Hi All,

Here is a sneak peek at the progress… Jared did an awesome job of reworking the bucket lids, gaskets, and trailer modifications. I wish I was there.

Over the weekend, we got this project started, ran into and worked through many small challenges… I won’t be back to help finish it until Thursday. I have a feeling I’ll miss the first flare.

More updates in the coming days… Thanks guys!


It looks pretty damn good! You should have some good,long runtimes with that tank. What kind of filter are you going to use? Hay or foam maybe? What kind of method are you going to use to make charcoal? A retort or maybe a TLUD barrel? Anyway looking good, keep up the good work.

Thanks Jonathan!

We’re using a 2-stage filter… 1. cyclone, 2. open cell foam rubber with a wool blanket on top. The second filter lives in a 5-gallon bucket.

For now, we’re using a TLUD, double barrel retort (55 gallon steel drum + 30 gallon steel drum), with insulation on the outside and top, along with a double-wall chimney… Should be pretty efficient. As for the grinder, we’re going with a steel bar with welded bolts. In fact, it’s being built today. We’re filtering the sizes though a duel-screen sieve… 3/4" on top of a 1/8" … the fine stuff falls through the bottom sieve.

The ideal scenario would be to turn the 3’ x 4’ square sieve into a rotary trommel, and built a chute from the charcoal processor down into the inner trommel tube (the 3/4" screen). whatever falls through the the 3/4" but doesn’t fall through the 1/8" screen is perfectly sized feedstock, and will ride it’s way through an auger to a feedstock bin. I really want to build this onto the trailer – maybe as a tailgate that folds up??

Once the feedstock is in the bin, our unit will be able to vacuum up the feedstock directly into the reactor. This is done with the cyclone filter by unplugging it from the 5-gallon catch bin, and plugging it in to the top of the propane tank. We already tested this last weekend… Works like a charm! my only concern here is that the perfectly sized feedstock will get banged around a bit and turn into slightly smaller sized pieces… We need to test this theory too.

As for the batteries that you see – unattached at the moment… the plan is to build a mobile power station inside of a diamond plate tool box (with a lock)… Similar to the attached photo.

We still have a bunch of testing and tweaking to do yet, and haven’t even flared off yet… So, although we have a bunch of wishlist items for the “power trailer,” I don’t want to get ahead of ourselves. First and foremost, we need to dial in the gasifier, and get it humming.

All good fun!


Looking great… lovin it

Hi all,

I can’t believe it worked so good… I demonstrated the unit in front of 30+ people at the Baja Permaculture Convergence this weekend. We literally finished the build at the last minute, and I was prepared to give excuses on why it wasn’t “quite ready.” or, that the generator was old, and needed to be tweaked. But it worked, and worked very well! I was able to a get 2kW load on a 4kW Onan with CO… Everybody clapped, and cheered… very cool moment. Videos will be coming in the coming days.

However, there were several problems when people weren’t around, and I am trying to get to the bottom of it. I also did something very stupid, and had my first KABOOOOM! event.

Here are the problems:

  1. After two different start-ups, I was not able to produce good gas any longer, and my third attempt yesterday, for a few friends was not successful. I could never get a flare. The smoke would not ignite. I have some ideas on the problem, but wanted to ask the DOW members about your thoughts.

My ideas:

– A large proportion of ash accumulated after two start-ups, as I let the charcoal smolder out on shut-down, perhaps the charcoal burned for many hours afterwards, and left a bunch of ash in the combustion zone???
– I filled the propane tank to 3/4 full and then drove 50 miles to the convergence. All the bumps and vibrations may have stratified the charcoal sizes. The tiny bits (1/16th of an inch) moved it’s way down, and the large pieces (almost 1 inch) moved upwards.
– Instead of making my own charcoal, I purchased large sacks of carbon, here in Mexico. It’s the same stuff they use to BBQ chicken or beef… It looked pretty good to me, and I didn’t see many un-pyrolized pieces. However, they also didn’t have that "clinky glass’ sound when I dropped them. Perhaps they weren’t fully done.
– The flare was not pure blue… This was a bit of a shocker… The flame looked very much like the wood gas flares I made before the switch to charcoal… The flame was blue with a mixture of that “Halloween orange” color. To my previous point, maybe there were some hydrocarbons left in the carbon???
– As I mentioned, the third try was a failure… I noticed a lot of condensate on the cyclone. My cyclone is plastic (Dust Deputy brand) and I saw beads of water on the entire surface… I did not see this before, but I also didn’t look for it.

Any insight would be most welcome… The flare didn’t ignite, and the engine would not turn over, but there was smoke.

