Minimum Amps for Air Arc Gouging

[woodlandfarms]

Was looking into this for a project instead of trying to get the steel seperated with grinders and cut off wheels. All I have though is a AC/DC Lincoln Tombstone which is 225 AC and 180 (?) DC. And what kind of air is needed? I have a 40 gallon...

 

[Shield Arc]

You might get away with 1/8-inch rods. I think the smallest I've ever used was 1/4-inch.
I always liked 400 + amps, with couple hundred pounds of air, but I was always in a hurry!

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[Gary Fowler]

I don't think your Tombstone Lincoln's duty cycle will allow you much time to air arc, but then again neither will your air compressor. You need a lot of air volume to do that and not many home duty air compressors will get above 135 PSI. I don't think either of your machines are capable of doing arc gouging.

 

[woodlandfarms]

Thanks guys. I didn't know much about it so this all makes sense. Will head to Harbor for some cutoff wheels.

 

[stuckmotor]

I tried arc gouging with my AC Tombstone and an air gun hooked to a Harbor Freight compressor. The results were disappointing.

 

[yomax4]

The way the tomstone is built, You would burn out the heat selector by doing a wide open dead short. Rule of thumb..350+ amps to carbon arc with a machine that is not wired up like a tombstone.

 

[Arc weld]

Your machine is way too small and light duty for gouging. You can get lighter duty gouging torches that only need about 8 CFM and can run 1/8" gouging rods but gouging is really hard on a machine. I worked in a shop that did chromium carbide overlay inside pipe for the oil sands. They used flat carbons to gouge the hardfacing off when welding elbows together. Lincoln SAE 400's are one of the most heavy duty welders ever made and this shop had a couple sitting in the corner that were burn't up from gouging. You can see the cables jump when you strike an arc and can feel the current going through if you hold the cable while someone is gouging.

 

[Shield Arc]

I don't know what the cheapest plasma cutter that can scarf would cost. When taking out a weld I would much rather use a plasma than a carbon arc torch. Scarfing with a plasma reminds me of watching the surgery channel when they're doing laser surgery. Now if I wanted to hog off a bunch of iron I would rather use a carbon arc torch with the flat rods.

Here is a weld I took out with my plasma.

 

[Gary Fowler]

Before they had plasma torches and the like, we used oxyacetylene torches with a scarfing tip to remove old welds when we didn't have access to an arc gouger. Slow and hot, but it got the job done. Never used a plasma for gouging, only cutting, but it doesn't look like you have good depth control with it like you would with carbon arc or even scarfing tip on a torch.

 

[Shield Arc]

Oh it's a lot easier to control the depth with a carbon arc torch! With a plasma you control the depth with angle of the torch, or amperage.
I haven't used a scarfing tip on a torch in years.