Biochar Retort

Hi friends! Old to permaculture, new to Permies. Been playing with cone pits (free technology, mediocre charcoal) but trying to emulate the “tin man” style for the optimal char and cheap design. Here’s the rub: I can’t find barrels that ARENT 55 gallons. Anyone here have ideas?

-places to check beyond CL or buying a brand new barrel?
-redesign to the Tin Man retort?
-new perspectives?

Thanks!

I found my barrel that is about 30-35 gals at an auction for $1.  It has a fitting on it that makes me think it was an oil barrel.  Initially, i had the same problem you are having finding a smaller barrel.  I used one for a while that I found at a scrap yard but it was only 8 gals, so it wasn't efficient for making any real quantity, and it burned out fairly soon.  I had some success just using a 55 gal barrel as a TLUD kiln, but I didn't like having to quench it with huge quantities of water and I ended up with lots of pieces that didn't char completely.  Like you, I wasn't too happy with the pit method.  I guess my advice would be make what you can with a TLUD while looking for a barrel.  They are out there.  If you have a scrap yard nearby, they often have barrels pretty cheap.  Sometimes you can find one at the Jiffy Lube type places or at a mechanics garage.  If you know anyone that welds, it's fairly easy to have a "barrel" made that is sheet steel welded into a cylinder and a square piece of metal welded on one end.

Try old galvanized trash cans - there are a few styles that are smaller than 55ga.  

Maybe a washing machine drum? it already has holes in it...

Dustin Rhodes wrote:Try old galvanized trash cans - there are a few styles that are smaller than 55ga.  

Maybe a washing machine drum? it already has holes in it...

I like the washing machine drum idea.  I wouldn't use galvanized metal for anything I was going to heat to high temperatures.  I was working with a friend on a project once and we were welding on galvanized steel.  It made both of us pretty sick.