  1. After the successful demo, I turned off the blower, closed the ball valve to the nozzle, and just let the flare burn. It was cool to watch a lazy flame just burning… Instead of blowing out flame before i disconnected the hoses, I started to disassemble the system with the flame going. DUMB! Oxygen quickly made it’s way into the system, climbed up the pipe to the flare assemby, and the flame ignited the gas, which then made it’s way down to the final media filter bucket and blew the whole lid off! It sounded like a shotgun blast, and my wife jumped out of her skin. Luckily nobody was hurt… except my pride.

I now understand the full repercussions of letting oxygen into the system. It will forever be scarred into my memory, and will approach this safety issue with full respect, as it deserves.


Because of my explosion event, I’ve decided that an open-source gasifier – made with off-the-shelf parts and no welding required – would be a bad move. I’m intent on doing an open-source gasifier, but one with metal, and plenty of welding… Emphasis on safety. I can just imagine someone building one of these without knowledge of fabrication, gasification, etc. I don’t want that on my conscience.

So, we’ll treat this as an inexpensive prototype that precedes a fabricated unit.

One thing is for certain… It worked well that night, and I am smiling.


Hi Troy, congrats on the runs and welcome to the kaboom klub too. Problems,…
I learned that other peoples versions of charcoal differ greatly from mine and the lack of brands is an imperfect indication of it being done as evidenced by the yellow flame. Imperfectly done charcoal is better for cooking as it imparts flavour so never trust it. Next on the list would probably be low was the charcoal level in the hopper? More then 1/3rd empty and all you will get is smoke. Same goes if the pieces are all too big… Have fun just hope you didn’t inject too much tar into the onan’s valves…
Best regards, David Baillie
PS here a preview of my new tractor unit

very cool

Congratulations on getting a couple of good runs in with a crowd around Troy.

David, hope to see a lot more details on the tractor.


As already stated by David B, also based on my own experiences, the sizing of your charcoal is to coarse.
For the 4 Kw Onan, your biggest pieces should be max 1/2" with a max content of 20%
60% should be between 1/4" and 3/8", the rest 20% between large dust and 1/4"
Hence, if you make everything smaller then 1/4" all will work well…

to know about the charcoal quality, i put a transparant plastic pipe filled with a white cotton cloth in line with the suction hose.
It gives me the knowledge about the presence of “Tars” from uncooked charcoal and indicates the amount of soot passing trough.

Congrats any way and welcome in the Club :wink:
( i keep my mouth shut about boom’s )


Hi Troy, Usually your first run in front of an audience is a failure. Congradulations!!! Now on to your problems. Do not use commercial barbeque charcoal. This stuff is burned very slowly and contains lots of tars. This increases the weight and gives off “flavor”. I burned some mesquite bbq charcoal in my forge and “Look out!” Sparks were flying everywhere and the flame was a bright yellow. Probably due to sodium in the tree. Make your own charcoal and make sure it is well burned. There should be no yellow flames present when you shut your charcoal production down. This indicates all the volitales have been cooked off.
I"ll concur that your charcoal bed has settled and thereby is restricting gas flow. Also make sure you do not have any air leaks. They are a real power stealer.
When you shut down your gasifier make sure you shut off ALL places where air can enter the reactor. Especially the intake nozzle. That charcoal will burn for days if you don’t.
Welcome to the KaBoom club. use a shut off valve next to the flare to shut off the flare. What I’d give to see Wayne dash for cover.but have done so myself.
Hope wifey isn’t too scared to let you continue with this madness.
Gary in PA

about the “kaboom”…
try to avoid building “stronger” then needed…
i use soft plastics and soft silicone to ensure that i have plenty “pop off” valves…
vacuum, yes
pressure: a little above zero and it pops

your “kaboom” also indicates the presence of plenty “hydrogens” since the flame speed of pure Carbon monoxide is so slow that you can outrun it :wink:

making things more strong, fool-proof, is ok, but make sure to counter pressure build ups with proper “pop off’s”
otherwise a bigger bang then only a bucket lid could occur.

Apologies for the long delay… I moved my family down to Puerto Vallarta, and this last month has been rather hectic. I’ll attach some photos of the build on following posts.

Although this is just a rough diagram of the latest design, the components are pretty much the same…

Here are some photos of the fabrication of the OpenFire… We’re about a week away from firing off the first flare :slight_smile:

Wow, looking great…

We built and installed a 10.5 gallon, aluminum water tank, with a water drip system. We used copper tubing (5/8th in.) this time around, but may switch to stainless or aluminum in the future, and maybe larger diameter tubing, depending on testing. Copper was easy to find… We’ll probably have some future revisions to the steam outlet as well… This is V.1.0. lots and lots of testing :slight_smile:

Sorry for the sideways images above…

Lots and lots of physical runtime is always best. Beat it up real good! Good luck. Would like to see so hard numbers with and without steam. Constant load, charcoal consumption etc.
Best regards, David Baillie

yup, what David said. Keep up the good work Troy. I didn’t even really want to show people our system too much until it had a couple hundred hours of run time on it.