Adventures in charcoal

[Nobody Special]

So, I've been trying for the longest time to make charcoal for a bloom.  I figure I need about 150 lbs or so to do around 70 lbs of ore. Been trying a lot of different methods, indirect, semi-direct, and of course, the classic - direct.

 

All attempts have been in a 55 gal drum.

 

First go was indirect. Loaded the drum, carved a hole top and bottom to run a 6 inch stovepipe through, let it stick out the bottom, and put the whole thing over a shallow pit. Lit a fire in the pit and fed fuel down the stovepipe. Had holes in the stovepipe to vent gas. Mixed results. When it worked well, around 30-40 percent charcoal. Biggest mistake, as in all of these was having my chunks of wood too big. Lots of unburnt remnants.

 

Got tired of it and tried putting a 30 gal can inside of same drum, upside down, with the outer drum. Sat on the ground, closing bottom hole.  Long stovepipe for a chimney out the top, holes in the side for ventilation. Rarely worked, not enough space between the inner retort and the outer drum. When it did, maybe 25-30 percent, Only really charred where the wood sat on top of the retort.

 

Latest attempts, direct method straight out of bushcraft magazine on youtube, and occaisonal semi-direct. New 55 gal drum with 7 - 2 inch holes in the bottom, place on blocks, start a fire, load with wood, prop open, then take off of blocks and seal after about an hour when smoke changes color. Varying from around 20-40 percent yield. The shorter the burn, the more yield so far. The internet reccomendation was around 3 hrs. Found out I don't end up with anything if I don't seal it after about 45 minutes to an hour.

 

Also, retried indirect method, and elevated the the outer drum so the bottom hole was partially exposed. Worked much better, seemed to get more oxygen. Haven't opened it yet to see results, but much better burning in outer drum.

 

Conclusions? Sealed retort is harder to do, but yields much better charcoal. Smells good, denser, lights easier, better texture, and less fines. Direct method more consistent, but lower yield and less density.  Pine is lousy by itself, not dense enough, but if you mix it with hard woods, seems to get better results out of both woods.

 

About 100 lbs right now, and maybe 20, 30 gallons to check on in morning. Advice? Comments?

[Frosty]

Your first example if indirect isn't nor is your semi direct. Both are direct with no control of the air. 6" stove pip has no place in any method.

 

Get a 55gl drum with a clamp lid and a bung hole. Screw in a 2" nipple screw on a 90* ebow and standing the drum on a couple bricks run another nipple from the elbow to the edge of the drum. close all the other free space around the drum with whatever so long as air can't enter. fill the space under the drum with small wood, nothing over say 2# be it whatever from old lumber to brush wood. Light it up and keep it fed so it roar. Shortly you'll begin to see smoke coming from the pipe when it starts burning stop putting wood under the drum and let the gasses being driven off by pyrolization fuel the retort.

 

Keep a watch on it ad when the fire starts to die stuff something in the pipe so NO AIR can get in but not so tight it crushes the drum as it cools. Wait till it's cool to the touch and open it the NEXT morning. Empty your charcoal but store it OUTSIDE in a metal container. WHY? Embers can smoulder for several days till they get a decent amount of air and THEN light back up.

 

Semi direct is easier. Punch 2-3 2" holes in the bottom of a drum with a snap ring lid, NOT the side at or near the bottom, the BOTTOM. Stand the drum up off the ground a couple inches and make sure the ground under it is SAND. Now, start a fire in the drum and then fill it with uniform sized smallish wood. Once it's rolling good and strong put the lid on it and snap the ring. Then take the supports out from under it and seal the bottom off with the sand so NO air gets in.

 

Wait till it's cold and open it the next day.

 

Putting a 6" air intake and a 6" stack on a barrel makes a wood stove, not a charcoal retort.

 

Direct method is simply shoveling coals out of a fire and quenching them. OR using an air blast to charge the coals in a fire to welding heat.

 

Frosty The Lucky.

[Marksnagel]

I decided to give making charcoal a try last year and now I make more charcoal than I can use. I use it primarily at the forge even though I still have coal. I also use it in my charcoal grill.

 

I can't figure out how to get the pictures from point A to point B, so go to my facebook link below and look through my pics. Wander through my page and with the pictures I give a fairly good description of how I made it and how the operation goes.

 

My charcoal retort works great and each burning results in 90 - 100% burn. The best wood I have found for the forge is old oak pallets. 

 

https://www.facebook.com/pages/Revealed-By-Fire-Blacksmithing/228941297128590?id=228941297128590&sk=photos_stream

[Charles R. Stevens]

Try looking at the black powder forums, some of them have very fancy retorts, one used a double barel stove kit, and mounted a 30g clamp top inside the top drum as a retort. Those guys are after very high quality charcoal.
I found reams of stuff by googling charcoal retort, and checking out the images.
Can't beat Frosty for simple, effective and quality. Rarely do you need to trim the hair off his advice to work for that mater.

[Nobody Special]

Frosty, your semi-direct is almost exactly what I've gone too. More holes on bottom, and letting burn about 50 minutes before sealing. Anything before that, I end up with lots of uncharred bits, but like I said, my pieces are probably too big. Seems to yield around 30-40 percent. Worst case, burned too long, about 25 percent.

[Charles R. Stevens]

In a indirect fired retort you burn about 1/3 of the wood in fuel under the barrel.

[Nobody Special]

My first tries were indirect.

 

Yes it used a stovepipe chimney, but it went through the middle of the barrel top to bottom, and the fire was underneath the barrel, so none of the wood in the barrel was on fire.

 

The pipe had a few, very small vent holes near the bottom to vent wood gas back into the fire, but not enough oxygen was getting in for it to do more than smoulder, especially after it heated up enough for the pressure from wood gas to push everything out.

 

When it worked, it worked very well, but I couldn't get it to run consistently. So I tried the retort inside a larger barrel, and finally switched to the semi-direct.

[DanielC]

Not to toot my own horn, but it worked decently enough for me at the time: http://www.iforgeiron.com/topic/30286-making-lump-charcoal/