A few questions from a prodigal son

I joined the site after the article about Wayne came out in Mother Earth News. Bought the book when it got published and built a Wayne Keith gasifier modified with an 8 inch fire tube with the intention of using it to power a generator. I ran a couple of test runs and just flared off the gas but never hooked it to a generator. I had no chunker of any kind and it was a lot of work furnishing fuel for it so satisfied that it would work if needed I set it aside. Then I burned down my shop and most of my fabrication tools. Being 69 at that time, retired and on the usual fixed income it was a struggle to get a new shop built and furnished with a minimum of cheap Harbor Freight tools. So it’s been quite a spell since I had the time to invest in gasification on any level. Now I’m interested in building an updraft charcoal gasifier that it would be possible for an on-line group for prepper homesteaders I’m involved with to build with basic fabrication skills.

It seems that most of the projects people were doing in this area were some years ago. I like the unit they built on Off-grid/pro but there are no recent reports from that group. I am thinking of something like the Troy Martz gasifier but again no recent reports. I’m wondering if those units somehow failed to work after further testing. I’ve tried to study what in the DOW forums but it’s information overload. I’m 73 now. Not sure I have time to read thousands of posts. I also like the Ben Peterson unit he put in his Mustang but that’s too complicated for my friends to build. So some of the questions I have are,

On the Gilmore simple fire units, how is the ash dealt with?
Why would someone use multiple nozzles if a single nozzle is sufficient to provide useable gas?
I’ve seen several videos that say a charcoal gasifier must have a full hopper before start up. Can a half full one be started?
My generators are hooked up for gas and propane. Does wood gas have to be pressurized to run it though the propane regulator or does some kind of by-past have to be created to pump it in past the regulator?

Probably stupid questions but give an old man a break.

Tom Holton. Northwest Michigan.


Welcome back to wood gas!
The regulator is not needed for wood gas as the engine suction is all you need to suck air through the nozzle which makes the charcoal glow to release the CO which powers the engine. You only need to fill it to the top the first time. After you use half the fuel just fill the top half again.


Tom, Welcome Back.
I am at the bottom of the list of doers here, but will give you my thoughts. A lot will depend on the engine size, use, length, and frequency of run you anticipate. I built three of Gary Gilmore’s SimpleFire gasifiers and they all work great. I do occasional short runs with small engines and small loads, except for the Toyota Corolla. You can check out that project on the DOW forum. Even the Corolla works well on it, but is only for occasional use, for runs up to one hour, maybe 30 miles, before time to refill. Minimal fabrication skills and tools limited what I could do. For the Toyota, I did get some help from a machinist on a couple of parts. I don’t experience a problem with ash or clinker accumulation, but it would be nice to have a clean-out port with the Toyota gasifier. Once or twice a year I scoop all the charcoal, etc. out of the Toyota gasifier from the top–a nasty job, but no worse than processing charcoal into engine fuel. Just some of my thoughts. Now the experts can chime in . . .


Hi Tom,

For preppers the type i build might be of interest.
The offgrid pro and the Troy Martz gasifier are based on this concept.

All these gasifiers work, but it is nearly impossible to make a living with a gasifier as product to sell.

The level of charcoal, maintained at a minimum height, serves the purpose of cooling the hot gas.
In my case simple pvc can do the job.

Have a look at it, its easy to build, easy to understand and a lot of cheap fun with it.
To be complete; it is based on the work from Gary Gillmore and became very workable with the valued input of the members on DOW.

I live and work in Thailand, teaching and helping with this concept to help others


Hello Tom, Welcome to the site.


Thanks for the welcome and response. The past few years I have been working on building an aquaponic greenhouse and moving as much of my food production into a controlled environment. In order to run an aquaponic system a source of power is required 24/7. Any grid down time will pretty much kill the fish and ruin many hours of work. That’s why I’m returning to gasification. I was an Ironworker for thirty years and started a residential building business after that. I can build a system at any level of complexity but I am mainly interested in working on something that my friends can duplicate. I have to say that all the discussion on nozzles is a little daunting.


