Tandem Welding

By galdad Date 01-20-2002 17:26

Hello All

I'm looking for information on tandem welding. I'm doing a T.R. on SAW vs Tandem welding for National Steel Car.
This process involves running two GMAW torch in tandem while welding steels used in rail car repair.
The first torch lays down the root pass, and the second torch washes the rest of the joint.

By dasimonds (**)

Date 01-20-2002 18:05

I'm not sure what T.R. is, but we ran a tandem SAW rig back in the shipyard. Lincoln LT-56. Quite a large machine as compared to the LT-7 tractor, but wouldn't it put down some wire. We averaged about 65 in/min. travel. The machine rooted with 3/16" and filled with 5/32" wire. Always seemed kind of backwards to me, but I worked quite well. It would fill and cap a 3/4" plate in 1 pass. Joint design as I remember was a 3/8" land, 30 degree bevel. I can't remember the amperage or voltage parameters. I do remember it was very picky as far as any type of gap in the root. No more than a 32nd? maybe. It's been so long since I've run one of them.
I think we also had an LT-7 tractor set up with 2 electrodes side by side, running 1/8" wire. But as I said, it's been more than 12 years since I've run one.
I'm sure Lincoln could steer you in the right direction.
I wish I could be of more help with the GMAW, but I never did anything concerning GMAW running in tandem.
I can't imagine a GMAW unit outperforming SAW.

Hope this helps.
Dale Simonds

By galdad Date 01-22-2002 18:09

Thanks for your input.
I can use this info to help get me started.

By sparx

Date 01-22-2002 18:31

speak to your welding equipment supplier about Esab automation or CLOOS tandem mig......amazing speed improvements over conventional welding.