Making charcoal in a 15 gal keg

[CaribouForge]

Hello eveyone,

I want to make some charcoal using a 15 gal keg. My question isnt so much on how to do it but on how long I can expect it to take for planning purposes. Also, is it better to start the fire in the keg then cap it once it going or to cap it at the start and build the fire around it?

Thank you

[Hefty]

I can't comment in terms of time for that volume, but I build a fire under and around my 20 litre (5 gal) bucket in the evening and get it going well, let the process happen and then open it the next morning. My understanding is that if you don't wait long enough and there's still any significant heat inside, when you open it up it can potentially start to smoulder and burn through all your brand-new charcoal.

I also have the bucket raised off the ground slightly with a chimney that directs the heat of the fire underneath, through the middle of the charcoal bucket itself. I fluked a self-sustaining wood gas vent where the bottom hole for the chimney doesn't seal properly so the wood gas vents down into the fire underneath and helps the process.

Hope that's helpful.

Cheers,

Jono.

[Frosty]

There are just too many variables to the process to be able to answer a question with so few specifics. For an "extreme" example different time, charcoaling pencil dia. bone dry spruce sticks takes a fraction of the time as the same volume of 1" dia. green oak.

Most of us who have successfully made batches of charcoal watch it and when it's done smoking block the draft and let it rest till cool.

There are some really slick semi-direct charcoal kilns using a version of a rocket stove as an internal heat source. Using the alcohols and ketones pyrolized from the wood as fuel to support the process is what makes it a Semi-direct process. If you shovel coals out of a camp fire and extinguish them that is a Direct- process. 

A sealed container with externally fueled heat source, say for making wood alcohol it's called Indirect.

Experience is the only way a person can "plan" duration of the process unless you have some pretty sophisticated sensors and instrumentation. 

Frosty The Lucky.

[BillyBones]

From what i have seen and experienced in making charcoal is that it is an all day thing. Start in the morning and be done late afternoon or evening. Like BBQing a brisket. Take a Saturday and start your charcoal, mow the grass, pull the weeds out of the flower beds, maybe some small repairs around the house, sit in the shade and have a beer with a buddy, while every once in a while checking on how the charcoal is coming along. Your method will depend on how you check it. I am familiar with mostly external heating and you just wait till the flame goes out from the off gassing. 

Like Frosty said, there is no way to really answer that, like BBQing a brisket. You just cook it low and slow till it is done. 

[lary]

Half to most of a day in my experience. If you're taking a 15 gal. barrel, packing it full of short pieces of lumber, standing it upside down in a 55 gallon burn barrel, then cram as much dry wood maybe up to 1 and a half inches in diameter in-between the walls of both barrels and pilled on top of the small barrel. 

[Nobody Special]

Always liked the direct method - start the fire in a raised 55-gallon drum with a few holes knocked in the bottom with a pickaxe, fill 'er up, prop the lid open a little with a "rock or something". Let it burn down a bit and add more wood.

When the smoke changed from water vapor to wood gas, drop the lid and the drum so it's airtight-ish. Let it sit overnight, open it up and if it doesn't flare up, break up your charcoal billets. Maybe 40 percent charcoal out of what you started with, but it's as easy as it gets and that plus a beer or cider is a fine way to kill an afternoon.

Don't drink when busting up billets with a knife. It only ends in tears. Also blood and ruined t-shirts...or um, so I've heard.

[Shainarue]

I do it somewhat like Nobody outlined. Make sure to cover the air holes when you cap it off though. 

My 55gal has holes all around the base, with one hole large enough for a pipe which I attach to my hand pump to blow air in when the fire needs a little help to get going. 

Add some wood - I usually go about 3 layers of crisscrossing - and burn till the top pieces are charred good and crispy, then add more. When you get to the point you can't add any more, wait for the crispy char then wait a little more. Then I don some welding gloves and put the lid on (I have a clamping lid but a big stone works just as well to hold it down). I learned my lesson the hard way about trying to get the lid on tight without gloves. Once the lid is on tight, the fire will start pushing out of the air holes. I cover those up with sand. Basically I just shovel a small mound all around the perimeter of the barrel. 

All that usually takes me about 6 hours and I usually forge or do yard work while it's going since it doesn't require constant babysitting but does require not being left unattended. Once it's capped, I feel okay about going inside but I'll check out the window often. I'd never leave the house until the barrel was cool to the touch. 

One time, I wanted to leave so I tried to empty it on the same day - maybe 4 hours later - and it reignited where I dumped it. I doused it in water until some of it was floating. Then I shoveled all that wet charcoal back into the barrel and locked the lid before I left. Made for more work since I had to spread it out to dry the next day. I suppose you could try just running a hose into your keg when you need to leave (I'm assuming this is why you need a timeframe). But make sure to soak it good if you're going to do that. And then dry it out before you store it.

But mine is 55gal using 3-4" logs (hardwood, usually oak, maple, or walnut) which fills a 30gal barrel with the resulting charcoal. I don't know how the timeline would change for a 15gal with whatever size/type wood you're using (likely smaller).