Tig with Mig

[rnln]

Hi guys,
This guy is using the Mig machine to Tig. If this can work, I will be able to get my hope up on welding aluminum and SS with my Mig machine again . Has anyone tried, or if knowledge/experience people can share some thoughts?
Thanks

https://www.youtube.com/watch?v=y0uZO9vwE5o

[1990C4S]

I'm very suspicious. TIG machines have a lot of features that MIG can't do. High frequency, starting routines, etc.

Maybe you can make it work, I would guess it's very difficult.

[unclebilly]

For aluminum TIG, you need Ac and continuous high frequency to keep your tungsten clean.

MIG welders don’t have continuous HF or even HF start. The welder shown is DC as well as are most MIG welders but could be wrong on this point.

This would be lift arc only and won’t work for aluminum at all.

Neat idea though.

[Zeke]

Originally Posted by unclebilly

For aluminum TIG, you need Ac and continuous high frequency to keep your tungsten clean.

MIG welders don’t have continuous HF or even HF start. The welder shown is DC as well as are most MIG welders but could be wrong on this point.

This would be lift arc only and won’t work for aluminum at all.

Neat idea though.

He said "scratch start" and it would have to be that. No HF but the tungsten would be hot when the trigger is pulled. If you're in contact with the weld material when you pull the trigger all you're gonna do is stick the tungsten.

What he is doing is no different than using s TIG torch with an old buzz box stick (SMAW) welder with a manual gas valve.

I think his current was too high. He could have had a helper turn it down once he had an arc started. That is if the MIG had a continuous voltage adjustment. So many of the little ones are tapped (or stepped voltage settings) machines and can't be adjusted on the fly.

TIG machines are so cheap these days that if you can afford an argon bottle, you can afford the welder. Conversely, you can spend a small fortune on a really nice MIG. I've used one of those and it's miles ahead of anything under $700.

[908/930]

As unclebilly said, really need the continuous high frequency and AC output, also post flow on the torch and lots of current for anything over 1/8 thick and at that point water cooled torch is req. Just start looking for a used TIG, the older ones are out there, I gave mine away years ago, it was 800lbs and didn't want to move it. To weld S/S that could work, but get a proper torch with a gas valve on it and you will probably need to regrind the tungsten after every weld, a car battery would work for a power supply just don't weld near it.

[rnln]

I get it as not worth the try, right? He did said that it is really hard. Another clip showed that it looks really ugly .

[Dpmulvan]

Originally Posted by unclebilly

For aluminum TIG, you need Ac and continuous high frequency to keep your tungsten clean.

MIG welders don’t have continuous HF or even HF start. The welder shown is DC as well as are most MIG welders but could be wrong on this point.

This would be lift arc only and won’t work for aluminum at all.

Neat idea though.

Not true.
Ac balance controls cleaning action of the part being welded, it’s measured by % of electrode negative or positive.
AC frequency is measured in hertz and controls focus of the arc. Lower frequency wider puddle higher frequency more of a pinpoint thin puddle.
Old machines transformers had a non adjustable 60ish Hz.

[unclebilly]

What part of my post is / is not true? I think everything I posted is accurate and your post seems to confirm it...

Any repeating event including voltage alternation can be measured in Hertz. It is basically cycles per second.

The point of my post is that aluminum TIG is done with AC, most wirefeeders are DC.

The HF is used for tungsten cleaning.

I’m confused.

[Zeke]

I've never heard of "tungsten cleaning" unless you are grinding it to a point or a blunter shape for some AL welding. The balance refers to how much time the current spends pos or neg in the cycle. Yes, the 'cycle' can be changed by adjusting the Hz, but the Hz wave pattern can be changed as well. You either got more cleaning of the weldment (not the tungsten) or more penetration depending on the wave pattern.



In any event, no MIG process will do that. Strictly for DC welding.