Dual Carbon Arcs

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Hi everyone.  I have an old Sears stick welder that also can be used as a dual carbon arc , torch I guess.  I don't have a manual for this welder.  I have played around with the dual carbon arc thingy, and made some sparks but I don't really know what I am to use it for.Do I sharped the carbon rods?What do I use a dual carbon arc torch for?Is there other ways to use this carbon arc for.  As in using only one carbon rod for heating or brazing?I didn't try but can I arc using only one carbon rod or do I need to use both?Thanks in advance for your help.
Reply:Because I'm naturally lazy, I just hauled some information in for ya.The carbon arc torch is primarly used for heating metal for bending or strightening, brazing, and heatingl for hard surfacing compounds to be applied. I have not seen one in the welding supply stores or web-sites in a long time and I don't think they are manufactured any longer but I could be wrong. The good news is that the carbons are still available. They are the same as the carbons used for carbon arc gouging which is another process used to cut metal. These are still in use and being manufactured. The carbon arc tourch works by attaching the leads to the welder. Place one in the ground clamp and clip the other one in the rod holder. Set your welder at it's lowest setting AC or DC. ( either lead can go in either clamp, no right or wrong way ) I should have said to load the torch with the carbons before attaching it to the welder. You didn't say if you have any carbons. If not they are about six inches long have a carbon center covered by a copper outter shell. Place the carbons in the torch so they are sticking past the holder about three inches.( you may have to adjust the length longer so you don't melt your torch) With the torch unhooked from the welder practice moving the carbons together so they just touch then move them apart about an eighth of an inch this will strike the torch and the carbons will start to burn. ( when the torch is attached to the welder ) You must wear your helmet just as if you are acr welding. After striking the torch with your helmet on place the burning end close to the metal you want to heat up, about an inch away, you will see the metal start to sweat and turn red. Don't touch the torch to the metal or it will pock mark it. The torch kind of sizzles when it is burning. The carbons burn very slowly and cost 1.50 to 2.00 the last time I checked. They come in several sizes 1/4, 3/8, and larger. This is much cheaper than running a OA torch set up for heating metal. If you have a Tractor Supply Store near by or another farm store or welding supplier you may be able to pick up a Forney Welding Manual. It has several chapters on using the carbon arc torch. A web site that has info is www.aussieweld .com. This is a Australian site but the information is very good. My personal opinion of those arc torches is that they are good for 2 things, hanging on the wall, and loosening rusty nuts.  They are way too hot for brazing, and tend to burn the crap out of anything you use them to heat.   For loosening nuts and sometimes pullys, just hold the carbons on opposite sides of the hut, and switch the machine on at around 76 to 100 amps and let her cook a while.  This can be hard on a machine so watch your duty cycle.Single carbon arc on AC ain't worth spit.Appreciation Gains You Recognition-
Reply:Slagking:I wrote the post Franz hauled in. I like my torch because it is so easy to hook up. The heat is instant and it is very cheep to run. The carbons are much less expensive than I was quoted by my local supplier, about $18.00 per 100 carbons for 3/16 size. When using the torch be careful not to get it to close or it will burn up the metal. An odd thing about it is, the farther apart the carbons the hotter the flame. Try and find a Forney welding manual at a Tractor Supply Store. I think there are 3 chapters on using it, everything from heating frozen nuts like Franz mentioned to brazing. It is an old process but if you don't have a OA set up to heat metal for strightening or bending the double carbon arc torch will be your friend in a pinch! One more thing the flame is actually brighter than arc welding so don't forget the helmet. If you were using it a lot or for an extend time you might want a darker lens. Happy heating!
Reply:Thanks guys.  I havn't used it much but I think since things are a little bit slower, because of the snow and all, I'll go play with it and learn how to use it.  It was a freebie from a friend that bought a Miller Stick welder.  He doesn't know how to weld anyway.  I have a nice Smith MC torch set and use it everyday, mostly to keep me warm.  Thanks for the tips and I'll let you know how I'm doing with the carbons.  Oh yeah, I have carbons already, thanks.
Reply:Back in the 70's when I was in Uncle Sam's canoe club (AKA navy)I lived in base housing in Navoto Ca, North of S.F.. I had a 235 amp Craftsman buzzbox, that I plugged into the house dryer outlet. I wanted to be able to heat and braze. Th NAvy Housing people frowned on having an oxygen/acetylene outfit in housing. I bought a carbon arc outfit from Montgomery Wards In MillValley Ca.I was not too successful with it. Couldn't see the puddle very good for brazing. As fer heating, it's difficult to see color changes on the material. I was much more successful taking jobs onboard ship and using the torch in the machine shop.
