Cutting with a arc welder?

You're talking about arc gouging. Aka "scarfing".

Ernie says you can soak 6010 rod and use it to cut plate steel with. This one I'm going to have to see sometime.

GWE

Been doing it for years with copper clad carbon arc electrodes and an ArcAir holder. Compressed air goes through the electrode holder and blows the kerf away from the cutting area. Find yourself a supplier of the carbon electrodes and a good used ArcAir and you're cutting. Not as pretty as plasma or oxy/acetyl but serves the purpose quite well.

That's interesting. Can I do that with a 200 amp DC welder?

i

Yes. I use DC (electrode positive) for steel and stainless steel. AC is supposed to be better for cast iron, copper and nickel but I only use DC on steel. My power source is constant current; I've not tried it anything else. We're talking lots of amps....I use over 250 on 1/4" electrode. You can use the 200 amp but I would look for 1/4" or smaller electrodes. Be safe! That compressed air will be blowing molten metal everywhere. Definitely not an operation in an enclosed area or in any place that has flammable material. Observe all the normal safety procedures for welding. Site below offers some info:

Best Regards, Keith Marshall snipped-for-privacy@progressivelogic.com

"I'm not grown up enough to be so old!"

Keith, that's very interesting. How does this torch blow air? Is the operator supposed to hold an air blow gun near the arc, os ir air supply integrated with the torch? Does it blow through electrode? Thanks

i

(removes

Works great for scrapping stuff, and kind of fun, too : )

I always thought that scarfing and gouging were the same thing as each other but referred to notching steel or cutting out defective welds.

But, as to cutt> I am curious if it is possible to cut steel using an arc welder and,

It will be interesting to see how much that outfit goes for. There must be over twenty dollars worth of electrode there. One can gouge anything that conducts electricity. They are ideal for cutting off alloy cutting edges that will not cut with a torch. There is nothing that will match it when you have to gouge out a weld defect. The bad part about it is the noise. If you screw up a weld and have to take it out everyone in the shop knows about it. You are sure to get some good natured ribbing at coffee time. :')) Randy

Best Regards, Keith Marshall snipped-for-privacy@progressivelogic.com

"I'm not grown up enough to be so old!"

I've never used one but I believe it blows air along the outside of the rod through ports in the rod holder/torch.

Best Regards, Keith Marshall snipped-for-privacy@progressivelogic.com

"I'm not grown up enough to be so old!"

Scarfing guns have air connects and electrical connects both. In the shipyards they routinely scarfed using 500A. A cut made this way looks very rough, like a series of 1/2" craters randomly overlapping in a line. I've never seen anyone who can really control an arc that strong and get a clean cut. It's mostly for severing metal or for scooping out metal. The sparks that come off these guns can fly 50 feet and be giant globules of molten steel, they are *much* more dangerous than torch sparks or welding sparks. These would easily set an asphalt street on fire, for example. Not very safe for a home shop.

GWE

Keith Marshall wrote:

Very nice. I think that using such a torch would be real fun for a short while. I may try to look for a cheap one that I could use to, say, prepare bevels before welding larger pieces.

i

I suppose that Gunner could try gouging at 500A with his CyberTig.

I wonder just what these people are wearing when they gouge metal with

500A of current. That is about 15 kW of power, all concentrated in one spot. Scary stuff. i

No, it doesn't matter much what you're wearing, except a welding hood and gloves and standard protective gear, of course. You do it so the air blows the sparks away from you. They really fly when air propelled. It's very spectacular when you see them scarfing on a structure up high at night, quite a bit like fireworks.

The *really* scary thing is an oxygen lance. One guy heats up a spot on something with a regular torch, then another guy has high pressure oxygen and the output is basically about a 4 foot steel pipe, and he just turns on the oxygen and aims it at the hot spot, and oh my how the metal burns out of there. The steel pipe burns too, of course, but more slowly, being cooled by the gas. They say that can cut dang near anything. Those sparks are much less controlled.

I've never even experienced thermit welding. That must be pretty exciting too.

Then there's explosion forming, jeez all these fun things.

GWE

Very interesting.

I have a can of termite, it is highly impressive how much heat it generates.

i

The more easily achieved and home-shop friendly (and cheap, and a pretty clean cut) method as discussed on this group a while ago is to dunk some

6010 in water briefly and crank it up to about double weld amps for whatever size rod it is. With a bit of practice, results similar to oxy-acteylene cutting can be managed.

I would like to caution people about using these arc air gouges. They require a very robust welding machine that can take high loads. Although I have gouged with 250 amp machines for only inches at a time, one should have

400 amps at 100 percent duty cycle available. Many larger shops restrict the use of the gouge to machines over 600 amp ratings. Gouging is much like putting a dead short across the leads of the machine and is very hard on the transformer. You also need large quantities of high pressure air. Randy

Very nice. I think that using such a torch would be real fun for a short while. I may try to look for a cheap one that I could use to, say, prepare bevels before welding larger pieces.

i

I would say using 6010 is definitely going to be easier on your 200 amp welder than an air/arc gouge.

As others have said, soak the rod in water. This helps to keep the rod from burning up as quickly, since you'll be running higher than normal amps for the size of rod. I have wondered if the moisture also contribute to a more vigorous arc ... ?

I have found the best results when cutting vertically down, with the arc pointing *into* the cut -- in other words, tilt the rod in a "push" direction rather than than the "drag" direction normally used with stick. The reason is that if you drag, you blow out the metal (that is your goal, after all :) and lose the arc, so you're constantly re-starting. But if you point into the cut, you're always facing into new metal. At least that was my experience as I played around with this. The cut edge is ragged, but much better than I would have expected.

This method does not produce the kind of far-flying sparks that arc gouging does, but it does produce a whole lot more sparks than normal welding. Take appropriate precautions! And of course, you do not want to be cutting directly on top of your welding table, unless you want to cut it too! :)

Andy