I need help...

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Machine is a MM250X, .035 wire, straight CO2. Not sure what is going on, but today I have been fighting with porosity in the first 1/2" of nearly all my welds. I've been running about 22-25cfm on my gas and have made sure my metal is very clean but it still acts up. Tried adjusting torch angle, stick out, you name it. The welds seem almost violent at the start but then settle down and finish like normal. Any ideas??
Reply:My first thought is contamination of some sort, like oil.You may have oil in your weld at first, then as you move on you are hot enough that the oil is burning off ahead of your weld. Try taking a torch and heating up the weld joint for a while. Maybe   cherry red, then let cool back down a bit and run the bead. Let us know.Lincoln Power Mig 210MP MIGLincoln Power Mig 350MP - MIG and Push-PullLincoln TIG 300-300Lincoln Hobby-Weld 110v  Thanks JLAMESCK TIG TORCH, gas diffuser, pyrex cupThermal Dynamics Cutmaster 101My brain
Reply:Maybe increase your pre flow time? Torch might have a leak in it that is contaminating the first few seconds of gas.138# anvilHomebuilt 6 tap kegerator100# cone anvil5" post viceVarious hammers ranging from 250g to 2000gSome tongsA few screwdriversA wrench or twoOh, and a Fronius TPS 2700
Reply:To check if lack of gas coverage at the start is the issue, pull the trigger for a couple sec, quick snip off the end and then weld immediately.  By the way, my brother's mig had problems and it was due to the gun partially pulling out of the connection at the machine.  Same thing happened to another of my friends - is yours tight?Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:I am a fan of these checkers to see what my flow is doing.  I use it on my mig and tig set-ups.  They are cheap and elliminate guess work on good/bad regulators, bad surges at start-up, not enough gas making it to the tip...etc......and they are cheap...Dave J. Attached ImagesDave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Thanks for the tips guys, it really is acting like a lack of gas on start up. I'll double check my connections. I'm not aware of pre-flow on this machine (no obvious adjustment for it anyway) and I get wire instantly when I pull the trigger. Is there supposed to be a delay for a short squirt of gas?I do have a flow meter installed, they are handy for sure.Last edited by AKmud; 01-27-2013 at 12:24 PM.
Reply:When your pressing the Trigger, Listen near the wirefeed, can you hear the click of the gas solenoid opening?? if there is a delay then perhaps your solenoid is sticking? Its easy enough to replace, I had an old hobart set once that this kept happening, had to keep kicking the wire feed to get the gas to start
Reply:Originally Posted by AKmudThanks for the tips guys, it really is acting like a lack of gas on start up. I'll double check my connections. I'm not aware of pre-flow on this machine (no obvious adjustment for it anyway) and I get wire instantly when I pull the trigger. Is there supposed to be a delay for a short squirt of gas?I do have a flow meter installed, they are handy for sure.
Reply:Yep, I have one of those flow checkers, it has come in handy.Something else to check would be the o-rings.138# anvilHomebuilt 6 tap kegerator100# cone anvil5" post viceVarious hammers ranging from 250g to 2000gSome tongsA few screwdriversA wrench or twoOh, and a Fronius TPS 2700
Reply:Keep in mind though, that even if you have flow, the first few seconds may be air and not sheild gas if your line in compromised.- Tim
Reply:Update....I put a new nozzle on and it seems to seal better. I kept my stick out really close today and didn't have as much trouble. All my connections were tight and my gas seems to be flowing ok (I can hear it easily at the gun). I think I'll invest in one of those flow checkers though. This is a new to me machine and I'm just learning all the little nuances of settings tip properly. Yesterday when I was having all the trouble, I was welding some 1/2" and 1/4" stuff which was the thickest I have tried with this rig so far.  Thanks for the tips.
Reply:Originally Posted by tadawsonKeep in mind though, that even if you have flow, the first few seconds may be air and not sheild gas if your line in compromised.- Tim
Reply:Open the drive rolls, hit the trigger 5 to 10 seconds to purge, close the rolls and immediately weld.  If that works fine, you have the problem.- Tim