Anybody know about carbon arc brazing.

[nickjaxe]

Hi guys dug out a carbon arc torch I last used around 40 years ago....it still has 2 old carbons it...6mm.

I had a dabble with them hooked up to my very old Oxford 110amp oil filled arc welder.....it fired up right away with a nice flam....did some heating and a little braze to remind myself how it was.

Then the carbon were to short to do any more they were 6mm.

I was surprised I saw lots for sale on ebay...listed as carbon gouging rods/brazing rods.

Anyway ordered a pack of 8mm carbons....no idea why I ordered 8mm...suppose I thought maybe better....but the weren't..they were pants.....at 110amp it was not to easy to get an arc....it was unstable....I gave up......

Any ideas guys....is it a case that 8mm are to much for my 110amps or are these carbons not suitable.

I can get 6mm but am I wasting my time.

Only reason I want to use it is I dont have access to gas welding gear any more.

Nick in the UK.

 

[Kram]

I've heard they are not too great, never tried. 8mm will need more amps to light up.
I did buy some carbons however, Im told its a good way to ruin an inverter machine, so I havent tryed them with mine - its a l tig.

What are you intending to braze?

Propylene (mapp substitute) gas and silver solder may suit small items?
Or induction brazing?

 

[MattF]

I seem to recall asking about gouging rods on here a few year ago. Think the general opinion was that gouging rods are slightly different to brazing rods.

 

[Jack Ryan]

I have no experience at all with carbon arc but I would grind/sand a 20 degree point and then make a 6mm diameter flat on the end.

I suggest that because I think the current is too little for an 8mm rod.

Jack

 

[hunter27]

In the 70's we only had a cheap buzz box Topweld 140 (I think) and used to use it mainly for carbon arc brazing on cars mainly, it worked well apart from in tight spaces where the rods often got snapped. After a few years, new rods we bought were nowhere near as good and it was very difficult to get a stable flame, we noticed that the new rods were a lot duller copper than the old shiny ones and it was suggested that they may have been gouging rods. Moved on to MIG after that so we never got to the bottom of what had changed. Still have a a jar of old part used rods in the garage with a tin of SIF flux.
Happy days.

 

[Porkypine]

As in the post above, I used these in the early 80s with a crappy tin box arc set, and ditto the carbon rod brazing was its most useful function, it was crap for welding.
I found carbon arc brazing was quite good for what I was doing (I've also done a bit of O/A brazing for comparison ) if you've got the stuff give it a go, it's certainly another useful bit of kit in your arsenal IMHO.

 

[mike 109444]

Much as the two post above ref using just a buzz box back in the day. The 8mm ones would light ok.
You could try getting the carbon rods from machine mart as they use to still sale them (just had a quick look and can't see them on there site )
Might be worth looking at the "specs" of the gouging rods to see if they mention arc brazing or look up carbon arc lighting !. If you are not already aware you need a welding mask not goggles for using.
I seam to recall there was even a medical treatment using the light produced from these rod
If all the 6mm bit you still have are long enough you could make up some holders to fit them into. see pic.
When I was using one of these years ago to weld in some floor patches I was getting the welds crack just after finishing a run. Mentioned this to a work mate and he said that due to the carbon being introduced in to the weld pool the welds would be brittle and crack, so just be aware of that.
There was also a "spot welder version of the carbon arc that used just one carbon rod.

 

[mike 109444]

This has got me looking this up again (well ok Googling it )

Checked out the comments by "scooter Tramp"
Lead to this http://www.hobby-machinist.com/threads/twin-carbon-arc-torch.15015/

 

[Cobbler]

I think I’ve put this on before, but…..
A friend from work was fitting a sill many years ago with a carbon arc torch & after a while he had this feeling he was being watched. He looked up from what he was doing & saw loads of cats sat intently watching him sat on the wall. He had no idea whether it was the noise, smell, light to what attracted them, but they seemed fascinated by it. Cats with arc eye anyone? Try explaining that one to the vet!

 

[Porkypine]

I think I’ve put this on before, but…..
A friend from work was fitting a sill many years ago with a carbon arc torch & after a while he had this feeling he was being watched. He looked up from what he was doing & saw loads of cats sat intently watching him sat on the wall. He had no idea whether it was the noise, smell, light to what attracted them, but they seemed fascinated by it. Cats with arc eye anyone? Try explaining that one to the vet!

A place I do odd bits for has pigs near to where I'm often doing bits of welding, I always make sure to put up bits of board or whatever else is lying about to screen what I'm doing so they can't look at it... Coz I'm nice like that!

 

[brightspark]

i had a few sets given they can create a hell of a lot of heat but you cant localize it . pretty much rubbish unless you have nothing else like oxy acet or oxy propane . gave mine away to someone on here to experiment with

 

[jsf55]

I wonder if it's the frequency of the arc that attracts them? Had a set, did loads of brazing with my set which got borrowed by a mate who promptly set the inside of his car on fire along with them and the buzz box !

