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Dry Kiln Construction Project

Started by logboy, September 02, 2012, 12:29:30 PM

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logboy

I know how you guys like project photos and such so I thought I'd start a thread on my kiln construction.  The project has been sitting idle for a few months as I've had plenty of more pressing issues to contend with.   Yesterday morning after I sold a pickup load of white pine lumber to a customer,  I suddenly felt the drive to frame it up and make some progress.  I think mostly I will be drying slabs for tabletops, benches, furniture, etc. Inside dimensions are 20 x 9 x 8.  In hindsight I wish I would've gone a little taller, but I didn't have any stacks of 9 foot 2 x 6 around and I really didn't feel like buying any. Besides, I really do not feel like stacking/ stickering lumber beyond head height anyway.  I think most of what I dry will be large tabletop slabs.   I'm still not dead set on how I will do the doors so I welcome any and all input.  I need to saw up the wood for the rafter next. I have thousands of bdft of pine laying around begging to be sawed, so it shouldnt be a challenge for my Lucas to zip through in a hurry.


Lifting the header in place. I used a couple 12" LVLs nailed together every 16" and glued with PL400 subfloor adhesive.



Header in place. Its high enough to get the forklift or Bobcat  in and out. I'm still debating raising it a few inches and using hanger brackets for the joists. The fans hang down 20" though so its still higher than them.




Kiln in the background with the Ebac LD3000 in the foreground. I've been sitting on it for 3 years. I figure its time to put it to work.




I like Lucas Mills and big wood.  www.logboy.com

logboy

I'm glad that I reread the manual before I got too carried away with the construction.   I was just going off Ebac's recommended kiln size for 16' long wood.  For the volume that is ideal for the dehumidifier,  they want a 6 foot wide stack. 6 foot? Who makes a 6 foot wide stack?  That would mean I need to cut a whole bunch of 6 foot wide stickers specifically used for the kiln and nowhere else.   That would also mean breaking down every one of my 4' wide stacks and re-stacking them for the kiln instead of just putting them inside with the forklift after air drying. So, going off of their recommended size for an 8 foot wide stack (two 4')  I needed to add another 2 1/2' to the width for it to be ideal in drying.  I was 1-1/2' short.   

So yesterday I spent an hour or so yanking the header back down, using the reciprocating saw to cut the nails,  framing another foot half on the front of the kiln, cutting back the top plate to properly lap the new joint, and putting everything back together.  Good thing I used to frame houses for living.
I like Lucas Mills and big wood.  www.logboy.com

Larry

I've been known to read instructions last...always costs in the long run.

I have a Nyle 200 that's been sitting waiting on me for about the same amount of time. :-\  I got my pad poured. :-[ 
Larry, making useful and beautiful things out of the most environmental friendly material on the planet.

We need to insure our customers understand the importance of our craft.

Compensation

Looks good! If i had that set up i would do 4 panels for the doors. Centers slide in front of the left and right doors and then hinge them to swing out. That would toss a wow factor like none other and save some swing space in the process.
D4D caterpillar, lt10 Woodmizer, 8x12 solar kiln, enough Stihl's to make my garages smell like their factory :) Ohh and built Ford tough baby!

Leigh Family Farm

Nice project. Manuals aren't just for leveling the dining room table  :D Good thing is that you didn't put the siding on and then realize you were 18" short. Keep the updates coming!
There are no problems; only solutions we haven't found yet.

logboy

I tried to get a bit more done before I head off to Ohio on Monday. After finishing up a couple lumber orders, I spent a day sawing the rafters/floor joists. It wasnt the quality of wood I was hoping for, but for my purposes should work OK. I burned up all the clear WP filling orders.  I ended up one rafter short. I'll have to saw it in a couple weeks.









I have a lot of slabs waiting to go in there.
I like Lucas Mills and big wood.  www.logboy.com

Okrafarmer

Quote from: logboy on September 03, 2012, 02:08:41 PM
I'm glad that I reread the manual before I got too carried away with the construction.   I was just going off Ebac's recommended kiln size for 16' long wood.

That's what you get for reading the directions in the first place!  ;D
He that dwelleth in the secret place of the most High shall abide under the shadow of the Almighty. Psalm 91:1

Operating a 2020 Woodmizer LT35 hydraulic for Upcountry Sawmill, Dacusville, SC

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Tree Feller

Quote from: Okrafarmer on September 29, 2012, 01:42:02 AM
Quote from: logboy on September 03, 2012, 02:08:41 PM
I'm glad that I reread the manual before I got too carried away with the construction.   I was just going off Ebac's recommended kiln size for 16' long wood.

That's what you get for reading the directions in the first place!  ;D

Yep. Ignorance is bliss.   :D
Cody

Logmaster LM-1 Sawmill
Kioti CK 30 w/ FEL
Stihl MS-290 Chainsaw
48" Logrite Cant Hook
Well equipped, serious, woodworking shop

logboy

My kiln project that has been sitting idle for a couple years has just been thrust to the front burner.  I just picked up a sizable customer who lives in Arizona and wants a steady supply of slabs for his contracting business.  Slab business has been picking up anyway so this is something I have needed to get done.  The kiln will primarily be used to dry slabs 2.5-3" thick.

