Bad Gauge, Regulator or Both?

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I started welding with my MIG, and noticed brown soot in the weld.  Figured I wasn't getting any shield gas.  The tank pressure gauge is working and shows 1500 PSI of Argon.  The Argon gauge is stuck on 12 CFH.  Obviously no argon is passing through the system.  Disconnected the Regulator and the Tank Pressure gauge dropped to zero, the argon gauge is still stuck on 12 CFH.  Will a bad gauge in and of itself cause the gas to start flowing, or is the regulator a problem that destroys the gauge?
Reply:The gauge si probably faulty. I prefer flow meters myself, and eventually replace any of the gauges that come with the welders. You can buy the flow gauges that you place over the MIG nozzle to measure gas flow- with the wire feeder turned off or drive roll pressure released.I hope you are welding aluminum if you are using argon shielding gas. If you are welding steel and arent getting any shielding, you will get a lot of porosity, not soot.
Reply:The gauge has nothing to do with the output of the reg.  A bad reg could damage the LP gauge however and so a damaged gauge could be a symptom of a bigger issue. Usually when a reg goes bad it fails open, that means it leaks gas, not stops in most cases. If the HP seat failer the preasure would continue to climb on the LP side until the needle pegged at ot above max, usually bending the needle and giving a false reading above what the reg is set at. At some point if this happens the hose either bursts or more likely the reg vents and leaks gas to relieve the pressure.No gas can be caused by debris getting in the HP side from the cylinder valve and blocking the small HP orrifice in the reg. With most small regs it's often most cost effective to simply replace the reg with a new one rather than rebuild it. With better quality regs, it's better to rebuild the reg. OAdoctor here can take care of you if you choose to get the reg rebuilt. He can let you know if the model you have is worth the money for a rebuild or not, and he can hook you up with a rebuilt or new reg if you choose that route..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Originally Posted by Pro-FabI hope you are welding aluminum if you are using argon shielding gas. If you are welding steel and arent getting any shielding, you will get a lot of porosity, not soot.
Reply:Originally Posted by DSWThe gauge has nothing to do with the output of the reg.  A bad reg could damage the LP gauge however and so a damaged gauge could be a symptom of a bigger issue. Usually when a reg goes bad it fails open, that means it leaks gas, not stops in most cases. If the HP seat failer the preasure would continue to climb on the LP side until the needle pegged at ot above max, usually bending the needle and giving a false reading above what the reg is set at. At some point if this happens the hose either bursts or more likely the reg vents and leaks gas to relieve the pressure.No gas can be caused by debris getting in the HP side from the cylinder valve and blocking the small HP orrifice in the reg. With most small regs it's often most cost effective to simply replace the reg with a new one rather than rebuild it. With better quality regs, it's better to rebuild the reg. OAdoctor here can take care of you if you choose to get the reg rebuilt. He can let you know if the model you have is worth the money for a rebuild or not, and he can hook you up with a rebuilt or new reg if you choose that route.
Reply:You should be able to HEAR gas when you pull the MIG gun trigger. Since welding is noisy, release the drive roll tension so the wire doesn't feed. Pull trigger, listen for gas flow at nozzle.If gas doesn't flow, disconnect the gas hose. Open gas cylinder valve then open regulator valve. Gas should flow freely with regulator adjusted open, and stop when regulator is adjusted closed. If regulator "passes gas", and welder doesn't,  problem is welder. Gauges are cheap. Post pic of regulator. Your LWS can test it (essentially the same way) but WATCH what they do so YOU learn how to do it in the field.
Reply:Thinking on this a bit, it might be an issue with the gas soleniod in the machine if you are actually not getting gas at the torch. This could be a mechanical issue with the solenoid, or an electronic one with the machine not actuating the solenoid.You can tell if the reg is passing gas by simply unhooking the output hose from the reg or the back of the machine and listen to hear if the gas is escaping with the reg turned on and up a bit. It should be clearly discenable if it's not too noisy in the background.If it seams you are getting gas from the reg, but not from the torch, then post up your info on the machine and one of the machine guru's can help you trouble shoot the problem in the machine..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:The machine is a Miller 135.  I am definitely not getting gas at the tip.  I've already pulled the regulator, will try to get it to the shop tomorrow to be checked.  If everything checks out, I'll try farmall's suggestion.  I suspect a bad regulator, but you never know.Thanks guys.
Reply:Thank you for the help guys.  It was a bad case of a bad gauge and operator error.  The regulator and the solenoid are good.  Once the new gauge went on, figured out that the regulator was not cracked open enough to allow gas to flow.  New gauge, everything re-set.  Life is good.
Reply:Thanks for letting us know. Glad to hear it's up and running again..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Yeah, thanks for the follow up. Happy MIGing!