# carbon arc questions



## SE18 (Sep 27, 2013)

My uncle in upstate NY has been using a carbon arc attachment on his stick welder for a few decades to heat metal. I didn't get a chance to see it but was curious about it. I've got oxyacy but the gas is really expensive so I'm looking into something lower cost to heat metal. Maybe this.

Where do you get these? Are they really worth it?

Can they also make holes in steel?

Do the twin carbon sticks need replacing?

Thanks (I'm using a marquette WW-2 era stick welder)


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## Old Iron (Sep 27, 2013)

You mite google it I don't think they make them any more But I could be wrong. The rods wear down and need replacing. I have brazes and heated metal to bend but never a whole. If you get one besure and wear a welding hood unless you want a good sun burn. Ask me how I know.

Hers one on ebay.  http://www.ebay.com/itm/Carbon-Arc-...faultDomain_0&hash=item27d88f5663#ht_25wt_917

Plans to build one.  http://www.instructables.com/id/Make-a-carbon-arc-torch-for-your-220-volt-stick-we/

Paul


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## Tony Wells (Sep 27, 2013)

We had a nice thread a while back discussing their use. You might want to search for it and have a read. Of course, electricity isn't cheap, but it may be cheaper than gas where you are. I'm not really seeing anything drastic here on gas prices.


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## Ulma Doctor (Sep 27, 2013)

Hi SE18,
i had a thread a while back that may be of assistance, click the link below, i hope the info helps out!

http://www.hobby-machinist.com/showthread.php/15015-Twin-Carbon-Arc-Torch


mike)


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## SE18 (Sep 28, 2013)

thanks for the resources. They don't look too hard to make. Would o/a goggles be ok or does it need to be a helmet


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## Tony Wells (Sep 28, 2013)

ABSOLUTELY NO GOGGLES! A hood is necessary. The arc is at least as strong as any other form or electric arc welding, perhaps more intense. Long sleeves, button up collar, etc. It is too easy to get a bad burn with an arc torch.


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## shovel80 (Sep 28, 2013)

The only Carbon Arc I've ever used was for blasting away cast iron making a "V" in order to weld broken castings back together.....Talk about Noisy and Hot!!

Terry


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## SE18 (Sep 28, 2013)

so most replies thus far use the device for cast iron I see, brazing model. Guess the "wide" flame/heat contributes to heating up the rest of the casting so the issue of heat in just a small area while cold in the other obviates the worries about causing structural fracturing (the molecular strength of the steel's internal geometry). With normal oxyacy, the method is usually to heat up the cast iron part in an oven or just with acy and then proceeding to the brazing.

Anyway, I did bid up to $20 for the ebay one. If I don't get it I'll order some carbon rods and build my own.

on the older link supplied, there's old instructions for its using, indicating that carbon rod size fits the job at hand so looks like it's handy to have different size rods.


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## Old Iron (Sep 28, 2013)

The torch terry is talking about looks like this.
	

		
			
		

		
	



	

		
			
		

		
	
 I have one but I haven't used it is years. If you good enough you can shave a weld off two plates welded togather and just leave a little under cut.

Paul


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## Ulma Doctor (Sep 28, 2013)

the torch pictured by Old Iron is a gouging torch, it is not suitable for brazing or heating metal.


the twin carbon arc torch is used for heating, brazing, etc., it looks similar to this below:


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## SE18 (Sep 29, 2013)

I guess I've got a lot to learn now. Gouging torches too! All this time I never knew there were accessories for a stick welder. What a versitile machine!

Now I'll have to google gouging attachments to see what the heck they do; this stuff is addictive

If I did it for a liviing, however, I think the fun might dissappear so that's why I'm on "Hobby"-Machinist forum


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## epanzella (Sep 29, 2013)

I had a carbon arc torch for many years. Very hot and very awkward. It has limited use as you can't direct the heat to heat a specific spot without overheating everything around it. It won't replace an oxy-acetylene outfit. And, like other's have said, you need a full welding helmet and long sleeves or you'll peel like a lizard from the most intense sunburn you've ever gotten.


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## leadunderpressure (Oct 1, 2013)

With carbon arc gouging, can you cut thin sheet with that? Say 1/4 inch mild steel? Just how sloppy is the cut?


