[BigTonyB]

I've had my Old Airco TIG welder for a long time, but only used it for welding aluminum. I now want to use it for some steel parts while building my old truck. I have 15 pounds of copper coated steel rod that I used with my OA torch.
I've been using this rod to practice my TIG welding, and have even fabricated some non-critical parts. The welds look good, and test pieces have survived the "smash it with a BFH test" Is there really any difference between gas welding Rod, and TIG rod?
Thanks.

[MinnesotaDave]

As I remember the differences, R45 or RG45 are designed for oxy/fuel (they are 45,000 psi rods).

Tig rods such as ER70s-2 are correct for tig and can also be used for oxy/fuel.

[plain ol Bill]

Save yourself some grief and just go get some 70S2. If you use the gas rod the weld will be FULL of porosity.

[noddybrian]

Unless it's different across the pond very very old gas rod could be unknown or unsuitable but stuff made relatively recently tends to be graded here as A15 or A18 - copper coated but un-stamped - this is effectively ER70-S2 & S6 if you look up the spec - maybe not not held to quite the exact tolerances of sold as Tig rod - but perfectly OK to use - only real difference is it has no stamp mark on the rods so the only batch number would / could be on the carton making it unacceptable for a coded / test piece - if used on your own private jobs should work fine - I have some A15 I use sometimes & only time I had porosity issues was due to joint position / torch angle / stickout issues that I should have known better !

[BigTonyB]

Thanks for the replies, Guys. I guess I'll just use the gas rod for running practice welds, as I can't see myself going back to OA welding, and I'm too much of a cheapskate to throw it out.
I'll get some er70-s2 for my real projects "just in case".
I would still like to know why it shouldn't work, though. After all, in OA welding, you're still dipping Rod into a puddle as in TIG.
I like to understand why, as opposed to "just don't do it!" Of course, that's what got me in so much trouble as a youngster!
Thanks again.

[noddybrian]

I think in laymans terms rods for gas welding used the flame primarily for cleaning action in that most impurities would float to the surface as an oxide layer or burn off in the flame helped by the pressure from the flame pushing almost a " bow wave " effect into the puddle with most impurities being pushed ahead of the flame & out to the edges - with Tig there is very little push effect so the puddle largely is'nt disturbed so the impurities need help collecting & floating to the surface also there is no cleaning action from the gas as it's pure argon - this is what the silicon does in part as it does also in Mig wire bonding with impurities & floating to stay on the surface - S2 has other additives to assist this process - this is also why it was possible to gas weld with any available wire after a zombie apocalypse ! I've used coat hangars & fence wire in the past ! - best advice though is whenever possible don't complicate things trying to get by with questionable consumables - always strive to use the correct ones kept in good condition & fresh whenever feasible.