carbon arc welding

[Seattle Smitty]

New here (howdy, howdy).

I'm on a couple of Stateside sites that are talking about the two old welding processes of single-carbon and twin-carbon arc welding/brazing/heating. These have long gone out of fashion in the States, not many people have the special torches and fewer yet know how to use them. Young welders have never seen the processes, and confuse them with arc-air gouging, a very widespread modern technique which uses a carbon but otherwise is unrelated. We are not sure whether anyone still manufactures the welding/brazing torches or the special carbons, which were available in a range of sizes.

Carbon arc may be out of fashion here, but that doesn't mean that it is without utility, and in fact I occasionally use my twin-carbon torch even though I have all the modern gear. I am wondering if these supposedly "obsolete" processes maybe thriving in other parts of the world. Is carbon arc still taught in the UK, and is new equipment available? The carbons are/were different from arc-air carbons, were about 6" long and came in diameters from 3/16" to 1/2." I know carbon arc still has a few very specialized, automated applications in industry, but I'm interested in the old manual versions. I saw one reference with a lot of Cyrillic printing, suggesting the the Russians and E. Europeans may still use carbon arc. Anybody know about Western Europe?

 

[GeorgeB]

Carbon arc may be out of fashion here, but that doesn't mean that it is without utility

I agree. It interests me too, as does any simple, lower cost process which is 90% as good as some other process at much higher cost. I think someone here once said there was no such thing as carbon arc welding. "Wrong!" I thought. I'm not sure it's used anywhere commercially, though and I would understand that. But, for non-critical home use, that's why I'm interested. I've had some limited success but need to spend more time developing my technique. Does anyone else here use a single carbon arc rod for welding (not braising)?

 

[GrahamGKD]

Ah yes, I remember those. I have a torch in a drawer which I haven’t used for maybe 10, maybe even 20 years. My recollection is a lot of heat but not that easy to use e.g. for brazing, difficult to 'focus' the heat. I believe the carbon rods have some kind of copper sheath. If anyone in the UK is interested in having a play they could have my bits for the cost of the postage (or collect from Bournemouth for free). I'd have to dig it out but I believe I have the torch and a selection of carbon rods.

Graham.

 

[bonepyro]

I had one of these sets to attach to a little clarke arc welder. Probably about 20 yrs ago now (god that makes me feel old saying that).

Basically one fixed carbon, and one on a slide. You had to push the moving one forward to make contact with the static one, and then back it off to create and maintain the arc.

I remember it would generate immense heat, and of course light. I remember using it for brazing up the exhaust on a bike I had when I was 16 or 17. I never used it for welding, but would imagine it would be very difficult to get the heat into the work in any controlled manner to actually manage a weld.

I am sure it came from machine mart or the equivalent back then. Sold as an accessory for the old transformer arc welders.

 

[weldone]

single I thought you needed 2 rods what would the fill metal be in.

 

[Paul.]

We've discussed carbon arc welding a few times on here, try these links
here, here, and here,

 

[Seattle Smitty]

Good photos of some of the equipment (there was a lot of variety in the handpieces for these processes) on your first reference, second page, Paul. But it appears from all of your answers that carbon arc, single or twin, is as out of fashion in the UK as it is in the States.

If you have or acquire an old twin-carbon torch to fool with, experiment not only with various diameter carbons (if you can get them) and amperages (you can find tables of recommended settings), and gaps (which alter the "flame" shape), but also the relative angle of the two carbons (also alters flame shape). Twin-carbon work is best done with AC, otherwise the electrodes are consumed at different rates.

If you have an arc-air gouging rig, you can try using the single carbon as a handy heat source for light bending, or even try welding with it. You can use an arc-air carbon in a stick-welding torch, but be careful not to overheat the torch. The carbons get hotter than stick electrodes, and some purpose-built single-carbon handpieces in the old days were water-cooled.

You'll probably see that I've replied to a couple of the other old carbon-arc threads here, and some of what I offered there is redundant. I guess I'd like to see some modern interest among the curious in the real, if occasional, utility of single and twin-carbon arc. It's another tool in the kit, not essential, but no joke either.

I'm going to see what I find in other parts of the world, and will inform you of anything interesting.

 

[GeorgeB]

My interest is primarily in welding, rather than braising with carbon arc. Wikipedia even has a separate heading/'subject on carbon arc welding.

"Carbon Arc Welding (CAW) is a process which produces coalescence of metals by heating them with an arc between a nonconsumable carbon (graphite) electrode and the work-piece."

That's what I tried and it worked. I'll try and find my sample piece of metal and will post a photo.

 

[Seattle Smitty]

By Googling "twin-carbon arc torch" I found several discussions, some with photos. If you want to see what some of the old torches looked like (and there was a lot of variety), you might try that.

