Learning MIG

admin

Okay - it has been a bazillion years since I did any stick welding and I never was any good at that.Recently got a Lincoln ProMIG 135.Have been practicing and the following sorry excuses for a weld are the results.MIG using mixed gas, settings D3 and 3/8" stickout, gas at 24#what am I doing wrong? what causes the slag look and pitting?
Reply:Is the polarity set correctly (DCEP)?Are you sure you are getting shielding gas?  Are you welding out in the wind?
Reply:You're getting porosity for sure... What this probably means is that not enough gas is getting to the weld puddle to protect it from the atmosphere...1) Where is your regulator set? You might want to turn it up some. 2) Like JD mentioned above, youre not anyplace windy when you're welding are you? The wind can just blow your gas away.3) How clean is your metal before you weld it? If theres oil, etc on it, that will cause porosity as well...[Account Abandoned 8/8/16 Please Do Not Attempt Contact Or Expect A Reply]. See you on YouTube! -ChuckE2009
Reply:Ah-HA! Yes, the garage door was open and this is post Irene - the winds aren't bad but I was getting gusts.Yes, I did clean the metal - used a abrasive wheel.I'll try again with the door closedthanks for the input!
Reply:Round 2 - garage door shut.  I know I have good heat as the metal glows red around the weld when I lift the gun.  I tried various lengths of stickout.  I'm going to call my neighbor's cousin who runs Rudy's Welding and Ber (not kidding you either) and see if I can pay him to look over my shoulder and tell me what is wrong (likely me)
Reply:Originally Posted by HackDudeRound 2 - garage door shut.  I know I have good heat as the metal glows red around the weld when I lift the gun.  I tried various lengths of stickout.  I'm going to call my neighbor's cousin who runs Rudy's Welding and Ber (not kidding you either) and see if I can pay him to look over my shoulder and tell me what is wrong (likely me)
Reply:Originally Posted by karuI am by all means a beginner but this is my experience.I started learning mig welding a couple of months back. First day, my welds looked exactly the same. I had not pushed the cable from gun assembly enough into the machine and the air passage (from machine to the gun assembly) was blocked. After a great deal of trouble to find what was happening, finally corrected it.See if you are getting the gas at the gun. I even used soap water to check it to make sure.
Reply:Does gas at 24# mean the same as 24 cfh?  Looks like classic gas coverage issues.I'm not sure what gun comes with that welder but you should be able to use 25 cfh with no problem and in fact go up to 35 cfh (typically a waste of gas).The 'flow gauges" are calibrated across an known orifice, but just because they say 25 cfh, doesn't mean that is what the flow is.  It assuming there is very little resistance in the gun/cable.If you are trying to use a pressure regulator that is not calibrated for flow, you are on your own.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Ya - 25 CFH not # - I'm too used to a standard pressure gauge this is the regulator that came with the unit from Lincoln.I've spent the last hour or so researching and all the common wisdom says gas flow.  So tomorrow night I'm taking the welder apart and reassembling it
Reply:What type of wire are you using in the machine?Minus the slag, the weld beads look like flux core..Miller XMT-3502 Lincoln Power Mig 140C (One w/ dedicated spoolgun)Jackson NexGen / Miller Digital EliteMiller S32P SuperWeldcraft 17fv & 9fv Tig TorchVictor & Purox O/ALincoln Ranger 9Fairly Cold Beer!!
Reply:I'll guess that the polarity isn't set for solid wire/gas, or that there's a lack of gas flow at the nozzle.
Reply:just discovered that the gas was not set on CFH... is was LPH! duh!Last edited by HackDude; 08-31-2011 at 08:19 PM.
Reply:Is the welder plugged straight into the outlet or are you using an extension cord?  An extension cord can cause voltage issues.  Just something else to check
Reply:Originally Posted by zerepenerIs the welder plugged straight into the outlet or are you using an extension cord?  An extension cord can cause voltage issues.  Just something else to check
Reply:looks like the polarity on the welder is backwards.  no way you should need 24CF of flow heck i weld in the shop with the door open all day all the time and rarely have an issue and I run my flow at about 10.  wind will effect it but not your problem I dont believe1 are you using solid wire or flux core?2 are you using 75/25 argon/co2gas3 is your polarity set correctly for your wire.  (I think this is your problem)       If you can feel and hear the gas coming out of the torch when you press the trigger thats not whats causing this issue right nowHypertherm PM 1000 on a CNC TableMiller Maxtron 450 - S52A series feederHobart Handler Lincoln 155 (my sons he's 11)looking to sell or Trade a RFC-23A foot pedalCustom diesel parts fabricator
Reply:The polarity is right and the wire is new - gas is 75/25Turns out I had WAY too much gas - was reading the wrong gauge dial - had liters vs CF.  I've got a good bead now.  thanks for all the help! standby for the next problem (whatever that may be)