I will try to only run air dried slabs through, but the problem will arise in the winter when I just can't do that due to the fact it's colder than a witch's hiney here in northern Wisconsin and nothing dries until spring.  He wants them kiln dried and then planed since they do not have the capability of planing slabs 4- 5 feet wide like I do.

Because these are going from Wisconsin to Arizona they will need to be quite dry before I plane them.  Can anyone recommend a drying schedule or advice for hardwood slabs? Lets say starting MC of 20%, final 6%.  How fast can I dry them without a ton of stress coming out when I plane them?  The defects are not as critical as lumber.  As customers keep telling me cracks and other little defects simply add to the flavor of the rustic look. One person's defect is another person's rustic I guess.

I am going to put at least one layer of closed cell spray foam in the walls and ceiling followed by fiberglass.  I am dreading what my energy bill will be when it's -30 outside.

The dehumidifier is an Ebac LD3000. A local guy put in auxiliary heat in his kiln because the internal heater is rather weak. Can I get away with a floor register on the back with an external thermostat?

How will the water drain in the winter when its extremely cold out? Will I constantly have issues with the drain hose freezing up?

The dehumidifier came with two 16" fans that run at 1725 RPM. I dont see a CFM on them anywhere so I dont know if it is enough or overkill.

Do I need to integrate a vent into the kiln? I do have a greenhouse fan with its own thermostat that I could add if necessary.

Comments, questions, recommendations much appreciated.


I like Lucas Mills and big wood.  www.logboy.com

Den Socling

I don't want to throw cold water on your idea but I don't think it can work. 12/4 hardwood slabs would require years of air drying to get the core to 20%. And I don't think a DH kiln could ever get them to 6%.

logboy

Unless you start selling a vacuum kiln that doesnt cost as much as my house and can take a 72" slab its going to have to work.
I like Lucas Mills and big wood.  www.logboy.com

Den Socling

We have kilns that take 80" slabs and cost only as much as your Mercedes.  :D Seriously, have you researched the time involved in air drying a 3" slab. It is years. And then, besides all of the degrade, you have slabs with moisture contents all over the place.

logboy

Well since I'm apparently the first person in the history of mankind to try and kiln dry 12/4 slabs I'll just have to figure it as I go, right?
I like Lucas Mills and big wood.  www.logboy.com

Den Socling

I'm contacted almost daily by people who want to dry slabs. It's currently a hot market but Google slabs. There are a lot of people trying to do it.

logboy

I have clients (furniture makers, mostly) who do it all the time with slabs I saw from their logs. They air dry a few months (not years) then put them in the kiln for 4-6 weeks. The final products are high end rustic furniture so degrade in the end product is not an option. The last few years I have simply air dried everything with good results. In my experience most of my degrade comes early on in the drying process, not toward the end or after surfacing. If it can be kept flat and relatively degrade free in the first 3 months after cutting then I end up with a good slab in the end. I have yet to get an angry phone call from someone with a slab that cracked in half or turned into a banana after they took it home. I know enough people doing it in a standard DH kiln to know it can be done, so I will follow their lead.
I like Lucas Mills and big wood.  www.logboy.com

Den Socling

I dry a lot of slabs. I get them under 9% but a higher MC would be OK for the type of furniture construction used. Air died would work but wouldn't be sterile. If you seriously need 6% for AZ, you have a problem.

Seaman

Logboy,
I agree that the first couple months of drying slabs is critical. I think you will be fine, but I think 6% is going to be a hard target. Around here 15% or so is OK for glueup. If you fasten down a one piece slab in a way that allows movement, a lot more can be tolerated. I don't know the exact number, and do not think there is one.
I have started using the steel tape with holes in it ( pipe hanger type) across end splits as I cut. Then I band the whole stack to keep the top one from twisting. Wooden shims under the bands later keep them tight through the whole drying process. So far this is working well, and will hopefully make the planeing unnecessary at the end. Band them again before shipping to Az, and I think you will be fine.
Frank
Lucas dedicated slabber
Woodmizer LT40HD
John Deere 5310 W/ FEL
Semper Fi

Den Socling

Seaman,
Name a couple species and tell us how long it takes to get 3" slabs down to 15%.
Den

Seaman

Den,
I buy no means claim to be an expert at drying, and have little experience so far.
I took poplar ( air dried about 4 weeks) and maple ( air dried about six months) to a local lumber co that has been in the kiln business for 61 years. They dried both down to 15% in 12 weeks or so. The only damage was in the top slabs which I did not weight down, that is why I band now.
I did not weigh test pieces and all that, but have sold to table makers and glued some myself, and all is well so far. Been about a year so far.
I just think ( and may be proven wrong) that like the Piney Woods Kiln, It doesn't have to be as exact as some suggest. I have seen where fastening techniques  allow slabs to be used a lot wetter than if a glue-up is involved.
I may end up wearing a Dunce Hat here, or maybe not.
Frank
Lucas dedicated slabber
Woodmizer LT40HD
John Deere 5310 W/ FEL
Semper Fi

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