Need answers to a regulator issue.

[ouibus]

I am having some issues with the regulator on my Miller 172. I am using a 75/25 mix with the machine. I have had a problem ever since I switched from flux core to gas shielded.
Here is what is happening. When I first pull the trigger, a burst of gas comes out, but then it just about stops flowing. So much so, that I would rather use flux core on this machine rather than trying to get it to weld right with gas. About 30-40% of the time, the weld is really porous and splotchy. I am constantly having to grind down what I just welded and go back over it to get good penetration. I have spent a long time tearing down my machine trying to find out what is wrong, but to no avail. Finally, I came to the conclusion that the problem was with my regulator. I tested this theory by borrowing my friends regulator and wouldn't you know it, my welder worked awesome using his. So I take the regulator back to the place that I bought it and they send it off to be serviced. Well it comes back, they charge me $17, and when I get home and open the box it was sealed in, I find out that apparently don't find anything wrong with it. So, I hook it back up to my welder and it still does the same thing as before, but it seems to be welding a little bit better now. But that is welding on completly new and clean piece of steel in perfect conditions. I imagine when I start welding on my rig, I will encounter the same problems.
So my question is, have any of you guys heard of something like this, and if so, is it a very common issue?

[jeeplord]

did you reverse polarity when you switched from flux to solid?

[ouibus]

Yes I did. After messing with it for so long, and it still having issues, I took it to the same welding shop that I took the regualtor to and the tech guy checked it all over and said it should work. Of course when he went to weld with it, it welded fine. Almost as soon as I brought it home, it started acting up again.

[MuddMachine]

Could be a leak in the feeder. Ive never had a reg problem in all the years ive been welding. Seems they work or they dont. Are you welding on clean steel?

[64Trvlr]

Yes I did. After messing with it for so long, and it still having issues, I took it to the same welding shop that I took the regualtor to and the tech guy checked it all over and said it should work. Of course when he went to weld with it, it welded fine. Almost as soon as I brought it home, it started acting up again.

Did the reg work on a different machine? If so the problem might be with your machine or gun/liner.

[MuddMachine]

Did the reg work on a different machine? If so the problem might be with your machine or gun/liner.

A contaminated liner will mess up alot of stuff. Is your difuser clean?

[maddog]

What air flow are you running at? Inside or outside your shop?? When you tried your friends regulator was it at your house or shop with the same amperages?? What are your settings and line speed? What size wire? Lots and lots of variables.

[ouibus]

Did the reg work on a different machine? If so the problem might be with your machine or gun/liner.

I tried my regulator on my friends machine and it worked fine. I find this funny considering that I used his regulator on my machine and my welder worked great then.

So that means my suspicion about my regulator was wrong, but that still doesn't answer why I am having problems.

[ouibus]

Could be a leak in the feeder. Ive never had a reg problem in all the years ive been welding. Seems they work or they dont. Are you welding on clean steel?


The test welds I have been welding on are on clean steel and they come out ok, but I have welded on celan steel in the past with the same results.

[ouibus]

What air flow are you running at? Inside or outside your shop?? When you tried your friends regulator was it at your house or shop with the same amperages?? What are your settings and line speed? What size wire? Lots and lots of variables.

I am running around 16 PSI for gas flow. I am welding inside my garage that does not have a draft or air blowing. I used my friends regulator on my machine in my garage with the same settings. I am using .030 size wire with a 12 ft. Tweco gun. I generally run a pretty low line speed with heat set on either 3 or 4 out of 4. I am usually welding 3/16's to thicker steel. Sometiimes it will weld great and other times it won't weld a decent bead to save it's life.

[ouibus]

A contaminated liner will mess up alot of stuff. Is your difuser clean?


Oops, almost missed this post. The gun is fairly new so I don't think that I have a worn out liner. Also, my diffuser is clean and working well.

[64Trvlr]

Oops, almost missed this post. The gun is fairly new so I don't think that I have a worn out liner.

Pull the liner and check it.

[TLCObsession]

I run closer to 24, 30 if I am outside.

[ouibus]

I run closer to 24, 30 if I am outside.

I run between 15-17 as per the instructions of a welding instructor I know. I have tried it on a higher setting and it has similar issues.

[maddog]

Maybe check the gauge. 16 PSI may well not be the correct reading, or your spool speed may we off. Any tension setting on the spool? Crank it (PSI) up on different levels and test weld. Porosity can be several different reasons. Nozzle or tip dirty? Use nozzle dip. Helps out a lot for both nozzle and tip. Wire speed at voltage 4 /.030wire usually requires around 60 to 65 wire speed with 75%Orgon/25%CO2. Is your wire clean? I keep my extra spools of wire on top of my water heater next to the “B” vent. Warmest and driest constant air in the garage. Are you inadvertently moving your nozzle further away from the weld as you lay your bead. Learn hand placement, line of travel and support to keep a steady bead keeping the nozzle within ¼”-½” of weld ALL the way through the weld. When you tested your Regulator at your friends, was that on his bottle? Maybe you have some bad gas in your bottle and need to have it changed. Other than that I can think of nothing else other than maybe get a line voltage reading at different times of the day. I know here in Victorville if I have any serious welding to do I’ll do it earlier in the morning hours rather than in the evening hours when the electricity demands are higher and Edison does a voltage % cutback. Good luck! Trial and error and each machine has it’s own characteristics.