At wits end on MIG and Porosity

admin

I have a Hobart 210 Ironman.  I am using 25/75 gas, and for some reason I get porosity that resembles coral.  This happens on tube and plate.  All surfaces are ground down to clean metal.  I can weld one joint no problem, and the next one will start out with porosity.  I was trying to build a bumper this weekend, and finally broke out the TA 185, and finished it off with 6010's.I can hear gas coming out of the nozzle, and there is no wind at all.  I even tried maxing out the gas flow but that didn't help. This happens with all rolls of wire.  At this point, I will try anything!!!!
Reply:From what I've read over the last 5 months or so the most common problem that can cause this is a faulty regulator or gas connection. So if you are sure the gas is coming out, it could be a faulty regulator not feeding the right amount of gas. There's a case just like yours where it works fine for awhile then stops on the Miller forum. He replaced the regulator and everything works fine.Disclaimer: I'm not an experienced welder. I just read a lot.
Reply:thanks mercdv.  I calling Hobart tomorrow, and see what they have to say about it, and hopefully warranty the regulator.
Reply:Before you call Hobart:soap and leak check all connections and the regulator as wellLOOK inside machine at gas hose connection to the torch. Those sometimescome loose.If possible, look at the gas hose connections to the gas solenoidBlackbird
Reply:thanks mercdv.  I calling Hobart tomorrow, and see what they have to say about it, and hopefully warranty the regulator.
Reply:I'll do that right now Dave.Thanks.
Reply:Tortis you might give a little more info on your setup, like is the the welding apprattus new, lightly used or unkown and some parameters like type and size of wire, stick out length, what position of weld and please clarify the gas 25/75 or 75/25? Not to make it more difficult for you just easier for usin's. One of your statements said you max'd the gas flow. I would go with Hobarts recommendations and even they gan be sometimes high but it is a good starting point. High gas flow rates can introduce turbulence and bring in air which will create crater like porosity. I assume polarity is correct? The fact that the condition comes and goes seems to indicate a regulator problem. If the equipment is well used the regulator can be a problem, borrow a regulator from someone and switch it out. Some folks hammer the regulator when they turn them on and may not blow out the tank prior to mounting the regulator which may shoot contamination into the reg. Hope it helps.
Reply:I found a small leak where the reg screws into the tank, and tightened it.Now, I pulled the nozzle off, and soaped down the  four holes where the gas comes out of the gun.  At 15 CFM gas was coming out of only one hole.  I jacked it up to 50 CFM, and gas would sometimes come out of two holes, and another squeeze of the trigger it would come out of three, maybe four holes.Sounds like a reg problem to me.Thanks Dave for the soaping idea.
Reply:Have you confirmed that your polarity is correct????  Right out of the box, most of the Hobart and Miller machines are set up for flux core wire.  You need to change the polarity to switch to MIG.Come try it out and stay a while.
Reply:Originally Posted by wielroTortis you might give a little more info on your setup, like is the the welding apprattus new, lightly used or unkown and some parameters like type and size of wire, stick out length, what position of weld and please clarify the gas 25/75 or 75/25? Not to make it more difficult for you just easier for usin's. One of your statements said you max'd the gas flow. I would go with Hobarts recommendations and even they gan be sometimes high but it is a good starting point. High gas flow rates can introduce turbulence and bring in air which will create crater like porosity. I assume polarity is correct? The fact that the condition comes and goes seems to indicate a regulator problem. If the equipment is well used the regulator can be a problem, borrow a regulator from someone and switch it out. Some folks hammer the regulator when they turn them on and may not blow out the tank prior to mounting the regulator which may shoot contamination into the reg. Hope it helps.
Reply:Originally Posted by tortisI found a small leak where the reg screws into the tank, and tightened it.Now, I pulled the nozzle off, and soaped down the  four holes where the gas comes out of the gun.  At 15 CFM gas was coming out of only one hole.  I jacked it up to 50 CFM, and gas would sometimes come out of two holes, and another squeeze of the trigger it would come out of three, maybe four holes.Sounds like a reg problem to me.Thanks Dave for the soaping idea.
Reply:By all means do what these guys say about testing everything between the regulator and the nozzle. I was just offering the most likely culprit but there are plenty of other things that can cause insufficient gas flow. I suspected the regulator only because it works for awhile then stops but you still want to test everything else just to rule everything else out.These guys know their stuff so check everything down to the O-rings if they suggest it.
Reply:-additionally, if one checks things, you may find you have more than one problem.-unscrew the diffuser and blow some compressed air thru a disconnected torchto help clear out the torch cable housing-Be aware that the amount (if any) stickout of the  contact tip past the nozzle,the position of the nozzle, the type of joint, all can come into play with porosity problems.Blackbird
Reply:always a good idea to crack your valve on tank to blow out any crap. before installing flow meter. any junk going forward will clog and cause problems52, 59 & 66 Lincoln SA200, Tombstone Idealarc 250, Thermal Dynamics Cutmaster 50, Marquette 250 amp mig, Miller 330 A/BP
Reply:Like Dave says..........there's actual stickout, and electrical stickout"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Get another bottle and see if the gas is stale. Yes, it does occasionally happen. All the other advice is good, but if you have gas flow into the cup, you should be OK, even if it's not stellar. I have buried my tip in the dirt, clogged it with spatter horribly, and my gas is set at 15, I never alter it. It will weld ok, even when filthy. It of course welds much better when clean, but it has been known to happen under a truck in the dirt.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:All suggestions to this point are good... A couple more I would suggest:1) Make sure that the end of your Mig Gun is fully seated into the Gun Receiver Bushing of the machine (Next to the drive rolls, where the set screw is to lock it in) to make sure that your gas ports are aligned properly.2) Use an independant flowmeter to test the ACTUAL Volume of shielding gas at the Nozzle - I use one regularly to test the fitness of the system, and to "see" any improvements I have made as I go about my diagnostics for leaks.The flowmeter I use is the ESAB Gas Meter Part # 19043It is a clear plastic tube with a floating ball (much like a regulator mounted flow meter) with a graduation lines on it for different shielding gases... Disconnect the drive rolls, hold the gun with the nozzle vertical, place the Gas Meter over the nozzle, and pull the trigger.  Works for Tig units as well.I rarely pay attention to what the regulator mounted flowmeter reads (When the system is fit and has no leaks) I am only concerned with the actual flow at the nozzle in the weld zone.Good Luck.Oh CRAP - Forgot the simplest advice of all - CLEAN THE INSIDE OF YOUR NOZZLE - Any disruption, or re-direction of Gas FLow may lead to Porosity.Last edited by Black Wolf; 06-02-2010 at 01:00 AM.Later,Jason
Reply:Thanks every one for your input.  I think it may have been an oring where the hose hooks to the machine. I blew out the hose, and a little water on the orings when hooking up the hose to the machine.  It is working fine now.  Thanks again. for the support.
Reply:Sounds good.In the future, keep in mind that nozzle dip works really well to keep O-Rings lubricated, and helps seal up the nozzle to the back end of the diffuser as well.Happy Welding.Later,Jason
Reply:this may be way off bud but I found it to be my problem when had the same issue.  The breaker that I was running the welder off of was just big enough to run it but as soon as I was on the trigger long enough i was loosing juice I guess but it never tripped the breaker.  I put a bigger breaker in and no more issue at all porosity GONE as long as I do my part that is.  just a thought