[TheForge] MIG Question

[Todd Rich]

On Thu, 11 Oct 2007, Washington, Aubrey O. wrote:

> Okay, here is a metal-working question.  A few months ago I asked the 
>group for input on MIG welders and got a lot of good suggestions.  Since 
>I'm just one of those "hobbyist" guys, I didn't need anything big and 
>fancy so I got a Millermatic 140.  Pretty much straight out of the box I 
>was able to do decent welds and I was happy.  However, over the weekend I 
>tried to do a few welds in 14 ga. mild steel and they looked awful.  They 
>were pitted, porous, and uneven.  The tip was spattered and dirty, so I 
>replaced that, with no improvement.  I'm using Argon/CO2 shielding gas. 
>But I'm not sure if I have the right pressure setting.  Any suggestions?
>
> Aubrey

Well, that definately sounds like a lack of shielding gas.  However using 
my 251, it isn't the tip getting dirty, it is the nozzle around it getting 
build-up on it.  It should just pop off, but if it doesn't, I'll use a 
small flat-bladed screwdriver or something similar to pop the crud off. 
However if you are clean and it still isn't welding right I'd check to see 
if you can hear gas flow when you are running.  Turn the wire feed down as 
low as you can and hit the gun trigger and see if you can hear any gas 
flow sounds.  If not there may be a problem.  Most people I know run their 
C25 gas between 20 and 30 CFH.  Another trick you can try if you aren't 
hearing gas is turning off you tank and hitting the gun trigger.  If the 
gauge goes down, you know your problem is after the gas solenoid, if it 
stays where it was, your problem is on the upstream side of the solenoid.

Hope that helps.