Reply:Hi, I built a carbon arc torch in hopes of brazing with it, but I seem to be unable to transer heat to the work piece without melting it.  I was wondering if anyone could provide me with tips.  I made my torch such that I could both pivot and slide back and forth one electrode, not really knowing what the best way to set the thing up would be.  Also I have quite a few degrees of freedom in my torch setup, so I should like to know any thoughts on the most effective orientations of the carbon rods.  I can't quite make out what it says on the picture of the box posted.  I should like to know are there many limitations on what can be brazed with the torch and an 130 amp dc machine, and what sort of thing would be easiest to try out in order to get the hang of the process.  Would I be better off sticking one of my d-cells in a stinger and setting current low?  also, appropriate current settings would be helpful.  any suggestions would be appreciatedThanks,corneliushere is an image of my toy: http://www.glue.umd.edu/~neilg/pictu...0cam%20040.jpg
Reply:There is an almost parallel thread to this one in the "Lincoln" forum below that may be of interest to readers here.  I posted a couple of comments there describing what I consider to be very successful uses of a single carbon for specialized tasks for which I don't think I could have as successfully used conventional welding torches, O/A, propane, MAPP, arc or TIG.As I commented there, part of the difficulty in using the carbon arc for many tasks is the excessive heating resulting from inability to reduce current/voltage to low enough values with most welding power supplies.  I have been using a very old 880 watt transformer with a single carbon holder sold under the name, "General Electric PYROTIP Electric Burner," that I picked up at a garage sale for about $3.  The transformer is very small compared to anything sold as a welder (laminated core 6-7/8" x 5-1/2" x 1-1/4"), but I still get excessive heating and melting of the work unless I time everything perfectly.  Open circuit voltage is 8.2 volts, which implies maximum current of about 110 amps and probably lower actual current due to contact and carbon resistance (the stubby, fat carbon does not have a copper sheath).  I hope to improve control of the temperature by providing either a low value, high current resistor in series with the carbon holder or a variable transformer controlling the voltage at the transformer primary winding.So I can't agree with Franz's statement, "Single carbon arc on AC ain't worth spit."  It all depends on what task you are trying to accomplish and how you handle the equipment.awright
Reply:well, for what it's worth, my machine claims it can do as low as 5 amps.  ON an ac circuit you could try adding a series inductor in your circuit and benefit from the impedance of and inductor (2*pi*f*L), and you could make it variable by sliding some core material through the center of your coil.  This could be cheaper than a high current resistor, but I don't know.also, I was thinking of replacing the carbon in mine with tantalum.  Has anyone heard of that?  we have some scraps laying around, and I thought they were stainless till I tried to weld them.  It apparently has a very high melting point.Last edited by corneliused; 05-04-2006 at 08:31 AM.
Reply:Well, corneliused, with down to 5 amp settability, it sounds like you may be well equipped to use the carbon in the contact mode I described in the other thread.   That is, if you have a need for it.  It is certainly not a general-purpose tool.  I have not tried using carbons in the arc mode between two carbons because I have not yet had the need for that type of radiant heating of a workpiece that a gas torch couldn't handle.Speaking from intuition, not experience, I would guess that using a two-carbon arc for radiant heating of a workpiece is much less controllable and versatile and more contaminating than using a gas torch for the same task.  However, I have been very satisfied using the carbon for specialized tasks in the single-carbon contact mode.awright
Reply:http://www.mylincolnelectric.com/Cat...et.asp?p=20690The above is a link to the Liincoln Carbon Arc Torch. I've had one for years. They are great for brazing and very inexpensive to run. You can power one with your stick welder or any small "buzz box". Looks like $82.86 list. Airgas carries them in stock according to their website.
Reply:Originally Posted by corneliusedHi, I built a carbon arc torch in hopes of brazing with it, but I seem to be unable to transer heat to the work piece without melting it.  I was wondering if anyone could provide me with tips.  I made my torch such that I could both pivot and slide back and forth one electrode, not really knowing what the best way to set the thing up would be.  Also I have quite a few degrees of freedom in my torch setup, so I should like to know any thoughts on the most effective orientations of the carbon rods.  I can't quite make out what it says on the picture of the box posted.  I should like to know are there many limitations on what can be brazed with the torch and an 130 amp dc machine, and what sort of thing would be easiest to try out in order to get the hang of the process.  Would I be better off sticking one of my d-cells in a stinger and setting current low?  also, appropriate current settings would be helpful.  any suggestions would be appreciatedThanks,corneliushere is an image of my toy: http://www.glue.umd.edu/~neilg/pictu...0cam%20040.jpg