Mig/mag

Belgian1979vette

Belgian1979vette

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Joined
Apr 4, 2008
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Location
Koersel/Belgium
Guys,

I have a question about MIG/MAG welding. Currently I had to tun my CO2-bottle in. However I do have a bottle of pure Argon for welding with my TIG. Could I use this bottle also with the MIG ?

Thanks

Yves
 
No, pure argon will give you very poor wetting. Get some 75/25 mix or thereabouts.
 
I worked at a plant in the 80's that tried Argon with mig, it gave pretty welds but not deep penitration. I agree with TT use a mixed gas
 
Anyone know WHY this is so??

I would think any inert gas would work the same....:chinese:
 
mrvette said:
JeffP1167 said:
Belgian1979vette said:
Guys,

I have a question about MIG/MAG welding. Currently I had to tun my CO2-bottle in. However I do have a bottle of pure Argon for welding with my TIG. Could I use this bottle also with the MIG ?

Thanks

Yves
Click to expand...

Super glue does a far superior job then welding.
Click to expand...

OR soldering......:lol: Rite Jeff??
Click to expand...

nah zip ties stronger then solder. bet your wondering just how long my 90 vette will last with all this advanced technology
 
OR soldering......:lol: Rite Jeff??[/QUOTE]

nah zip ties stronger then solder. bet your wondering just how long my 90 vette will last with all this advanced technology[/QUOTE]

I had a '87 vette which I sold to buy this '72, some 15 years ago....

several reasons for the move....but the largest reason was the terminal poor design of the weatherstriping, it's open cell foam and in Maryland where it rains a lot, that leaked like mad, new foam was super expensive and made the same way, so it wouldn't have lasted long either....I got tired of all the dripping/leaking into the car....
my paint sucked, clearcoat was going on the back deck, finish was dull all over....and the tranny was doing the typical GM tranny trick, starting to turn brown/dark even after changing....time for clutches/rebuild....being a 700 I had NO idea about them in those daze, NOW having rebuilt one for the motor home here, I do..it's expensive to make one right, nearly a grand in parts alone....

even with that Digital dash, the electronics never gave a second's trouble...none of it....but the alternator was exchanged about 3x in the 3 years I owned it....even the infamous headlight motors were fine....

:cool: as you maybe know, I have a modified TPI type setup on my '72, roller engine, speed density....:D
 
mrvette said:
Anyone know WHY this is so??

I would think any inert gas would work the same....:chinese:
Click to expand...

When I worked in the welding shop in the early 80's we tested different gases and found CO2 to give the deepest penitration with the most spatter and Argon the shallowest with the least spatter. I use a 75/25 mix for all my mild steel welding with Mig. something to do with how the different gases react to the arc (can't remember that far back)
 
Exactly, CO2 content has a direct influence on welding heat but apart from that there wetting is much better with CO2.
The weld pool flows into the parent material much better with less weld build up. Stainless MIG for instance is next to impossible to weld with straight argon and MIG. With TIG you use straight argon. MIG welding stainless is done with mix too. Gold mix CO2/Ar/He (trimix) is a waste of money for your application.

The higher the Ar content the less spatter indeed and the cleaner the weld bead.

Argon is inert, it does not react with the weld. CO2 is not inert, it does react. That´s why CO2 wire feeding is actually called MAG Metal Active Gas instead of Metal Inert Gas. Argon gives a narrow arc and a narrow penetration profile. This is why it has poor wetting, the parent metal does not readily melt and flow into the bead. Thatäs why you need an active oxidiying component such as CO2 It also stabiliyes the arc. Straight Ar is simply not suited for welding ferrous materials.

The reactivity of the CO2 is what creates the intensive spatter. Straight CO2 should therefore be avoided, a 25% Ar content severely reduces spatter.

If for some reason carbon infusion of the weld should be limited a choise of trimix would be better Helium has great thermal conductivity and it improves penetration but requires more amps to ionize. A 2% content of CO2 added improves the stability of the arc without excessive carbron infusion.

Another thing to note is that straight CO2 is limited to short circuit and globular transfer. No spray transfer.
 
:shocking: I wuz hoping TT/someone would answer, too bad I don't unner sand a thing he rote......

thanks man.....:beer::beer:
 
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