Early Days....Gaining Restoration Skills - MotorRetro

[Oldman]

This was where the really valuable experience of these guys helped me understand the benefits of different welding processes.
All up, I would use MIG, TIG and Oxy. to join panels without and with filler rod.
(Oxy !!, yeah...who uses Oxy. on panel work ? .........this one really blew me away......to follow...)

Onto the TIG....
What I learned first up was the difference between the result of MIG vs TIG and it is worth highlighting I think....

The MIG welding process hardens the metal you are working on and with.....TIG does not .
This means that a MIG weld is more likely to fail/crack when subject to vibration - think moving vehicle - than TIG, that retains the same strength and characteristics of the base metal.
A MIG weld will also chew through flapper discs at a great rate as hardened steel is being ground down.....
A MIG weld is extremely hard to shape .....a TIG weld is not...think making a complex panel section that requires rolling/shaping before fixing to the vehicle.

I've often heard that,
"....the difference between a good (MIG) weld and a bad one is 10 minutes of grinding...."
Man, have I seen that myth blown out of the water and into the Stratosphere !!
Imagine a MIG weld without proper penetration, ground back, bogged over and painted......it's bound to fail, crack, let water in and rust all over again.

With TIG, I can work the welded sections exactly as if they are one piece of metal....it can be planished, rolled, cold stretched and shrunk without failing.
(Assuming the penetration is there....)

So, first runs with the TIG....2.4mm Tungsten, 1.0 mm sheet, just getting used to the arc.

   

No good !! No weld pool or penetration .....had to start somewhere !!

   

Slowly getting better.....but what about penetration ?

   

Yeah,..........Nah !! Gotta work on that......and practice I did.

   

Looking ok on top...penetration ?

   

Pretty happy with that.
All these joins are without filler....just metal to metal joined by TIG arc.
Next was to introduce a filler rod......