Any way to test gas production before buying truck? and other questions

Hello to all,
I finally got started on my gassifier last weekend and finished welding all the blades on and the fire tube and the top plate this weekend(I am a college student and only get to work when I go home for the weekends). I have a truck now but its an old 86 chevy with a carburetor and I am planning on buying another truck with a mpfi for the gassifier. As I am on a college kid budget my dad who is helping me fund my project would like to see the gassifier produce some gas before spending money on a different truck. Does anyone have any experience/suggestions/ideas on how to economically test the gas production on the gassifier before having a truck with specific dimensions to form it to? I would be willing to do some re-cutting and re-welding if necessary but don’t want to have to completely change it to fit to whatever truck I choose to buy.

Also, we try not to burn pine through our wood stoves because of the tar and sap that comes from it but I see that other people on here run it through their systems, is it safe to run Pine though the gassifier without having to worry about the sap and such?

Finally, I am trying to use a stick welder(Mistake) to try to save money because I already owned one and didn’t have 500 bucks to put into a mig. Does anyone have any tips in particular for welding the thin barrels with a stick welder?

Thanks in advance for all the help and support. Hope to get this done before I turn 19!

Hello Walker and welcome to the site .

If you can flare the gas and maintain a flame that is hard to see in day light it will run a motor. As long as it is invisible in daylight it should be clean .
I usually can tell just by looking at the existing gas but it is a little harder to explain .

I use about 95% pine and have had no problem. ( used about 60 pounds of it today )

I have built a few gasifiers and welded the thin drums with a stick welder but wouldn’t want to do it again . My suggestion would be using the smallest rod you can get and cleaning the welding surfaces .

If you do buy a mig you will never look back !!


to D.O.W. you can check your gas production by using a blower instead of an engine, ( check out Wayne’s International tractor build). I have welded car body metal with a stick welder using the smallest diameter 6010 rods moving at a fast pace. Practice on some scrap till you get the hang of it. Good to see young people interested in wood gas. Al

Where ya from? There maybe someone with a gasifier within a reasonable distance for you to be able to see, touch, smell, and get dirty.

I’ve done stick welding for 30+ years, and there is no comparison. Mig with CO2/Argon gas. Buy it and sell it when you’re done building. Decent ones can be found for $350. I’m sure others will chime in as we are now “consumers” in the welding business. And welcome, and good luck with school and WG.

And thank you, Wayne, for the tips about flaring. I watched you flare your trucks before where you said, Yep, that won’t stay lit, but that will run the truck." I was wondering about what kind of flare quality I would need to run my truck. Last time I flared it, it stayed lit for two hours until the fuel bridged. In darkness it was a clean blue flare. Maybe I’m ready to mount my system to my truck? I’m about to hook it up on the ground and see if I can get the engine to run.

Also, Walker, you can make different size inserts to change the restriction size and the distance from the nozzles to the restriction. I’m sure Wayne can tell you all about that. If in doubt, build big and you can then make it smaller quite easily afterward. For example, Herb Hartman and his wood powered Cadillac runs his gasifier with 18" from nozzle to restriction.

If you need any advice about what not to do, then I can give you some. For example, don’t try to save money by buying a flux core welder like I have. It’s better than not having a welder, but it is frustrating to use. Like Carl says, buy a good used MIG and sell it when your project is done. Flux core welders will have no resale value.

Burn, Baby, Burn!

hmmmm… while i have a proper mig welder at my disposal now i’ve built quite a bit with a flux ore machine… i believe its all about how you use it

Walker: Try moseying over to your school’s Welding Dept. and ask around. There might be someone with a few MIG units that could either let you use their unit (at their place), borrow one (with collatoral/agreements etc.) for cheap/labor, or maybe sell you a decent used unit for cheap.

OK, you challenged me a bit, Arvid. Yesterday I watched some tutorials on my flux core and how not to MIG weld. I wondered if I should just buy solid core wire, since it’s cheaper and my flux core welds seemed to be over oxidized anyway. I got to see what a MIG weld looks like without shielding gas. Wow. Looks nothing like my welds and a lot like moon rock. OK, my flux core is working to mostly shield the weld.

