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MIG tacks beading (newbie)

Posted: Wed Dec 09, 2015 8:25 pm
by danyboy741
My wife bought me a welder for my birthday, it's a 120 Volt, 70 Amp, MIG welder that came with a regulator that does not have a flow gauge. My plan is to weld thin steel sheet metal for car body work. I got a gas bottle and I am using 0.024" wire.
The problem that I have is that I cannot even do simple tacks. The tacks that I do don't flow or puddle, there seems to be penetration, but they simply bead on top of the metal piece. I tried all the combinations possible more/less speed, more/less power, it doesn't change.
Is my problem one of lack of power (only 70 amps) or a bad gas flow setting, or something else I didn't think of ?

Re: MIG tacks beading (newbie)

Posted: Wed Dec 09, 2015 9:37 pm
by VincenzioVonHook
danyboy741 wrote:My wife bought me a welder for my birthday, it's a 120 Volt, 70 Amp, MIG welder that came with a regulator that does not have a flow gauge. My plan is to weld thin steel sheet metal for car body work. I got a gas bottle and I am using 0.024" wire.
The problem that I have is that I cannot even do simple tacks. The tacks that I do don't flow or puddle, there seems to be penetration, but they simply bead on top of the metal piece. I tried all the combinations possible more/less speed, more/less power, it doesn't change.
Is my problem one of lack of power (only 70 amps) or a bad gas flow setting, or something else I didn't think of ?
If you are welding car panel (around 0.8-1mm?) 70A should be fine. I normally use the lowest setting on my mig to weld car panel. Im pretty sure that is 35A. That welds 0.8/1.2mm ok, and 70A roughly welds 1.6-2mm max. Does you welder have any power settings? Or is it 70A only? Play with your wire feed extremes and get a feel for the sound. Turn it way to low, and you will here a intermittent hissing, as the wire burns off before it hits the job. Turn it to the other extreme (too fast) and the Arc will be erratic, and the wire will be stubbing on the job, pushing the gun around in your hand. Wire feed is really the key when you have a small amount of power to play with and you are welding thin sheet.

If you are welding with Gas shielding, do you know if this welder was set up for gas or gasless welding from the shop? The gun should be connected to the Positive terminal and the work lead should be connected to the negative if you are running with gas. If you are welding with gasless wire it should be the other way around. If your welder is using a shielding gas and you have the polarity wrong, it will bead up and lack penetration. The only positive of running straight polarity on a mig is the ease of closing gaps on really thin sheet (0.55) maybe.

Re: MIG tacks beading (newbie)

Posted: Thu Dec 10, 2015 9:40 am
by Mike
Welcome to the forum.