The fun in sharing experiences i would say… and a lot we can learn from each other here on DOW

Nozzles; it depends what you want the whole system to be…
Even the best woodstove, coal fire, anything that haves to endure extreme heat… it wears down…
My observation so far: KIS, try to get the heat away from the nozzle-tip
In my construction the welds which holds the nozzle and the shape of the nozzle, allows the heat to dissipate towards the outer shell from the gasifier,
If i don’t weld strong, the contact surface outer shell / to nozzle body to small, the tip can easy melt away… ( i tend to go for high heat at its limits :wink: )


Hi, Welcome back! You were on before I started. I love these “wise” guys, what a collection of talent and character (in the classic sense): an oasis of sanity in an insane world!! :grin: we can agree to disagree about anything from soup to nuts, alpha to omega, and still remain friendly. Here is my input. What you are looking for functions as an “Un-interruptable Power System” or UPS. I am familiar with those. DIY, you need a very reliable energy source (or two) that can be called online with little to no time lost. A battery bank perhaps. That system is usually electricity as a final output. Then you need a reliable source of power to keep the system going long term. All of our mission critical electronics (at my employer’s TV station) run off a large high quality inverter. When the power grid input fails, an automatic transfer switch starts the generator. There is a flywheel energy storage system to keep the inverter running for the 20-30 seconds it takes the large diesel genset to come online. A more modern version would use a battery bank instead of the flywheel for this. Then, we have power until the generator needs refueled. An alternative fuel would be natural gas or propane. In your case yourself starting/ fueling a wood gas generator. You could also use a battery bank, running an inverter, to keep things going. I would guess you have some form of gas heat as primary, with solar heat and electric as backup to the backup.
Wow! how much hot air I have today! Wood gas generator as battery charger, heat source, electricity source. Solar as battery charger, passive heat source. Wind as battery charger, Wood stove as heat source, primary or backup. I say you have lots of choices! :laughing:


Hi Tom,
I’m probably dangling by a thread from the bottom of that list. But I have managed to get a 3KW genset running on charcoal.
I used a $20 angle grinder, a $100 welder, and I splurged on an 11lb spool of flux core weld wire for $44. The i960s generator came from Craigslist for $60. Someone gave me an old water heater and bbq grill that I cut up.
So, this is small, but I think it is a beginning.
This kind of thing is a lot like running marathons. You have to enjoy it or it will kill you.

TLUD for making charcoal


Thanks for the help guys. I’m a little familiar with high temps. My greenhouse is heated by a Rocket Mass Heater with a ceramic blanket line heat riser. I’ve just run from last fall to over the winter which in this area is long. I’m going to pull the barrel off that soon and make sure it held up well before we start another heating season. We had our bank account hacked a few weeks ago and it was kind of a mess getting that straightened out so my wife will have a fit if I order off Ebay but I’m thinking I’ll buy some of the silicon carbide tube you guy discussed in the nozzle thread and see how they hold up. I’ll probably stock up on TIG cups as well and experiment with both.

I’m one of those End Time wackos, Mike so I don’t think that the grid will be around and I don’t think that PV is going to work for quite a while in the future. I’m planing to move most of my food production under cover and even if things were not as bad as I imagine, I live about 6 miles in-land from Lake Michigan. We have such dense cloud cover here in the winter that there is not enough light for in-door growing as it is. Right now I’m set up for running a thousand watts of LED grow lights for 12 hours a day. I consider that minimum for decent production. That is a fairly large load. The plan for off-grid is to run a generator six hours a day and run off a battery bank for six. There is some question about whether I can keep a bank of batteries with that kind of draw charged with a six hour run time on the genset. I have very little experience with off-grid power so there is a big learning curve involved here. Also running a gasifier fueled generator six hours, seven days a week seems like it will take a lot of wood or charcoal. I have an endless source of wood but not sure if I have the energy to process that much everyday. We’ll see.
Good looking job on your gasifier Rindert. Very regal painted purple. I should put something like that together to learn something before I try and convince my friends that I am worth listening to at the homestead site.


