Transition Culture

An Evolving Exploration into the Head, Heart and Hands of Energy Descent

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7 Mar 2006

Top Five Things to Do With Oil Barrels When There’s No More Oil To Fill Them – #1. Make Charcoal.

cartoonOver this week I will be taking a look at five things we could do with oil barrels when we are no longer able to put oil in them. The idea came from the cover of Peter Tertzakian’s new book A Thousand Barrels a Second : The Coming Oil Break Point and the Challenges Facing an Energy Dependent World (you can hear an interview with the author here) which I just started reading, which has a great picture which shows a huge collection of such barrels. Struck me that we’re going to have an awful lot of them left lying about the place, and perhaps they might become rather useful things. To that end, I would like to offer you **TransitionCulture**’s Top Five Things to Do With Oil Barrels When There’s No More Oil To Fill Them, some you may already be doing, some may never have occured to you, but all of which are practical and useful and which may well become a central part of your life in an energy descent culture.

**No. 1. Make Charcoal in Them…**

ccrPeople have made charcoal for thousands of years prior to the ‘Petroleum Interval’ and will continue to do so long after its impending demise. John Evelyn in 1786 wrote that charcoal was the major product for many coppice woods. Charcoal from oak was used in iron works, alder and lime used to make gunpowder, and all the rest used to make *small coles* that warmed the grates of London (history’s first attempt at a smokeless fuel). Converting wood to charcoal, despite the fact that the process results in the wood losing 80% of its weight, increases its financial value 5 times and its calorific energy content doubles. It is also very useful stuff. I emailed fellow permaculturist Graham Strouts, who has spent more time in woods doing ‘woodsy’ things than I have, to ask for his thoughts on the usefulness of charcoal, here is part of his very informative reply.

>Charcoal will be an essential part of a post-fossil-fuel society and the skills required to make it should be on every peakniks list of “Things to Learn”. The main use will be in fuel for a forge. Given the basic equipment of a forge and anvil and charcoal-making facilities (an oil drum and a bow-saw) it is easy to make charcoal on a small scale, which can be used
to forge metal. Charcoal can actually reach welding heat, which is 400-500 degrees hotter than you need normally in a forge.
Being able to make our own hand-tools from metal will be an essential part of any future community.

>At the Ecotopia Festival in East Clare a few years ago, I made fire on a “bow-drill” by friction, using birch bark and dried hemp as tinder; this was then carried to the forge and was used to light the charcoal which had been made the night before for the forge.Wood-working tools such as draw-knives and chisels for the pole-lathe were made by the blacksmith, which could then be used to make everything else we need from wood.

>So there was a tremendous sense of continuity and “closing the loop” in following this process through. Whenever I’ve discussed this in classes I can see it makes a big impression as people begin to get a sense of how a really low-impact economy could work: using very simple technology, with charcoal we can make our own tools for woodworking. With these tools, we can make everything else. Since it can be made from forewood from coppice, it represents an sustainable fuel source.

>Charcoal can also be used for making wood-gasifiers which can power vehicles. This process was used extensively during WW2. The Kerry Alternative Technology people have made one. I recently got an email from Sue Dennet saying that David Holmgren had recently succeeded in making a wood-gasifier for vehicle use himself. This might be an even more significant use for charcoal.

On a small scale it is made in a number of ways, but the smallest scale people make it on is in old oil barrels. Making charcoal is often the key to the management of small woodlands being viable, and recent years have seen great strides in woodsmen forming co-operatives and branding their charcoal as being from sustainable local woodlands. It is best made with 20 year old coppice timber, and from rubbish wood that is no good for anything else. Charcoal finings (the fine dust too small for burning) is great to put in the garden as slugs hate it. Ben Law in Sussex uses it on the paths in his garden and raves about its slug repellent properties.

CCHere is how to make it, taken from *(from Traditional Woodland Crafts – Raymond Tabor. Batsford Books 1994)*.

This simple process requires no capital, takes very little time, can be easily stopped, and requires minimal supervision. It is ideal for anyone with small amounts of wood waste not easily saleable as firewood.
1. Using a cold chisel prepare the drum by making five 50mm 92in) holes in one end, and completely removing the other. Knock up the cut edge of the open end to form a ledge.
2. Position the drum, open end upwards, on three bricks to allow an air flow to the five holes in the base.
3. Place paper, kindling and brown ends (incompletely charred butts from the last burn) inot the bottom of the drum, and light.
4. Once it is burining well, load branchwood, at random to allowair spaces, until the drum is completely full. keep the pieces to a fairly even diameter, but put any larger ones towards the bottom where they will be subject to longer charing.
5. When the fire is hot and clearly will not go out, restrict air access around the base by using soil piled against it, but leaving one 100mm (4in) gap. Also place the lid on top, lving a *small* gap at one side for the smoke to exit.
6. Dense white *wet* smoke will issue during the charring process. When this visibly slows, bang the drum to settle the wood down, creating more white smoke.
7. When the smoke turns from white (mainly water being driven off) to thin blue (charcoal starting to burn), stop the burn by firstly closing off *all* air access to the base using more earth, and secondly placing the top lid firmly on its ledge, making it airtight by the addition of sods and soil as required. The burn will take between three and four hours.
8. After cooling for about 24 hours the drum c be tipped over, the charcoal emptied onto a sheet, and graded and packed.

(**TransitionCulture** takes no responsibility for any burnt eyebrows incurred as a result of following these instructions, like always happens to me when I light a clay pizza oven!!).

There are also some good websites about charcoal. For example, there is a good site about english charcoal here. You could also use another barrel to make a smoker to smoke your meat (if you eat such…) and then another to make a barbecue, in which to use your charcoal to cook your smoked meat. All are handy skills that would be very handy to have tucked in your post-peak toolbox…

Categories: Energy, Food, Waste/Recycling

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9 Mar 5:01pm

Excellent article.

One little addition – people should be using axes not bowsaws – axes are very easy to sharpen and last 20+ years. Bowsaws are very awkward to sharpen and set and last less than a year.

For your free axe book from a revolutionary anti-industrialistation company, go to this link:-

Gransfors really do make the best axes in the world and have totally changed the way they do it, to make it more sustainable!

Jo Packer
29 Dec 9:19pm

An alternative charcoal making method can be found here. It uses black iron pipe and fittings and cinder blocks along with the oil drum…

[…] Re: Terra Preta – Today, 08:57 AM A FEW LINKS ON MAKING CHARCOAL Charcoal Retort Discovery Online, The Skinny On … Charcoal Renewable Energy Generation

[…] Re: Making Charcoal – Today, 12:06 AM I may have posted this before somewhere? but once again won’t hurt A FEW LINKS ON MAKING CHARCOAL Charcoal Retort Discovery Online, The Skinny On … Charcoal Renewable Energy Generation

8 Apr 7:48pm

another great way to make it at a small scale is to make a hole in the ground, the putting wood in it, lighting the bottom, and letting the air seep in from the ground. did it a few times. works like a charm

Marty B
8 Dec 8:19am

You wrote in April, 2007, that you dug a hole to burn, cook wood for charcoal. How deep? What kind of wood? Dry or fresh? I have mixed hardwoods that need to be cut and want to use charcoal as a soil amendment.