Dumber Idea: Hillbilly shielding gas: compressing exhaust

[dehved]

I can't afford (or drive to get) shielding gas. The things I have a surplus of is trees, electricity and empty cylinders.

I just bought a combo gas mig/tig chinese job welder. I'd really like to play with shielding gas to weld thinner materials and get away from impregnated flux imperfections.

Reading up on 6010 rod flux, I found this on the wiki:

A cellulose electrode is a welding electrode that has a coating containing organic materials. About 30% of the coating weight is cellulose. In some countries, paper pulp and wood powder are added to the coating in certain ratios to reduce the amount of pure cellulose.

The organic compounds in the coating decompose in the arc to form carbon monoxide, carbon dioxide and hydrogen, which increase the arc tension and thus, the welding arc becomes stronger and harder.

I've also been playing around with a wood gassifier to power a generator, with tarry results (that lead to grid power being hooked up) and rocket stoves and whatnot.

So the big dim lightbulb moment happened: Why not compress fully combusted (and cooled, dried) rocket wood stove exhaust into an air tank, then use it for real hillbilly MIG/TIG.

Not the smoky tarry exhaust from gassifiers/old stoves, but the kind of clean exhaust from a clear steam type of slightly oxygen starved (some CO but no O2)
rocket stove/catalytic type of fire. In theory this should create products of combustion similar to burning cellulose (read: wood) without the hydrogen and CO as this should be fully combusted CO2 and water with some CO on the razor's edge of a burn.

Thoughts on the state of my compressor's reed intake valves aside... ?

 

[Maker Mike]

Hey, necessity is the mother of invention.

 

[Ironman]

The steam part of it means trapped hydrogen in the weld metal. I think engine exhaust would be better, but with cat converters there is little of that and more water vapor also. It will be interesting to see how this works out

 

[dehved]

The steam part of it means trapped hydrogen in the weld metal. I think engine exhaust would be better, but with cat converters there is little of that and more water vapor also. It will be interesting to see how this works out

should be no steam, condensed out with copper heat exchanger while cooling.

I read co2 blends are used for MIG proper, argon for tig, so maybe not TIG for this? I was thinking of dipping hot steel fill rods in borax flux like when brazing, so gas would just be to keep the tig electrode from burning itself up.

 

[Dan Dubeau]

I'm on the edge of needing a mig gas refill right now, and will probably run out before I finish another set of wheels. Hurry up and figure this out for us, so I don't have to drive into town would ya .

 

[dehved]

I'm on the edge of needing a mig gas refill right now, and will probably run out before I finish another set of wheels. Hurry up and figure this out for us, so I don't have to drive into town would ya .

Just reroute your car's AC compressor to a copper coil to the exhaust manifold, from the compressor to the empty tank, lol. Full by the time you drive to praxair.

 

[Dan Dubeau]

Just reroute your car's AC compressor to a copper coil to the exhaust manifold, from the compressor to the empty tank, lol. Full by the time you drive to praxair.

Done that, I'm getting sleepy, maybe have ran the hose wronhhsfffffffffffffffffff

 

[dehved]

I guess anything is possible with enough wasted time. Probably best to stick with stick in the sticks.

 

[mickeyf]

This sounds to me like the kind of thing that would likely fail spectacularly the first time. But then, if you carefully and scientifically persisted, tweaking one variable at at time, documenting in detail what improved your results and what things made them worse, then after enough years had passed you might actually come up with something that was reasonably effective. Of course, this would be at many time the cost of simply using the tools the well capitalized welding equipment companies have developed over that past 100 or more years of welding research...

But hey! What do I know? And if you document it all on Youtube...