Wood chips

HI all, another question that has probably been addressed, will the W.K. gasifier work with wood chips? If not are there any modifications that can make the chips work? I have a 3pt chipper that will take up to a 6’’ log. This wood be a lot faster for me to make fuel. Thanks Al

I have chipper envy, my GEK Gasifier runs on wood chips.

Good morning Al,

I think chips will be more likely to bridge vs blocks or chunks.

If I were going to try chips I would reduce the restriction size of the gasifier ( smaller choke ring) to compensate for the huge surface area of the chips and use a mixture of chips and blocks until you get a feel of the system.

Six years ago and on an earlier design gasifier I added in about 15 gallon of chips and drove the truck home ( about 25 miles ). When I tried to start the motor the next morning the valves was stuck and I bent pushrods.

As others, including me have said, there are wood chips and then there are wood chips.
In my amateur opinion, you would almost never run wood chips without sorting them first. You need to remove the long things that certainly cause bridging and then you need to remove the “fines” which often include a lot of bark (very bad from a tar standpoint), the very small chips, and dirt.
Many wood chippers that I have seen produce chips that are generally too small. I keep chips that fall through a 1/2" X 1" screen. I have friends who have wood chippers in the 8HP disc (3" max) range to a 25HP drum(6" max range). Even when chipping only branches over one inch in diameter, the bigger chipper only makes about 20% chips that I can use. The 8HP machine is worse.

Take a look at this Greg Manning video.

He has a pretty good process going and has been at it for many years.

I have been gathering commercially made wood chips; those produced by disc chippers that take whole trees. Even then, I absolutely have to dry and classify (sort) the chips before use. In my experience, drum chippers make smaller chips that do disc chippers.
I had thought that you could adjust the knives to produce any size chips you want, but the commercial guys don’t want to do that, and, it isn’t clear from the couple of manuals that I have seen that it’s a good thing to do anyway.

You can see a few videos I have made on this subject on my youtube channel (most of which I have already reported here):

Gary Hoffman, I’d like to hear more about how you prepare wood chips and how they are working in your GEK.

Pete Stanaitis

this what we run in our little gasser

The smaller the wood you are using results in less volume for the gas in the reduction zone. I have been using a different batch of chips in my gasifier that are smaller than I have used before. It does not work nearly as well, the larger the engine you are using the more it is effected by this. The gas needs to spend sufficient time in the hot charcoal to break down the tar. the more space between the pieces of charcoal the more time it takes to draw through.

thanks everyone, that makes sense.thinking now about modifying my chipper to make chunks.

Hi All
Some recent interchanging about using wood chips for vehicle gasiffiers being put onto Matt Ryders Harbor Freight Open Source Chipper topic.
Maybe the vehicle intended parts of the interchange could be transferred to here.

There are chips, and there chips.
Most fuel wood chipping has been done for stationary use.
Good info on that has been vidio put up by Gregg Manning/Canada. And StephenA in New England. Older stuff out of Europe too. Dutch John was sceening his made-for-him fuel wood chips into three different size/weight categories to be dedicated to each size class of his gasifiers.
Basically for the best fuel wood gasifier chip you MUST watch what you put into the chipper. NO leaf, needles, twig ends. WYSIWYG!!

Some work at the VictoryGasWorks was gone on viberatory table screening out “free abortionist truck loads” of mixed crap. Pictures of this in BenP’s DIY Build-a-gasifier system book.
Bottom line is you will only get a usable yield of 20% to 60% out of each truck load of “free”.
So unless you have a big rural property to absorb landfilling the twiggy, stringy, leaf-needle, bark crap percents rejected out, you are setting yourself up for a tons and tons, cubic meters and cubic meters bulky disposal problem. Your wife; your neighbors will hate you.

Best way to make gasifier Fuel chips means hand labor pre-processing the limb, trunk stocks going into the then special set up to-make-only-large-fuel grade-chips, chipper system.
So . . . yes chipped fuel stocks can be made.
But far from no-labor, free.
And then like ChrisKY: I’ll say did you fuel that chipper engine on Dino-cheat? OR woodgas fuel?

Steve Unruh


The best chips I made was sawing on the mill into boards then air dry next chip. The shape and size changes the chip and also moisture content, or it did for my set up. Sold the little 3pt 6" chipper a few years ago and the monster saw mill size chipper last year.

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Yes. Exactly my points.
You did not put leaf-needles, twig ends into the process.


Like I said you got to de limb your limbs!!! haha. and then the larger the feed stock the better chips you get. What I plan to do though is not use limbs and poles for processing. But to cut and spit logs down to a size that will fit into this little machine. The whole intent with the HF machine is not so much that its a chipper but that it is a premade made machine we can get at a relatively low cost. We already have enough stuff to build, sometimes its just easier to just go and buy it.

I was looking three things I was hoping it would be. Cheap, well made, a good engine and that it made a decent heavy chip. It meets all these requirements and is one of the good buys from HF. The log splitter is also getting good reviews so Im looking at getting it too. But no not at all easy labor free, there will be much processing to make this work.

Pete have you tried a hopper shaker system, this might help you run less screened fuels.

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