Hi Tom , if you buy 1 of the thick wall Hexoloy tubes you will not need to buy the Tig cups to use for nozzles , these silicon carbide tubes will last and last.
i mounted mine into 1 inch too 3/4 pipe reducer and then used a 3/4nut to tighten it onto my drum to make a air tight fit and then ground out the thread on the 1 inch side till the tube was a nice plug fit into it .


A 7 years useable durable self standing system is not wacko.
A real challenge to do.

Great self-evauation on your specific climate, local, and personal capabilities.
Ha! Ha! Wackos cannot do that!
You seem pretty practical goals orentated to me.
Steve Unruh


Raw wood generator fueling gasification is what Ben Peterson’s book system was about.
A new sitting room couch for the wife had me forced to books/magazines stacks cleaning up and I surfaced a buried extra Ben’s book copy.
PM me a safe mailing address here on the DOW and I’ll mail it to you.
Ha! Just the book. No preachin’ from me. Promise.
Steve Unruh


Hi Tom, Running a generator on woodgas or chargas is relatively easy. The issue will not necessarily be how much wood you have access to, but rather, how much time do you have to prepare the wood for gasification? Wayne has a sawmill that produces material that is easily chunked up and a climate that can dry them out quickly. Charwood needs processed into certain sizes (based on your charcoal kiln) and dried to 20% moisture content. In PA, (and I’ll bet Michigan is similar), this can take several months to a year. What I’m getting at is you may find the time and energy you put into making all this electricity to grow plants in winter is not worth it. But then again, maybe it is. You will have to make that decision. If you want some real world experience in woodgasification, you definitely came to the right site.
As for nozzles for a charcoal gasifier, the Hexoloy tube Dave talks about is very durable. He has put many hours on it to know that it works well. I like the water cooled nozzle as it allows me to easily put some steam into the oxidation zone. The hot water could also be circulated for other uses. What ever you decide to do, we do not look on you as “wacko” as we are are already accused of that :slight_smile: Let us know how you proceed down this path of self sufficiency, it will be needed. Just yesterday a friend of mine was told by a local banker executive that the economy will probably hit a major stumbling block which he predicts will be the later part of this year. Things are getting interesting, and not in a good way.
Take care and until later,
Gary in PA


Wacko = Anyone who tries to run an engine on wood.


Steve U. Thanks for the offer. I have the Ben Peterson Bible. They are no longer available, at least on Amazon. I checked to see about getting his carburetor book. Out of print but some one will sell you one used for about $850 bucks. You need to hold on to the book you have. It will be very valuable soon.

Gary. I have watched all your videos. I am subscribed. Very enjoyable and information packed. They reason I never followed up on my current gasifier is exactly that it was just so labor intensive to produce fuel and I may be a prepper but as long as the grid is operating I’m a big fan. Without electricity, the future is bleak in my opinion. A lot of people think that if the SHTF will be just going back to how things were in the early twentieth century. I don’t think so. However the area I live in did not get power except in towns until after ww2 in most areas. My great uncle ran his farm with two Jacobs wind generators and he was the only one with lights and power for miles. This was in the thirties. It’s absolutely doubtful I’ll be able to accomplish my goals of self sufficient food production in a controlled environment using wood gas unless I get a lot of help. More help, more mouths to feed so diminishing returns on that but people that are heavily invested in PV are going to be shocked by whats coming that will make their systems non-functional and everyone I know that is using wind has as many problems as benefits from it. At least with producer gas you are in control if you can make fuel and maintain an engine, so I see it as the best power alternative to the grid.


