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wood drying kiln

Posted: Thu Apr 24, 2014 1:07 pm
by iloveairguns
So I'm making (at least trying to) make a wood drying kiln, which will be fire-operated and made of a 20 liter barrel, here's how it work: The barrel is placed in a horizontal position and the piece of wood is inside the barrel, under the barrel there is fire, which brings warm air inside the barrel, and from the other end of the barrel there will be (something) to blow air to the barrel so to circulate the warm air evenly, would this work? I'm gonna dry a log (split to three parts) and make a Moai statue of it. Is this even close to how a fire-operated wood drying kiln works? Aaaaand, ghetto style!

Re: wood drying kiln

Posted: Thu Apr 24, 2014 3:12 pm
by jrrdw
With low heat and given plenty of drying time, suspend the wood by hanging on a wire or lay it on a rack you should do well. You got a moister meter?

Side note: What did the Prospector expect to find?

Re: wood drying kiln

Posted: Fri Apr 25, 2014 1:57 am
by iloveairguns
I'm going to put the same type of metal legs on the inside of the barrel to keep the wood piece in center of the barrel, but is it absolutely necessary to circulate the air in the barrel? Also, does it matter which way up the wood is facing? ayway, here's a nice image for ya':

Re: wood drying kiln

Posted: Fri Apr 25, 2014 8:01 am
by iloveairguns
Bring Up My Post

Re: wood drying kiln

Posted: Fri Apr 25, 2014 8:17 am
by jackssmirkingrevenge
Hmmm... what stops the wood you are drying from spontaneously bursting into flames?

Re: wood drying kiln

Posted: Fri Apr 25, 2014 9:15 am
by iloveairguns
Well, As Jrrdw said, The drying should be done (should) on a low heat, and I don't really think that the air could get so hot as to light up the wood anyway, btw if it matters, the wood is pine, and what effect do you think it would have if i'd drill small holes to the bottom of the barrel? And, should I cut the bottom of the barrel off? Or would that disable the circulation of the warm air completely? And I know that applying sealant of some such will prevent cracking from the ends of the wood piece, what do you think, should I do it? And I may need to increase the length of the supporting feet. Oh, and sorry for the bump :roll:

Re: wood drying kiln

Posted: Fri Apr 25, 2014 10:18 am
by Fnord
I'm assuming you want the wood to remain more or less intact and free of defects?
If this is 'green' wood, it'll be losing so much moister over the first few days that you'll probably be better off putting it in a hot car.

After that you'll want a low heat over a long period of time. You can dry the very outermost bit of wood quite quickly but it has no effect on how fast water from the center soaks outward. Drying it out too fast will also cause cracks. If this is a problem you should remove the bark and coat any exposed growth rings with elmer's glue to lessen the chances.

Insulate the barrel, put a 100watt light bulb and a computer fan in it. Optionally get a humidity meter.
Shoot for a temp of about 100F to start with, then dial it up if you think it's taking too long.

Note that wood left in a normal environment will only dry out roughly 1" of depth per year, even with a kiln it'll still take a while. Cut it up as close to the final dimensions as you can, but leave 10-20% extra for shrinkage.


Source: Made bows for a while.

Re: wood drying kiln

Posted: Fri Apr 25, 2014 10:37 am
by jackssmirkingrevenge
Fnord wrote:Source: Made bows for a while.
Spudfiles does feel like a subreddit sometimes :D

Re: wood drying kiln

Posted: Fri Apr 25, 2014 12:05 pm
by iloveairguns
It's green wood and the wood piece's been drying outside(not in sunlight) for about three weeks now, the first thing I did after retrieving t he log was scraping off the bark

Re: wood drying kiln

Posted: Fri Apr 25, 2014 3:21 pm
by jrrdw
A steady low temp would be best so I can see a vent in the top to bleed off some heat if you need to. I really don't think you will need a fan because of the small size. Start off slow and low or it will crack/burn, you don't want that to happen. Experiment with it, I don't think any of us got it down to a exact science...

Re: wood drying kiln

Posted: Fri Apr 25, 2014 11:36 pm
by iloveairguns
Yeah, I'm gonna do it without the fan *first* because I've got three parts of the wood anyway, and I'm not going to make three statues anyway, maybe two, and thanks for the meticulous tip goes for Fnord. Btw, do you need a pic of the wood piece? I haven't measured the piece, but the height is about 25 cm at least, Here's some pics on how the piece fits in the barrel and of a small crack in the wood:

Re: wood drying kiln

Posted: Sat Apr 26, 2014 7:01 am
by iloveairguns
Sorry again, but I'll have to bump this :? propably unnecessary, since I *think* I have enough information? And Jrrdw, should I drill the small holes to the bottom of the barrel?

Re: wood drying kiln

Posted: Sat Apr 26, 2014 9:08 am
by Fnord
Yeah, seal the ends of it up and it should stop the crack from spreading.
Worst case scenario, if it does, just split it open and glue it back together.

You'll need to have some way for the moist air to get out of the barrel. A couple 1" holes will probably work.
A fan may seem kind of superfluous, but it will make a difference. Convection currents in a sealed container do not provide much air circulation at all.

Re: wood drying kiln

Posted: Thu May 01, 2014 8:30 am
by iloveairguns
Here's the kiln in operation:

Note: I've removed the legs of the kiln (the ones that keep the barrel midair, the ones inside the barrel are ALWAYS necessary)

Re: wood drying kiln

Posted: Sun May 04, 2014 6:28 am
by iloveairguns
Let's hope this bump won't get me banned...and let's hope it's the last one :roll: Ok I've used the kiln two times and it's worked well, I've been thinking about making the light bulb-powered kiln, Where should the fan be put? to the ends of the barrel or to the top? (in the horizontal position ofc) and does the bulb need to be so powerful as 100 watts? is 60 or 80 enough already? Oh, and should the fan blow inwards to the barrel of outwards? Oh, what's that wacky yellow wire in the fan? Can I just snap it off? I've looked in the web on what the heck it might be, but still not havin' a clear thought on what that is.