One of the videos about my particular $90 welder mentioned the recommended extension cord gauge and length. That made me think that I am using too long and too thin a cord. Maybe the voltage drop is causing weakness so that the “high” setting becomes “medium” and the “low” setting becomes “weak.” With my current setup I cannot form a puddle on the low setting. The metal just forms a bead with no puddle. Not enough heat. With that in mind, I began using the low setting to just add metal, and the high setting to weld with. I haven’t tested it with a voltmeter yet, but if this is true, that would explain why I could never weld well with the low setting on my welder.

Oh, and I changed the plastic shield on my welding helmet today. Now I can actually see what I’m doing.

Thank you, Arvid O for the encouragement.

yup, i find being able to see very helpful. get good welding like that and MIG will be a breeze. i will add metal prep matters if you want to make water tight welds with flux core,a wire brush cup on a grinder is your friend.

Brian, the different heat settings are for various thicknesses of metal. On low setting, thick metals will not melt fast enough and you’ll get a standing bead like you said. On thin enough metal, it melts much faster and forms a proper smooth bead. On too thin metals, it melts faster than you’re adding metal, and you’ll just poke holes in the metal. That’s why expensive welders have so many heat settings, or continuously variable switches.

Flux core works OK, but if you ever get the chance to weld with MIG you’ll never go back (willingly). It’s more expense with the shielding gas, but the wire is cheaper. Really worth it for the weld quality.

and i agree with Chris… if you can use MIG you will like it and not want to use anything else. That being said, there isn’t anything being done today that you probably couldn’t use a stick welder to do… newer processes are just easier.

I would use 3/32 6011 rod seems too have less flux getting in the weld , just weld one side should be enough/about 1/4 " apart/ you might have too use 1/16 th rod if your finns are thinner/ my finns are about 3/32 thick soft iron.havent welded mine on yet either,

So I plugged my welder directly into the wall, removing the 100’ 16 gauge cord. Well, I was able to weld two scrap pieces of pipe together fairly nicely. I even burnt a hole through it. That was on the low setting.

I fancied myself to be a pretty decent stick welder; now I’m having to learn some MIG skills. Stop blaming the machine.

Thanks Arvid. And good luck, Walker.

100’ of 16 gauge extension cord powering a welder? Aren’t cables of those dimensions only rated to about [email protected]?

I used a 25’ long 12 gauge cable on my little 120V Hobart and the extension cord would get noticeably warm after a bit of welding on Low-Medium (“2/4” voltage, “30% feed speed/Amps”)

Use 6013 rod 3/32 dia. Set the welder at 60 volts (it will be a little hard to get the arch started but less chance of burning through) 70 will weld better but have a tendency to burn through. When welding thin material move the rod from one side of the weld area to the other. Only weld for about 4 seconds then lift the rod for two or three seconds. Then go again. When welding the cooling fins on the tube---- concentrate your weld on the tube, beside the fin. The move the weld back and forth on the tube and let it just touch the fin and then go back the other way, You should get just enough weld on the fin this way with out burning through. Burning through occasionally won’t hurt, but try to avoid it. Also you can weld straight down beside the fin, concentrating on the tub, but tipping the rod towards the fin and then tip the opposite way. Cleaning the material before welding and wire brushing after, before a second pass makes the weld go much easier. If you are using banding material , it might be good to hit the face of the material with a grinder first. The paint on banding material is like a power coat and does not take a weld very good. Preparation, preparation preparation. Oh, I almost forgot, tip the rod about 20 degrees from vertical in the direction you are moving the rod.TomC

Well, Brian, different length extension cords have proven for me to be a way to control the heat a little more than stock.

I never thought about the amperage rating, and I never noticed a hot cord while welding. I mostly welded on high with the cord, since low was too cold to do any welding.

Burn baby burn.