MIG Welding

[Glenn 'Stinky' Stankevicius]

Got some real problems with the MIG at the moment. Most welds are crappy with poor metal penetration, bubbly finish and it is hard to keep the arc going once started.
I have recently replaced the Ground lead, the inner core for the feed wire and the wire speed control.
Any ideas? can MIG gas go "off" as I have had the bottle for a while. I am reluctant to spend any more money when I can pick up a new unit for $500-600.

[nicko]

i have just had similar problem and after changing the inner core still found it was poor,turned out it was just the wire had powdery rust on it that i mistakingly thought should still work ok but it was sticking to inner core tube and not feeding fast enough.new spool of wire and it now goes fine.

[fastjbav6]

I was told the flow rate of the gas should be 18 litres/minute.

Seb

[Ed]

Stinky,

I had this prob, and the fact was the MIG just didnt have the amps to penetrate the metal.. the transformers deteriorate after a while.

have u replaced your contact tip?
when these get spattered their effectiveness is reduced.. make sure its nice and clean and shiny, dip the end in spatter guard/gel.

clean the insides of the nozzle too, this makes a difference, when every amp counts.

i run gas between 10 - 12 L/min, except if it's windy.. then i bump it up to about 15.

wire feed with the correct amps should affect the bead height, not really the penetration ur getting, especially on sheet.

If it were the gas, you would find the bead has the consistency of an aero bar (and u get entirely showered with sparks) but the welder still makes that "cooking bacon" sizzle.

Hope this helps.

Cheers

Ed

[Glenn 'Stinky' Stankevicius]

Thanks Ed, Seb and Nicko, looks like I might be buying a new one.

This one has lasted me well over 15 years (scarey when said aloud).

[Glenn 'Stinky' Stankevicius]

Hmmmm
Replaced the contact tip, cleaned the nozzle (with my new sand blaster )
Checked the gas flow on the regulator and it's 10L/min as it always has been.
Tried a weld on freshly blasted piece of steel, sparks everywhere, penetration looked OK. On closer inspection the bottom half of the weld looks normal and the top has the "Aero Bar" effect.
Something is up with the gas, you get the initial rush when you hit the trigger, but I can't hear much after that.

[Glenn 'Stinky' Stankevicius]

Woohoo!
Replaced the gas regulator and it's doing perfect welds now. Better to spend $100 than $500 odd on a new welder.

Got parts coming in all week, so hopefully a productive Christmas break will see the car rolling again (front-end detailed and back in) with the motor in and a good start on the wiring.