Welcome to the group. :slight_smile:

Are you using charcoal filters for the aquaponic system? If so, it might make sense to start making charcoal. Activated charcoal is essentially charcoal exploded with steam… (you don’t want the water in engine charcoal, and it takes forever to dry it, but the retort and process itself might be dual purpose.)

What is your wood supply? That will make a difference. Consistency in fuel size important. If you don’t have a wood supply, and your friends also don’t have a wood supply @Matt Ryder works on pellet based gasifiers and is in Michigan. He also has an automated control system. And a heat exchanger system, that could be used to supplement the rocket stove heater.

If you have a wood supply but it can’t be made consistent, charcoal is probably the best way to go, because you post-process the charcoal to a consistent size without quite the investment in a chunker.

Keep in mind, because of the lower energy value of the wood/char gas, you are looking at less the 1/2 the output from the generator.

Honestly, because you need reliable service, and most power outages at least around here are only for a few hours. I would probably look at batteries. Then piggyback the woodgas on the back to recharge those or directly power the inverter they use. It also depends on how much electric you need to sustain your system. But some of the new LiFeP batteries can do like 5000+ charge cycles, and beyond just being a backup energy supply, you might be able to leverage it to actually save money in your whole system because I can’t imagine your electric bill is low…


There are two Cross Fire Gasifiers for sale here on the site. @toddharp You may want to get a hold of Todd Harpster

Ive built and developed direct wood gas systems for over 8 years. I have built some of the most advanced systems of their kind. If you go with direct wood gas, I would build a retort and cook your fuels down a bit. If you can do this reliably, you dont need to turn it too charcoal but cook out all the moisture. You are guaranteed to never have an issue and the machine will flow and run much more reliably with a less complex system.

The other option is to go charcoal. Processing is less labor intensive but you lose a bit of energy density from raw feed stock to usable fuel. If you use process heat for other things this will help reduce this loss and water injection or flash steam injection will replace some of those losses as well.

I did a tutorial here in the site to build an auto mixing electronic valve. This controller is now well proven. It is free

I am in Muskegon Mi. you are welcome to the shop anytime.


OK, you have been sand-bagging us a bit. I don’t blame you, lots of bad information and folks with bad intent on the web. You have done a lot of homework already, probably way more practical off-grid stuff than me. here is my take: yes, it is more than likely bad times are coming. God is good and He will give us as much time to repent as he can. He really doesn’t want to loose any souls to the eternal darkness. :innocent:
So, what is a man to do, to provide for his family, and his neighbor? Continue learning how to live life without the “System”. Study the old ways of food preservation, that still work. The Amish are a bit out-there, but they know about preparing for bad times. They prepare their own reserve supplies, and act as their own insurance company, pooling labor and food and resources and knowledge when bad things happen. Teach trusted others what you have learned. We don’t know if the world will end in fire, or in ice, or how long it will take, or if we will even still be here.
Don’t believe anything you see on USA network television. I see the lies everyday. Enough said, seek out truth, wisdom in many trust-worthy places.
Learn to live with less. Learn from “Great Depression” survivors. How convenient for the bad guys that most of that wisdom is gone now. Remember, don’t erase your / our history. We need it, warts and all, for learning.
edit Reduce your debt anyway you can. Pay off loans. Fix the old stuff that is made to last. Buy local. Support your neighborhood businesses. You can’t possibly store everything you will need, it will be a barter system economy.
West Michigan: :smiley: Beautiful, my favorite vacation spots are there. I grew up just North of Detroit, now I’m a Hoosier. Staying here. Blooming where I’m planted.
To whom it may concern… Mike R.


LOL. That’s just the epoxy coating that was inside the water heater. You can’t burn it with a propane torch. Not bad though. It has kept the steel from rusting. I have thought that maybe I should get some of that and coat high temp things with it. But probably very poisonous. Making a big (50gal) TLUD from the tank. Going to fire it probably tomorrow and see how it works. Chunking all that wood by hand was a bear. I’m beginning to see that a chunker is sort of central to any woodgas system.