800 amp rated stick welders

One needs at least 400 amps at 100 percent duty cycle to arc air gouge with carbon rods. Welding shops that do heavy equipment repairs need such power supplies. Often 1000 amp constant current machines in shops are used for gouging. I have used gouging rods that were half inch in diameter. Wire feed semiautomatic processes are usually constant voltage however submerged arc welding can use D.C. constant current or even alternating current. I have seen over 900 amps run through a 5/32 inch diameter wire doing submerged arc. It is rare now that any money can be made welding with large diameter welding rods. Wire feed is the profitable way to go. Randy

When I was in the oilfield, a lot of jacket fab was going on at shipyards. A jacket looks like a windmill or high tension tower, A-shaped but is made laying on its side. It is made out of large diameter pipe. They used very large rods on them, I don't know the diameter. They were like 1.5 to 2x the length of average rod, too. The stubs were big as cigars. Maybe some of those.

I'll have to listen for more informed answers.

Steve

- Ignoramus27804 - wrote in news:pd-dnWqOr_eECIzanZ2dnUVZ snipped-for-privacy@giganews.com:

A friend worked in a steel mill, for a short time, and a good while ago.

He was doing things with rod, 30-some inches long. I don't recall, I'm sure the rods were 1/2 inch or larger.

Any of the 'Jet' rods (high deposit rates) from Lincoln want around 350 to 400 amps in the 1/4" size. They lay down beautiful beads but the puddle is just one runny mess so downhand only. This is pretty much the turf of wire feed or submerged arc these days. These rods have a lot of metal in the coating, the arc just melts that along with the core rod.

As others mentioned, arc gouging is the other high amperage area.

One thing to look at in the amperage ratings is the 100% duty cycle rating. Arc gouging can run close to 100% duty cycle, downhand on a long seam can easily get over 80% to 85%. That might knock the 800 amps down considerably.

Runn> I visited Miller website just to drool and looked at the stick welding

Ditto what Zimmerman said. I work at the mines and we have plenty of machines this size. A 500 is a standard size, but not really quite enough to drive any big loads like gouging. We dont have any machines smaller than 500's around. 800's and

1000's are in abundance and they are more the way to go. Some stick welding goes up to about 400A, but we dont do so much of that. Mostly these units are used to drive arc air gouging where the 800-1000A really helps. You can drive the 1/2" carbons pretty easy with these, and the harder to drive flat carbons. These units are also used to drive the sub arc tractors and a 1000 is about what you want for that.

Shaun

I have not run flat carbons in years. They are very versatile having a cross section much like a carpenters pencil. You can trough out a wide groove or turn them a bit and push out a narrow groove. For people who have not done arc gouging I liken it to pushing a blunt pencil along the surface of a block of butter. The air blows away the bulldozed refuse and leaves you a nice rounded channel. It is important to ensure you don't leave any bits of carbon down in there to contaminate the weld. Shawn is right... that even 500 is barely enough:') The bigger the machine the better. Imagine a repair to a huge bucket that goes on for weeks 24-7..... Then another one comes in for repair. Randy

"Shaun Van Poecke" wrote in message news:DEzQi.784$ snipped-for-privacy@news-server.bigpond.net.au...

Check out

They used to make some pretty large electrodes.

800amps wouldn't come near what they need.

I want to thank everyone. Looks like these capacities are mostly so that these welders can be used for submerged arc welding, or gouging, but not as much for stick. Very interesting.

i

So why exactly are you two doing all this gouging? Is it mostly to repair cracks? So you gouge out the cracks and fill it in with weld? Or are there other uses for it? Is it used for general cutting instead of other options like oxy or plasma?

I've played with air-arc a little bit at school to burn off backing strips. I was using a machine in the 400 amp range turned all the way up. Your description of pushing a pencil through butter is spot on. I can also understand why you would want much larger machines than 400 amps when working on thicker metal.

Working in a naval shipyard, we use these machines all the time to backgouge for full-penny welds. Crack repairs can often require a heavy duty machine.

Or, Lord forbid, some idiot puts the wrong wire into a submarine hull cut. Or they try welding a SubSafe hatch by laying unburned sticks of

11018-M in the bottom of the groove!

I've seen both of the above happen, and I have had to gouge out other people's F*&k-U%$ before.

Just thank GOD that all Pressure Hull work gets MT, UT, and or RT tested!!

TinLizzie

The flats are a bit more expensive than the rounds and harder to drive but very nice to use. I like them for clean up work when there is just too much weld left, say, when oxy cutting off a piece of 2" plate from another piece of 2" plate and there is a 1" fillet, you can use the flat gouging rods to give you very minimal clean up time with a grinder afterwards.

They also have 'slotted' carbons where there is a slot in one end of the rod, and a nub on the other end. As the rod becomes too short to be of use, you put a fresh rod in and attach the stub to the end of it, meaning you never waste any rod (or have to clean up stubs!).

Shaun

Back in the 60's there were some commercial power station reactor vessels that the welders had done the "lay extra rod in the groove".

Found it during the Gamma ray exams. Some of the welders were really whizzed about being caught and having to grind it all out and do it right the second time.

Hugh