Mig or tig, Which would you choose? Options

[r_towle]

Lots of sheet metal body welding, flares, patching, several cars.
I did use a mig for years, upgraded to gas mig.
My son took it.

So, I’m getting another welder.
I still have a gasless mig, and a scratch start tig
Neither are very good.

So, which would you choose? Why?
Willing to take the time and learn.

Rich

[Superhawk996]

@nathanxnathan

I hear ya. (IMG:style_emoticons/default/happy11.gif)



Even in this case - all 3 layers were new and clean but still had major episodes of splattering weld puddle that contaminates the electrode.

Good example where TIG was not the best tool for the job. Would have been much better to have done this with MIG but I didn’t have my MIG available.

FYI - my solution here was to downsize the electrode to 0.020” (pulsed at 2-3 Hz) to get in the hole down to 1st layer get the puddle between 1st and 2nd layer started then feed 0.023 MIG wire in as the filler and fed it in fast to get the inner layer fused. Then let it cool - repeat for 2nd and 3rd layer. Took way too much time for each puddle weld. (IMG:style_emoticons/default/headbang.gif)

[914_teener]

@nathanxnathan

I hear ya. (IMG:style_emoticons/default/happy11.gif)



Even in this case - all 3 layers were new and clean but still had major episodes of splattering weld puddle that contaminates the electrode.

Good example where TIG was not the best tool for the job. Would have been much better to have done this with MIG but I didn’t have my MIG available.

FYI - my solution here was to downsize the electrode to 0.020” (pulsed at 2-3 Hz) to get in the hole down to 1st layer get the puddle between 1st and 2nd layer started then feed 0.023 MIG wire in as the filler and fed it in fast to get the inner layer fused. Then let it cool - repeat for 2nd and 3rd layer. Took way too much time for each puddle weld. (IMG:style_emoticons/default/headbang.gif)

This is an application for spot welding.

What is happening is the gas between the layers (O2) expands and when the puddle melts contaminates the weld.

So to TIG weld three layers the weld design is better if a plug weld is used....drill with a spot faced drill through the first two layers three times the dia of the thickness of the metal and fill up the hole.

In my opinion becuase of weld deposition rates (time) MIG is better there given that application.

If no MIG is available...pulse is a good decision and a gas lens...if you don't have a gas lens stuff some 3M scotchbirte in a #8 cup.

No charge.

[Superhawk996]

@nathanxnathan

I hear ya. (IMG:style_emoticons/default/happy11.gif)



Even in this case - all 3 layers were new and clean but still had major episodes of splattering weld puddle that contaminates the electrode.

This is an application for spot welding.

Agreed but sometimes we have to make do with the tools we have at hand.

The problem is that spot welds can be one of the hardest weld processes to get a good solid weld in a home shop environment. Lots of variables: clamp pressure, current/voltage, cycle time, tip geometry. I’ve seen bodies from OEM assembly plants scrapped due to spot welding process that went out of whack.