 

[nickjaxe]

The rods were advertised as gouging and carbon arc brazing.....dont suppose I will ever know....maybe different to each other.

As I said did quite a bit with them maybe 35 years ago....

Just want them for the odd brazing job.....also heating.....the were very good for that I seem to remember....for little money.

A pal has a Map Gas torch seem to be a slow job heating anything of size.

thanks for the input guys.

 

[Farside]

As in the post above, I used these in the early 80s with a crappy tin box arc set, and ditto the carbon rod brazing was its most useful function, it was crap for welding.
I found carbon arc brazing was quite good for what I was doing (I've also done a bit of O/A brazing for comparison ) if you've got the stuff give it a go, it's certainly another useful bit of kit in your arsenal IMHO.

Ditto that.
I hunted around found another carbon arc brazing holder for my buzzbox and gave it a try after a long gap. Previously, I'd had some good results brazing up a Landy diesel tank, and really got my eye in with that (not arc eye) and was hoping to quickly regain that touch.
Humm... well, yes and no. Insofar as I did successfully braze some bog chain to some bolts, it can be counted as a success, but it wasn't neat or tidy.
As said above, practice makes perfect and it's certainly cheaper to run than getting in extra gas kit and associated bottles.
I'm keeping it aside for nut-heating, steel bar bending, and the odd bit of brazing I might get up to.

 

[BarrieJ]

Much as the two post above ref using just a buzz box back in the day. The 8mm ones would light ok.
You could try getting the carbon rods from machine mart as they use to still sale them (just had a quick look and can't see them on there site )
Might be worth looking at the "specs" of the gouging rods to see if they mention arc brazing or look up carbon arc lighting !. If you are not already aware you need a welding mask not goggles for using.
I seam to recall there was even a medical treatment using the light produced from these rod
If all the 6mm bit you still have are long enough you could make up some holders to fit them into. see pic.
When I was using one of these years ago to weld in some floor patches I was getting the welds crack just after finishing a run. Mentioned this to a work mate and he said that due to the carbon being introduced in to the weld pool the welds would be brittle and crack, so just be aware of that.
There was also a "spot welder version of the carbon arc that used just one carbon rod.

View attachment 379003

You're right about the medical treatment, an uncle of mine damaged his spine in a mining accident and used such a lamp for treatment. I think it was made by Pifco? He'd wear a pair of actinotherapy goggles which were like vintage Oxy/Acetylene welding goggles. Incredibly bright white light and a loud buzzing.

 

[8ob]

I bought a buzbox when god was a boy and that came with a carbon arc torch, I remember the "flame" for a better word always being a lot wider than OA. That said it was possible to braze with it to an acceptable standard.

Bob

 

[Porkypine]

I'm becoming tempted to get a set now!

 

[mike 109444]

Note this extract from the hobby-machinist web sit I linked to. May explain some issues you may have had.

"A word of caution if you are going to use AC power use AC Carbon Arc Rods, DC Rods will not function correctly on AC.
i found that out the hard way......
You can use the TCA in DC but you will need a large DC rod and a small DC rod, because the rods in DC do not get used up at the same rate.
For AC you can use the same size rods as they are consumed at the same rate.
i hope the info helps out!!
mike)"

 

[nickjaxe]

Ok guys......the 8mm carbon rods were no good on my old 110amp oil filled Oxford Are for use with my carbon arc torch.....the welder was made in UK a long time ago as I stated in my last post....bought by me brand new when I was 18 and knew zero about welding......

Anyway as I said in my original post.....the carbon arc brazing torch I had maybe 40 years ago was ok back then for me only used it for brazing.

I thought about digging the carbon narc out again to use for heating things now as well as any brazing I may need.

Anyway I ordered some 6mm rods....they came a few days ago.....tried them today....what a difference over the 8mm....good stable flame....good arc.

Must have been 6mm rods I used all those years ago.....anyway.....put a bolt of 1/2inc dia in the vice....heated it till red right through in maybe 30 secs.....did not time it but I was happy with it.

Thin 1mm plate was putty for it....
I think its going to come in handy for the odd heating and brazing job in future....not a thing I will use very often.....but its there costing very little....

I have 10 carbon rods.....not sure if I should buy any more.....I am 70 now.....not sure how long I will be dabbling with stuff????

The yank do one of these torch's made by the famous Lincoln Brand company.....looks a great bit of kit....would love one.....not made now and prob for many years.

Wish I had the spot weld attachment for this torch....would have liked to have tried it.....looks simple to make one.

Its in the kits instruction leaflet I have.

Thanks guys for your help.

 

[Cobbler]

Something I was told years ago, was to also connect a return clamp to the work piece as well as the torch return, apparently it makes the arc more stable in relation to the work. I have no idea whether it works or not as it was a borrowed torch & I gave it back soon after.