switched gas - now welds are porous?

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I am using a MIG with ER70s-6 copper coated wire. Today I switched from a tri-mix gas to a 25/75% argon/co2 and the porosity of my welds are horrible. Any tips on how to make them good again? Should I take the gas back and tell the guy it is bad (bought it from a new place today)? Thanks!My $120 Mig - Harbor Freight 151T 220VMy $300 Plasma Cutter - Rattler 40A  110V/220VCurrent project (Miata Trailer):http://www.lightweightmiata.com/trailer/
Reply:Why were you using Trimix.  give us more information and we can help you.  C-25 is the correct gas, so something else is not correct.  JohnSMAW,GMAW,FCAW,GTAW,SAW,PAC/PAW/OFCand Shielding Gases.  There all here. :
Reply:What is your flow rate?DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:When you've eliminated all other possibilities, consider that the new gas tank you're using may be contaminated with moisture.  But check your gas flow rate, and for leaks between the tank and the mig gun first.
Reply:Originally Posted by weldgaultWhy were you using Trimix.  give us more information and we can help you.  C-25 is the correct gas, so something else is not correct.  John
Reply:The LWS man didn't know what he was talking about.  Ask us here, when you are not sure.  Set the flo-meter on 20 (if you are inside).  Set the voltage in the center and run the wire feed to fast, so it will hit against sound metal, then let off the feed until you get the buzz and that should be the correct setting.  About 3/8 ESO.  Need more, let me know.  JohnSMAW,GMAW,FCAW,GTAW,SAW,PAC/PAW/OFCand Shielding Gases.  There all here. :
Reply:I am going with the simple answer, you got a bad bottle.Disclaimer; "I am just an a$$hole welder, don't take it personally ."
Reply:Originally Posted by TozziWeldingI am going with the simple answer, you got a bad bottle.
Reply:Settings are a little different with a different gas.  Can you adjust the voltage or is it tapped?DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Did you check the hose at the feeder itself going into the solinoid I have knocked those off before.or check for a plugged diffuser?If it's too . get an office jobLincoln wp225g7 Lincoln 250 idealarcFrankenstein O/A set-up Weld-tech  tig set-upLincoln sp 175 plus profax  arc gouger
Reply:also check your diffuser you could have something clogging it.
Reply:You could also try as low as 15 cfh because too much can cause turbulence and induce oxygen into the weld.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Took the bottle back today and got a replacement. Still no good welds (I'll snap some pictures today). I guess I need to start playing with my settings and see what I come up with. Everyone gave me some good tips on here and it will take a while to try all of them. Thanks!My $120 Mig - Harbor Freight 151T 220VMy $300 Plasma Cutter - Rattler 40A  110V/220VCurrent project (Miata Trailer):http://www.lightweightmiata.com/trailer/
Reply:Originally Posted by David RSettings are a little different with a different gas.  Can you adjust the voltage or is it tapped?David
Reply:4 heat settings means tapped.  Try to vary your wire speed just a little from what it was with the other gas.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Originally Posted by David R4 heat settings means tapped.  Try to vary your wire speed just a little from what it was with the other gas.David
Reply:Nope, everything crappy again (after 30 minutes of good welds). No idea what is going on...My $120 Mig - Harbor Freight 151T 220VMy $300 Plasma Cutter - Rattler 40A  110V/220VCurrent project (Miata Trailer):http://www.lightweightmiata.com/trailer/
Reply:Can you go back to the set-up that you were using with the Ar-CO2-O2 blend? I mean exactly and see if it welds good again.....There may be a coincidence of changing shielding gas and something else failing at the same time. Good welds then back to crappy on the same bottle makes me suspect of equipment........just my .02Yeah, yeah, I know you are a weldor too. But, are you a good one?
Reply:Originally Posted by ironkenCan you go back to the set-up that you were using with the Ar-CO2-O2 blend? I mean exactly and see if it welds good again.....There may be a coincidence of changing shielding gas and something else failing at the same time. Good welds then back to crappy on the same bottle makes me suspect of equipment........just my .02
Reply:Your porosity issue suggest a gas flow problem, though.  Is it possible that the solenoid that controls gas flow is sticking?  Or how about a valve in the regulator/flow meter on your welding rig?When it doubt, and when all else fails, change one thing at a time until the problem dissappears...