Sent from my iPad using Tapatalk HD


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## shovel80 (Oct 2, 2013)

We just used the carbon arc torch for scarfing cast iron away....it's sort of like using a Oxy-Acetelene torch, but I don't think it was as accurate....It uses compressed air instead of the Oxygen to blow away the molten metal...the oxy torch won't cut cast iron............Maybe a Plasma cutter would be the best today?

Terry


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## SE18 (Oct 2, 2013)

I just got outbid on the fleabay carbon arc so looks like I'll put making one on my list

got my oxyacy tanks refilled, nothing beats that!


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## sniggler (Oct 3, 2013)

I use a carbon arc gouging rig at work all the time for removing welds, beveling, scarfing ect... It is much faster than an oxy/acetylene torch for those things. It also doesn't have as much heat input to the base metal so it is preferred on structural steel. It is not used for welding or cutting although you could make a rough cut with it, it needs about 450 amps and constant use will pound a lighter duty cycle welding machine pretty fast.

I have not used the other type of carbon torch which looks like it would be fun to fool around with.

Bob


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## Dunc1 (Nov 24, 2013)

Popular Science Oct 1941 has instructions to build a torch (I have seen others on the internet) and a handy chart for amps vs rod diameter. I have not personally tried using the arc torch but I did use it a few times many years ago with the carbons in direct contact with metal to heat it up. Worked well. I no longer have the torch or any rods.

The Pop Sci chart recommends:
1/4" dia rod = 5-30 amps
5/16"          = 20-50
3/8"            = 40-80
1/2"            = 75-125


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## SE18 (Nov 25, 2013)

I posted this elsewhere in forum but I did end up building one:

https://www.youtube.com/watch?v=i85PCW-M8fc

I use 1/4" carbon rods at 85A with my marquette stick welder. The reason I used it to weld is that I ran out of O/A fuel so I just grabbed with carbon arc torch and kept going, not as good but it worked

I so far used it to remove welds, braze, remove paint
	

		
			
		

		
	





	

		
			
		

		
	
 and interestingly, I even used it to weld this spider together


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## SE18 (Dec 24, 2013)

Merry Christmas to everyone. I was out playing with my welding equipment and decide to experiment some more with CAW and CAG welding.

I managed to fusion weld two steel rods together (3/8" dia) in just a few seconds, quicker than my oxyacy

I also produced a bolt from allthread and a nut using CAW fusion (no filler)

Then I tried CAG welding, although it probably isn't really "gouging" per se. What I did was connect my Marquette stick welder common directly to the roof of this steam derrick you see and then the other common connected to just one lead of the carbon arc welder. Using this method, I was able to punch this hole in sheet metal. I also did some sheet metal cutting using this technique. 

OxyAcy seems to work better for me in doing these functions, but I'm thinking that with some practice, I can improve in carbon arc welding


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## Metalbender (Jan 4, 2014)

For those interested in the carbon arc torch, search Forney carbon arc.  I bought a new one many years ago, since I don't have an OA set. Works great for it's intended purpose, heating and brazing. Now having a plasma and the carbon, I haven't run across the need for a torch set.


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## ericc (Jan 5, 2014)

I made one of these for a homemade welder that had too little open circuit voltage for keeping an arc on a standard stick rod.  It did not work well, and it sat unused for years.

Recently, I had to set a fairly large tenon for a blacksmith project that contained a melted in bronze bearing in the other end.  A coal forge would have been fiddly, since the bearing would have been heated quite a bit while getting the tenon up to temperature.  So, the assembly was clamped in a post vice, and the protruding tenon heated with this carbon arc torch.  It did not work so well.  The bearing did not get burned, but the arc "flame" was too localized, and ended up singing the tenon in unattractive ways.  Eventually, this worked, but the job looked sloppy.  Fortunately, the tenon joint was not the only source of strength, since there were scrolls and collars to keep things snug.

The loud bright "flame" tends to make you rush and do silly things, especially if there is a hammer in your right hand, since the carbons are always getting shorter, and you are adjusting them.  It is not completely certain that they are cheaper than gas, especially if you use oxy-propane for heating.


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## SE18 (Jan 5, 2014)

While no expert myself, I've come to the conclusion that with practice and maybe innate skill, any welding process can be used but it's just as good as the user using it.


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