MIG porosity?

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OK I'm stumped. I have a Millermatic 250 which I believe to be in excellent working condition. I'm running C25 through a Harris 355 flowmeter, set to 25cfh. The gun is fully seated into the welder. I have cleaned the consumables under the nozzle and reamed the nozzle. The gun (a stock-standard Miller M25) isn't kinked.I believe my machine is set correctly. Yet I'm getting porosity. It's driving me nuts. There's still 600 psi showing in the cylinder (a 251 cf cylinder) so it should hang on for a long time.I'm welding inside, about eight feet inside a double garage door which is cracked two feet at the bottom. The more I weld it seems like the worse it gets.Ideas?
Reply:Bad wire or dirty steel. I dont know how experienced you are but your stick out could also be a factor.Lincoln Ranger 250 GXTLN-25Lincoln Magnum SG and ModuleAirco HF BoxMiller 304 XMT CC/CVMiller 60 Series FeederMiller Syncrowave 250O/A SetupIt's a dog eat dog world and i'm wearing milkbone underwear
Reply:It sure isn't a stickout issue.More. I shut the garage door and turned the flowmeter up to 35cfh. No help. Really scratching my head. I decided to swap MIG machines. Same problem. It's got to be the steel somehow. The steel is new plate which has been around awhile, has a light haze of rust which has been 99% knocked off with a power wire brush.Guess I'll stick weld it. 6010 will burn through whatever it is!
Reply:make sure your gas is getting from the bottle to the nozzle, maybe a leak? At work we have to check with a flow gage, usually have the suitcase 60 feet from the tank. But just because at the bottle your reading 35 doesnt mean your getting that at the nozzle.25 years of age.Been welding since Feb 23rd 2009.LU1007 Millwright (A1)
Reply:Originally Posted by B.Appelmake sure your gas is getting from the bottle to the nozzle, maybe a leak?
Reply:Try pushing your weld instead of pulling and see if it stops the porosity.
Reply:My very limited experience: Try turning your gas down to 20 CFH, make sure your torch angle is close to 90 deg to the weld, dirty/rusted wire will give you fits.Again I have very limited experience, but these are the things that usually get me.
Reply:Did you try welding a different piece of steel to confirm your theory?Miller 250x & Lincoln V205-TSmith Oxy-Prop torch
Reply:yeah some metals just don't weld very well.........  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Originally Posted by metalmagpieOne machine might have a leak, but for the one next to it to have developed the identical problem kind of rules that out. I'm thinking now it's just too corroded for MIG.
Reply:Originally Posted by B.AppelDid you use the same regulator for both machines? Same hose?