Reply:Just a tip. Always crack the valve (then close) on a new tank to blow out any dirt, etc. before attaching a regulator.Miller MaxStar 150 STHTIG Advice From Co-Worker - "Just don't burn a hole so big I can't fill it."
Reply:Originally Posted by A_DAB_will_doYour porosity issue suggest a gas flow problem, though.
Reply:Originally Posted by OldgeezerJust a tip. Always crack the valve (then close) on a new tank to blow out any dirt, etc. before attaching a regulator.
Reply:As promised, a picture of the bad welds. The top weld was made a minute before the weld on the side was done. No settings were changed. There was a large gap on the side weld and it wasn't a critical weld so not much care was made to make it "nice".My $120 Mig - Harbor Freight 151T 220VMy $300 Plasma Cutter - Rattler 40A  110V/220VCurrent project (Miata Trailer):http://www.lightweightmiata.com/trailer/
Reply:Ummm, Try a flat weld on plate and see how it goes.    Please post another pic.You may have more than a gas problem.DavidReal world weldin.  When I grow up I want to be a tig weldor.I had a similar problem awhile back. Turned out to be that my gun lead had a small hole it it and it was drawing in air. Caused all kinds of porosity. Also I have heard of this when someone has pulled on the gun to move the welder and the lead pulled out of it holder a little. You might want to take off the lead and check the O rings and make sure the lead is still in good shape.I know when this happened to me it drove me crazy for a little while. It's when I found this site looking for help that I got it fixed.Here is a link to the post I made when I had problems. You might find it a helpful read.http://www.weldingweb.com/vbb/showthread...light=porosityGood luckLast edited by jamlit; 03-05-2008 at 11:48 AM.Miller DVI2Lincoln Precision Tig 225Thermodynamics Cutmaster 38Everything else needed.
Reply:If changing your wire speed made a difference and then it became eratic, maybe you have a kinked liner. Dove me crazy the first time I had one. I have it happen from time to time. The guys in the shop push the mig out of the way and end up jaming it into the wall to get just a little more space. Usually kinks within a foot of the machine. pull the liner out and see if you see any abrupt changes near where it enters the machine.
Reply:I had my wife watch my wire spool yesterday. She said that the wire spool wasn't turning smoothly. I don't know if that means it was binding somewhere or if that means the heat wasn't constant (or something) and the weld was actually causing it to speed up and slow down. Just pressing the trigger while not welding (cup out in the air) causes the wire to very smoothly flow. I will order a new spool of wire just in case it is binding up for some reason. I use 2 pound spools and this one is about out.My $120 Mig - Harbor Freight 151T 220VMy $300 Plasma Cutter - Rattler 40A  110V/220VCurrent project (Miata Trailer):http://www.lightweightmiata.com/trailer/
Reply:Did you set the wire feed roller pressure properly? Disconnect the ground clamp so it isn't grounded against anything, and then point the gun tip at an ungrounded metal plate, tipping the top of the torche to the right or left about 20deg. Then hit the trigger. The wire should come out and form a curl and feed smoothly. If it doesn't, increase the roller pressure control a bit more. If you over-do it though and the wire sticks at some point, you'll get a birdsnest in the feeder so just enough pressure to feed evenly is the key.
Reply:check your diffuser if its clean then you have a wind issue. are you smuthering the nossle on the weld because you need about 1/2 - 3/4 stick out.  and wire speed shouldnt have to do with gas coverage.  you get perosity from O2 not the wire.  do you have a vent or something sucking the smoke out of the area or a fan on?  and try different gun angle (push pull straight up)  try those ideas.
Reply:The kinked liner will do exactly what you are describing if it is just a small kink. If the lead is sort of straight it will seem to run wire fine but as you move around to weld and the liner bends some more, the wire will bind in the liner. Check your wire tension first. If its fine and the feed is eratic, like I said above check your linerfor a kink.
Reply:Also, if you are just about at the end of a spool, especially on the small diameter spools, the wire doesn't always feed out smoothly as you near the end of the spool.  Annoying and a bit of a waste, but you pretty much just have to change to a new spool of wire.And also remember that you could have multiple 'bad' things going on at the same time!Maybe you have a dirty kinked liner that isn't snugged into the torch handle well, and also have a nicked o-ring at the torch cable connection to the machine and a small crack and a few small pin-holes in the cable as well, and also you are near the end of a small diameter spool of wire, and your drive roller tension isn't quite set right, and you had the wrong diameter torch tip in the gun (0.030 tip and 0.025 wire, for instance), and you had a loose wire connection in the machine, and you have a bad work-lead (the 'ground' clamp/wire) connection and crud on the gas diffuser.    Check them all, one at a time, and then try again.
