be put on hold this weekend, as it is going to rain for the next 2 days here. Ugh.
I sawed more 2x's for the kiln build yesterday along with other various pieces of lumber.
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The 12' trailer was loaded down. Only had to pull it a couple hundred yards.
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I cut some 3" thick slabs of 16" wide 12' long shortleaf pine. Very clear lumber. Going to let them air dry over the next several months, then dry them in the kiln. I figured they would come in handy for future woodworking projects, whatever they may be...They were HEAVY.
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One of my logs had a bad catface. I cut several 2" and 3" thick slabs from this particular log. With a little creativity, I think they could make some interesting tabletop/bench pieces. I would have to set the pitch in these for sure, as they are full of sap.
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I didn't work alone. I had my sawmill buddy with me.
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I've got access to a small walk-in cooler (appx 8'x8' inside) that isn't used during the Spring/Summer months. I'm hoping to experiment with it along with my solar kiln over the Spring/Summer.
I finally stacked the lumber I cut 9 days ago. I had left it flat stacked on a trailer in the shade. Very little sign of mold. I couldn't have gotten away with that during the summer months. Mainly 2x8's and 2x4's along with some 3"x16"x12' slabs.
Hoping to get started building the frame in a week or two.
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A nice looking stack on sticks :)
With my 15' track, the longest I can currently saw is 12' 2"
I want a longer kiln than that, and I'm not paying $200-$300+ for a bunch of 14'+ lumber.
Instead, I'll spend a tad more and get the 10' track extension.
All I need is a stamp and check will be in the mail tomorrow.
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I see some 22' SYP beams in the near future.
I'm glad my brother has forks on his tractor
Gonna be nice.
I'm excited.
Be warned that it is the start of a slippery slope (old saying).
No. Wait. You are already on that slippery slope :D.
Amen to that brother.
Looks like your going in the right direction. I use B&B on my exterior walls and used wafer board for the inside...It was laying around in the shop, so I got to use up some scraps.
I also cut all the wood siding and sticks for the frame.
Build the floor super strong, and have fun 8) and welcome aboard!
Dan
Look Out! 10' track extension with extra log clamp arrived just a few minutes ago.
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Already got it loaded and secured.
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I've got so much to do it's mind boggling. I need to set more posts and get it attached, but I only have so much spare time...I've got 30+ 12' long syp logs of my own still waiting, and a customer just called this morning and is dropping off 3 trailer loads of mixed pine and hardwood logs. Not sure how big the trailers are or how long he needs his lumber :o :-X I will contact him after work to get specifics. I am hoping he wants longer than 12' so that I will be forced to go ahead and get extension attached :D If not, I will probably proceed with what I have until things slow down a bit.
Got a call from another customer while I was typing the above post. He is searching for a service that I currently cannot provide, so he is being referred to another FF member that I know can suit his needs.
Thank you, Sir.
Have meant to build one for years but life's been getting in the way. So, will live vicariously in the meantime through your build....
Here are a few pics of a kiln in Woodstock, VT, at the Billings Farm Museum, site of the first Tree Farm. (Took the pics many years ago). Hope the design is helpful. All the best, Rob.
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We built a solar kiln with the plans from VT. For the collator we used plastic made for green houses. It last about 2 years and
then we have to replace it. Do you need the collator to be clear to let the sun shine in or could you just cover it to heat up the
inside. We have a lot of metal roofing that we could cover the kiln, planted black and put some on the under side of the rafters
planted black. Then use the fans to blow hot air down between then and then threw the stack of lumber? sure would save us
from having to replace the plastic every 2 years.
Sawwood
Sawwood, I don't know exactly what the numbers are, but somewhere I read what the difference was when just using black roofing for the heat collector. If my memory serves me correctly, if you did that, you would loose about 20% of your heating capacity. Maybe someone will reply with exact numbers. If I were you, I'd go to Home Depot and buy some of that corogated clear roofing, that's fiberglass reinforced. I've seen that stuff last 20+ years.
Update: I have decided against building the solar kiln...for now. Thanks to all who have reached out with advice.
The cover for a solar kiln was discussed in Sawmill & Woodlot magazine recently. There is no question that two layers are essential. Also, the further that the black absorber is away from the collector, the better.
Glass is a perfect cover, but often is too breakable...hail, rocks, etc. The stronger glass, like a patio door, is no longer as effective as a solar cover. Glass with a seal between the two layers (thermo-pane) will get cloudy quickly due to kiln heat. Glass that has a green edge is not so good. Glass is heavy, so the frame must be stronger.
Plastic film is ok if it is U-V stabilized. Sometimes the material made off-shore says it is stabilized, but it is not really that good. Plastic fIlm also gets brittle and then will tear, especially due to flexing from wind and fans. Five year maximum life, but often much shorter.
Polycarbonate (single or double) is strong and durable, but somewhat expensive. It is Very easy to install. The two layer stuff seems to be close to perfect.
Corrugated fiberglass will last for 20 plus years and is low cost and durable. It is not 100% clear, but other benefits make this covering very practical.
An FYI for anyone looking at corrugated poly-carbonate panels. HD and Lowes carry panels that appear to be identical, and (as of last fall), they were selling at the exact same price. The panels HD had were actually 40% thinner.....
Good info Doc. See you Saturday.
Quote from: GeneWengert-WoodDoc on May 13, 2017, 08:38:02 AM
The cover for a solar kiln was discussed in Sawmill & Woodlot magazine recently. There is no question that two layers are essential. Also, the further that the black absorber is away from the collector, the better.
Glass is a perfect cover, but often is too breakable...hail, rocks, etc. The stronger glass, like a patio door, is no longer as effective as a solar cover. Glass with a seal between the two layers (thermo-pane) will get cloudy quickly due to kiln heat. Glass that has a green edge is not so good. Glass is heavy, so the frame must be stronger.
Plastic film is ok if it is U-V stabilized. Sometimes the material made off-shore says it is stabilized, but it is not really that good. Plastic fIlm also gets brittle and then will tear, especially due to flexing from wind and fans. Five year maximum life, but often much shorter.
Polycarbonate (single or double) is strong and durable, but somewhat expensive. It is Very easy to install. The two layer stuff seems to be close to perfect.
Corrugated fiberglass will last for 20 plus years and is low cost and durable. It is not 100% clear, but other benefits make this covering very practical.
Might have something of value to add (doubtful but here goes).
In the greenhouse hobby world a recent trend has been to use bubble wrap meant for pool covering. It is UV stabilized, it has a great R factor compared to the other materials, cost per sq ft is very very low. Now this is in the greenhouse world where they need to cover large areas. However, it is holding up well, early adopters from a few years ago report no problems and it is dead simple to install. Anyhow, something from another industry. Hope it worthy of consideration
Nativewolf, I had not heard of using the pool cover bubble wrap, but there is a product called solawrap which is made for the greenhouse industry that sounds very similar. Supposed to be very durable with very good longevity. Greenhouses in the UK have been covered with it for over 20 years with little to no degradation. I've not priced it here in AK, although we do have a dealer for it in the state, I've thought it would make a good solar cover for a kiln.
Interesting. The thing with pool covers is that there are maybe a million pools, many have covers. That means that industry has scale and prices are lower.
Just an fyi for you since R values might matter more in AK, folks are double layering it, then putting in blower fans to push an air blower between the layers (this is for the greenhouse world). With the air layer R value goes up dramatically. Pretty simple and very cost effective in greenhouses, maybe in your neck of the woods too?