Then I tried a site called WikiAnswers. Some guy had submitted a one-sentence article that was misspelled, ungrammatical, and factually wrong! So I edited that out and composed an article of my own. Presto, I'm an author. This is going to my head, and I'm now reading other such offerings with a critical eye; I think my article beats the one in Wikipedia all to bits http://wiki.answers.com/Q/What_is_Carbon_arc_welding

Meanwhile, I have located a firm on the U.S. east coast called Cinema Carbons, which makes (or just sells?) a range of carbons for the remaining movies theaters using the old carbon arc projection equipment, and possibly also for the old stage spotlights. I haven't been able to talk to them yet.

 

[Mikey98118]

New here (howdy, howdy).

I'm on a couple of Stateside sites that are talking about the two old welding processes of single-carbon and twin-carbon arc welding/brazing/heating. These have long gone out of fashion in the States, not many people have the special torches and fewer yet know how to use them. Young welders have never seen the processes, and confuse them with arc-air gouging, a very widespread modern technique which uses a carbon but otherwise is unrelated. We are not sure whether anyone still manufactures the welding/brazing torches or the special carbons, which were available in a range of sizes.

Carbon arc may be out of fashion here, but that doesn't mean that it is without utility, and in fact I occasionally use my twin-carbon torch even though I have all the modern gear. I am wondering if these supposedly "obsolete" processes maybe thriving in other parts of the world. Is carbon arc still taught in the UK, and is new equipment available? The carbons are/were different from arc-air carbons, were about 6" long and came in diameters from 3/16" to 1/2." I know carbon arc still has a few very specialized, automated applications in industry, but I'm interested in the old manual versions. I saw one reference with a lot of Cyrillic printing, suggesting the the Russians and E. Europeans may still use carbon arc. Anybody know about Western Europe?

This is quite unlikely, mainly because brazing has been a much more popular and sophisticated process, as practiced in the UK, than it ever was in the US. You can still find special brazing equipment being built, and the process taught in English schools. By process, I mean torch work backed up with special chip forges for simultainious secondary heating of the work piece.

During the 1950's, when Twin carbon-arc was at the peak of its popularity here, brazing hit its peak in the UK. The brazing process is dimminishing there today, in no small part because of the switch from butane to LPG.
You see, butane is only rated a little hotter (100 degrees F) than propane burning in air, but a butane flame puts out about one-fifth more heat than propane becuase it needs far less oxygen, and therefore, much less useless air content gets processed. Needless to say that butane is a much better fuel candidate for oxygen enrichment than propane, which is an oxygen hog.

Unfortunately, LPG (commonly 80% propane to 20% butane) is more convenient for most people to deal with in cold climates. Needs of the marketplace trump technically superior products just about every time.

 

[dognose]

Carbon Arc Brazing in GB

Hello - This is my first post with the forum. I recently bought an Oxford 110b which came with a double carbon arc torch and also a single one. I'm building a recumbent trike and wanted some way to fix it together. started practicing with the welding electrodes and although my results weren't good I found it much easier and smoother than the SIP buss-box I had years ago. Then tried brazing with the double carbon torch, my previous experience being silver soldering with propane gas. The flame is much hotter but also more localised than with propane. This means you have to be more careful and watch closer but it does let you braze, a bit at a time, much larger jobs than would be possible with the propane torch. Still need a lot more practice but I'm pretty impressed with the carbon arc torch. Haven't tried the single carbon torch yet but, having read another post on this forum, I now have an idea of the technique required and will try it soon. I have only found one supplier of the double carbon torch (on ebay, around £30). There are a few ebay suppliers for the carbon rods. I have tried two of these and found that there is variation in how the rods from different suppliers work. You may have gathered that (smug git) I'm happy with both the welder and the carbon torch. I don't really know what the state of this black art is in GB, so the title is a lie really - oh well.

 

[norlander]

can't give a technical contribution but I do remember buying a single carbon arc torch some years ago (ok-many years ago) which was supposed to work off a car battery-it was rubbish of course, I got it from the Exchange and Mart publication.
As Mikey 98118 has mentoined, I recall our school metalworking shop having a brazing hearth-there was (I think) an air/propane torch-you laid the workpiece against the coke in the hearth.
I seem to recall that the idea of the carbon arc process was that it needed no gas and also that an arc welding transformer could be used on thinner materials using carbon arc???.

 

[theveryman]

Remember years ago when I was an apprentice Sheet Metal Worker Just when north sea gas was coming to the fore,we were making adapters for existing gas fires so they could burn natural gas,we used single a single plain carbon rod with a bronze filler rod to braze the seams of the zintec adapters we made up

 

[mike 109444]

Welcome Dognose. Like many other I have one of the carbon torches lurking in the shed also there was the "spot welder" type that used a single carbon. MM still sell the carbons! I hope you are using a Welding mask when using the torch because the arc generated will give you sever sunburn if you are not protecting you skin and the green filter in brazing goggles won't protect your eyes.
I did try welding with mine many years ago but was on a car and as weld cooled it would crack. When speaking to a work college about this he seamed to think it might be due to the carbon being introduced into the weld causing it to become hardened and thus fracturing. Did dig it out a while back bought some carbons in case I needed to heat (and maybe harden?) any metal but not needed to todate.