Reply:OK, I figured out what the problem was BUT I am still screwed.The problem was caused by gas - we all knew that. If I turned off the machine and squeezed the trigger I could hear gas coming out. What I didn't realize was that some how the contacts for the wire feed / heat was being met before the pushbutton for the gas flow was met. SO, if the machine was off and I squeezed the trigger all the way down I was getting gas. When I welded I wasn't squeezing the trigger completely so I was only getting sporadic gas flow. I opened up the trigger mech and fixed the problem. I was also having a wire feed problem. Well, 2 minutes after fixing the gas problem the wire stopped feeding and got completely bound up in the sheath. Now I am stuck trying to get another torch/cable setup to replace the one that I completely screwed up trying to fix it. ARGGG!My $120 Mig - Harbor Freight 151T 220VMy $300 Plasma Cutter - Rattler 40A  110V/220VCurrent project (Miata Trailer):http://www.lightweightmiata.com/trailer/
Reply:in the sheath? i am not sure what that is.If you are taking about the gun you can just pull the liner out and not have to buy a whole new gun.They are all a little differant on how they come apart but raed your manual and it should tell you how to change liners.If it's too . get an office jobLincoln wp225g7 Lincoln 250 idealarcFrankenstein O/A set-up Weld-tech  tig set-upLincoln sp 175 plus profax  arc gouger
Reply:rmcelwee I have a 151 that I learned with. The gas valve in our gun is a small plastic valve that should depress slightly before the metal tab connects to apply voltage and wire advancement. Its a cheap setup, for what the welders cost its not a bad deal. I have ran atleast 20 10# rolls of flux core, after I made an adapter for the larger rolls. Some time back I had to take the handle apart, clean the dust out and slightly adjust the tab that makes the voltage connection. What part of the country are you located?I also had troubles of the sort you refered to. At whits end I finally looked at the tip I was using. It had worn a small grove to one side. replacing the tip helped, the best fix was after using a caliper to measure the wire I found that when using the HF wire and Lincon tips from the hardware store, I would drop 1 size tip. The .030 tips fit snug on the .035 wire. I know this isnt right but it worked for me. Good luck with the fix. I think your project looks great, always enjoy looking at project pics.Note to self.......The jacket in the avatar pic is Not for welding....EVER
Reply:Well I had a really long reply and my cat just walked on my keyboard and deleted it! So here is the short version:1) I fixed the porosity problem by bending the contacts in the trigger. Now the gas comes on at 5% trigger depression but the arc/feed doesn't start until 10% trigger depression. No more welds without gas!2) I found where the wire was stuck in the liner and fixed it by cutting an inch off the liner where the wire was stuck. This made the liner shorter than all the other wires/hoses in my torch (not sure of the name of the 6' long bundle of stuff going to the trigger). This shortness made the liner tend to get pulled away from the feed wheel and this caused a misalignment and the wire kept getting bent and bound up right at the beginning of the liner. I made some adjustments last night but it was getting too late to test them. I should know more this morning.3) I am using a 20# spool with a large hole in the middle vs the 2# spools with small hole I have been using. I need to make an adapter to further help with wire feed issues. I bought an adapter that works for a Miller some time ago but it doesn't quite fit my HF Chicago Electric welder.4) This thread really needs some pictures .5) I live in Moncks Corner, SC (close to the Charleston area).My $120 Mig - Harbor Freight 151T 220VMy $300 Plasma Cutter - Rattler 40A  110V/220VCurrent project (Miata Trailer):http://www.lightweightmiata.com/trailer/
Reply:I wish I had the welder inside but its outside loked up in the tool box. I am not sure on the 20# spool you are using as mine are 10 or 11 lb spools. I bought the Lincon spool adapter at H.Depot. Its been several years now but I belive I used the adapter as is, it was just that the door would not close all the way. All I did was cut like 1/2" off the machine side, retained the factory spring and locknut. The only trouble I have had is the spool is large and the case is small making it tough to thread the wire. Well SC is a little far away, If you were still having troubles I was going to offer the use of my lead and torch. Since hopefully within the next week I will have a new lead and torch for this machine. Nothing wrong with the old one other then its short.Good Luck and always glad to see updated pics.Note to self.......The jacket in the avatar pic is Not for welding....EVER