Carbon arc

[cobminor]

I am not sure where this should go so here it is.

I can remember some years ago a friend using a carbon arc brazing attachment on an arc welder. The thing produced a flame from two carbon rods. I have no Oxy-Acetylene and sometimes miss it. Have any of you got any experience with this stuff, or do you know if you can still get it? Thanks.

 

[weldequip]

Not sure if the attatchments are still available or not. They are crude but do work. You have two consumable Carbon rods than when pushed together produce a 'flame', to then use with any standard brazing rods.
Somwhere like Frost auto restoration might still do them.
weldequip

 

[bill_gj]

I got one of those attachments with an arc welder I bought about 25 years ago.
It works very well for heating things up in general and you can indeed braze quite well on thick-ish stuff.
Brazing anything less than about 2mm always ended up with some distortion as the heat input from the 'flame' is over quite a large area compared to, say, a BOC Sapphire torch.

You can find the carbons on ebay.

 

[shenion]

I see them come up one ebay.

I think the rods want over 200A.

 

[classic2cv]

i've got on of those Carbon arc things in the shed

you used it with an acr welder

it worked ok a far as i can remember , not as clean as an Oxy-Acetylene set

but you can heat things and Braze with it

 

[Wozzaaah]

I've got one too, only bought it cos it looked like it might be useful. Tried it once, hung it up and it's still there

 

[irondarren]

no 25 nozzle, just the jobbie for brazing (roflmao), i have to admit to using a flame cutting head last week for a bit of brazing

 

[snowcat]

A word of warning chaps, A freind of mine is missing half his eye thanks to carbon arc, forgeting the flame was as intense as arc welding he used only gas gogles, You must use a full welding lid with it.

 

[SteveTheAngryWelder]

Thats not the only way to carbon arc weld. using a bronze filler its possible to braze with just a power source and a stick welding handle.

using a stick/tig power source, set up for tig, get your heat setting about 40 - 50 amps, sharpen a carbon rod and put it into your arc welding electrode handle with a comfortable working end sticking out, say about 2 inches.

lay the bronze rod where you are welding and strike the arc with the carbon THROUGH the bronze rod. striking the arc on the metal will make a mess and ruin the metal. stay overtop of the rod for the entire length of the weld using as short an arc as possible and melting the filler rod.

do not feed in more rod, 6 inches of rod equals 6 inches of weld.

do not dab the rod in and out, there is no "puddle" as such

the welding should be fairly silent or you have too much heat, a little bit of crackling is ok.

the carbon will dull down pretty quickly but dont resharpen, keep welding and it will sharpen itself to a nice point.

i use tig settings because they maintain a more stable arc, works well for sheet metal particularly galvanized. you can get as low as 20 ga. easily but can go thinner with practice.

 

[Philzick]

Bronze filler?

That bronze filler thing sounds interesting Steve. I'm about to resurrect an old arc welding machine I bought years ago. Don't know what it is as the paint has loing since fallen off!!! Yes I'm a beginner (as if you didn't know already) so the bronze rod you suggest using as a filler. Is just "bronze wire?" of a suitable thickness or something else? I'm guessing that the arc melts (a bit like soldering) the bronze into the joint. Is that the concept? I want to fix an old pick up... doesn't have to be pretty, just good (but light guage) steel over suspension tops and wheel arches for an mot. Light guage metal and arc welders don't appear to mix but this looks like a possible route to explore. Thank you in advance for your advice.

 

[Paul.]

That bronze filler thing sounds interesting Steve. I'm about to resurrect an old arc welding machine I bought years ago. Don't know what it is as the paint has loing since fallen off!!! Yes I'm a beginner (as if you didn't know already) so the bronze rod you suggest using as a filler. Is just "bronze wire?" of a suitable thickness or something else? I'm guessing that the arc melts (a bit like soldering) the bronze into the joint. Is that the concept? I want to fix an old pick up... doesn't have to be pretty, just good (but light guage) steel over suspension tops and wheel arches for an mot. Light guage metal and arc welders don't appear to mix but this looks like a possible route to explore. Thank you in advance for your advice.

Brazing and Bronze welding are not accepted by mot testers on structural repairs, you really need to get a mig set to do anything worthwhile on cars

 

[Philzick]

bronze thingy...

Thanks Paul, I'll try the 1.6mm rod with a copper heatsink behind it and see how I get on. Don't really want to invest in a MIG set-up (although I appreciate it would probably be easier) I've been quoted around £350 + by a local welder to fix it but in all honesty the pick-up is only worth that much so I'll have a go and see how many holes I can blow in it!!!