Welding with a carbon arc, and silicon bronze filler rod

[lilranch2001]

Back in my industrial welding days, we used to do a lot of carbon arc, and 1/8 inch silicon bronze filler rod.

I am getting ready to set myself up for re teaching myself to do it again if......

Will my PA-300 let me weld it?

I totally forget the set-up on it, it seems like it was AC straight, but I am not sure

I am going to try to source the silicon bronze and carbons for it tomorrow, any advise would be appreciated, 30 years ago was a LONG time ago

I found this on the internet, we never used that type of carbon holder, we just put a carbon in the stinger
Carbon Arc Welding (CAW) | Welding TIG | MIG Welding | ARC

 

[Arc weld]

There is no polarity on AC. All the carbon arc torches I've seen were for AC machines but you could do a check on the internet if it will work on DC.

 

[lilranch2001]

The chart on my link says DC electrode negative, so when I find the carbons I am gonna try that

We used to use this on galvanized a lot, and it worked really well and was fairly strong.

One of my neighbors is interested in it as well, it has some good uses for thin sheet metal.

 

[k0ua]

Couple of things. If you do this make sure you have a good breeze outside. A carbon arc torch makes a lot of various carbon compounds, some of which probably are not good for you to breath. And make sure you are well covered up, those things make a lot more UV light than ordinary welding, so a "sunburn" is a sure thing.

 

[Reverser]

I think you may be talking about a twin carbon arc torch. I used one a lot back about 40 to 50 years ago.
Younger people now-a-days know only of the carbon arc torch used for gouging.

It's too bad that its kind of gone the way of the dinosaur. They were very handy and many times replaced the acet/oxy torch for heating and beating iron into shape. And, as you mentioned could be used for brazing.

As for using it on your PA-300, I've heard they will work on DC, although one of the carbons will burn down faster than the other. The carbons will burn down evenly on AC.
I wouldn't try it on my inverter, though, because I don't know if an inverter could take the punishment.

I could be wrong but it seems to me that carbon arc is kind of a dead short, and I question if an inverter could take the punishment like a transformer based welder could. That's one reason I've kept my Thunderbolt 225AC around, just for the purpose of using the twin carbon arc.

 

[yomax4]

If the PA-300 is really a 300, say 50-60% duty cycle it should work for the twin carbon torch. Just take it easy and don't run it beyond duty cycle. The torches were still available through Lincoln a few years ago. The carbons are the tricky part. If you use regular carbons like Becker or others, you will have to buy a box. If you use carbon arc gouge rods you can remove the copper coating and some LWS stores will sell you a few. Silicon Bronze is no problem to source. It's a weird way to heat and braze. I was surprised the 1st time I did it.

 

[oldpilgrim]

wow, that brings back memories. I used twin carbon back in the 60's before I could afford an oxy/acet setup.

Used it on my AC Lincoln buzz box. Carbon for brazing, sticks for welding. I did a lot of work with it.

Wouldn't want to have to use it now.

 

[Big Barn]

wow, that brings back memories. I used twin carbon back in the 60's before I could afford an oxy/acet setup. Used it on my AC Lincoln buzz box. Carbon for brazing, sticks for welding. I did a lot of work with it. Wouldn't want to have to use it now.

Haha. Same here. Used mine with an AC Forney buzz box. No welding with it but lots of brazing and heating. Don't miss using it, but I wish I hadn't thrown it out. Terry

 

[Relic]

I did a lot of brazing galvanized ductwork back in the day working in a Sheet Metal Shop.This method worked very well,then the shop went to using Mig.

 

[lilranch2001]

OK, so at 9 PM tonight I finally found time to try it

Electrode neg, 25 amps, sharpened carbon in the PA-300 stinger, and a scrap piece of angle on a scrap of galvanized

The first one was real sloppy, the second one I got a little better
I hope the pics attached, I do not put many pictures on this site