Brazing Copper to Steel

Do you have MAG? With simple steel wire, you can easily weld the copper to the steel. Takes a bit more power and one or two tries on some scrap. Direct the arc more to the copper.

Nick

I don't see why there should be any problems, I've brazed brass to steel many times, also probably copper to steel but can't remember specific occasions. You'll probably have to get the entire piece of copper to near brazing temperature because of its high conductivity.

Tim

In message , Andrew Mawson writes

I have had no problem brazing stainless steel super-heater tubes to copper fittings using J.M. 'Argobraze 56' and 'Tenacity 4a' flux.

scrap.

TIG and MIG and arc yes, but not MAG - I'll probably do it with oxy-acetylene though.

AWEM

single

That's encouraging

No real problem, these links are only carrying a few tens of thousands of amps circulating current !

AWEM

I might be wrong here, but isnt MAG MIG with CO2? Its only MIG with an inert (argon usually) gas, Metal Active Gas welding is done with a non inert gas, iirc usually CO2.

FWIW Ive OA welded copper to copper, its possible, but there is only a very short 'puddle time' before it ends up as a hole. I suspect copper to steel brazing would be reasonably simple, brass to steel is, I used a prefluxed rod of uncertain parentage (I *think* it was fluxobronze K, it was what was to hand).

Dave

MAG is MIG with CO2 :-)

Mark Rand RTFM

And oxygen as well I thought?

AWEM

If you have MIG, you have MAG. Just swap the bottles. :-) (I know, that many US can't distinguish between MIG and MAG, but the UK-people?)

MIG: Metal Inert Gas (Ar, He) MAG: Metal Active Gas (CO2, Ar/CO2 mixes, tri-mix, ...)

I did it with Ar/CO2 18%. Maybe you'll get a problem with pure CO2, but pure Ar should work without problems.

Nick

MAG means that it contains *some* active gas. It doesn't mean that it is pure CO2. Here, the Corgon-mixes ([tm]by Linde of course; Argon with

But maybe I'll switch. Last 20l tank (200 bar) costed 50.- EUR. :-(

Nick

In message , Andrew Mawson writes

When brazing, the joint is made at red heat so the copper will be very 'soft' and thus very compliant in comparison with the steel as they both cool. Until someone with expert knowledge comes along to say otherwise I will argue that initial stresses in the cooled joint will be low and will remain so unless and until other factors cause the copper to move and to work harden.

otherwise I

Sounds very plausible - yes I'll buy that !

AWEM

On or around Sat, 31 Mar 2007 00:26:48 +0200, Nick Mueller enlightened us thusly:

Air products COOGAR 5 is what I use here for steel. I forget the actual percentages.