MIG welding problems

[punchdrunk monkey]

There are lots of threads on pretty welds but how about one on bad/problem welds to help teach people what/how to weld right.

Every one in a while my MIG wire will bead up on the tip of the gun. What causes this?

Also, I had a spot where I finished a weld and (lack of better word) a stalagmite grew out of it. I grinded it out and the weld was very pouris (sp?). I'm guessing the weld got cantaminated. Maybe oil on the tube or luck of shielding gas. I used to run straight co2 but I just switched to steel mix and have had this happen more times now than before.

[tmathews]

Just curious... but what is your CFH ? I.e. cubic feet per hour. It should be 25-30. Also, check your gas hose and gun for leaks.

As far as the wire, shorting out at the tip... Check the tension on the wire... You should only have enough to feed the wire.. Any tighter and the wire will get smashed in the drive and go from round to oval.

This could possibly create a feeding problem through the liner and into the diffuser then at the tip.

[atomicjoe23]

I'm with TMathews. . .that porosity is most likely from a lack of cover gas. . .especially with the MIG process. . .and 25-35 CFH (I run 30) is the normal range

What type of gun are you running. . .some of the guns allow you to adjust the location of the contact tip with relation to the torch tip. . .if your contact tip location isn't correct then that can happen to the wire at the tip of the gun. . .I have also running too much WFS (wire feed speed. . .amps) cause that as well. . .

[phansigar0614]

I agree, I've seen a worn liner cause changes in wire speed and result in problems like this. Also, make sure there are no air currents blowing your sheilding gas out of the way. It might be trivial but, here's a list of common problems from the Lincoln Electric website...

http://www.lincolnelectric.com/knowledge/articles/content/gmaw.asp

Hope this helps...

[Giant Geoff]

If we have a problem with mixed gas, we will roll the bottle on the ground for 10-15 minutes. Some bottles have a pick up tube running down the inside that sucks below the half way point, so we mix it on the ground to get it to weld better.

[Chase 2]

If we have a problem with mixed gas, we will roll the bottle on the ground for 10-15 minutes. Some bottles have a pick up tube running down the inside that sucks below the half way point, so we mix it on the ground to get it to weld better.


Yeah, and then you fill your tires with Nitrogen, LOL!!!

[DBMETALWORX]

i'm with tmathews. . .that porosity is most likely from a lack of cover gas. . .especially with the mig process. . .and 25-35 cfh (i run 30) is the normal range

what type of gun are you running. . .some of the guns allow you to adjust the location of the contact tip with relation to the torch tip. . .if your contact tip location isn't correct then that can happen to the wire at the tip of the gun. . .i have also running too much wfs (wire feed speed. . .amps) cause that as well. . .

i run 25 cfh in front of the cooler...with .035 solid wire.. I run 30 cfh, .045 on thick stuff- 1/2"- 1". I also prefer a gun that the tip is even with the end of the gas sheild . When welding 16ga, i run 20 cfh. More arc needs more sheild...

[philofab]

i run 25 cfh in front of the cooler...with .035 solid wire.. I run 30 cfh, .045 on thick stuff- 1/2"- 1". I also prefer a gun that the tip is even with the end of the gas sheild . When welding 16ga, i run 20 cfh. More arc needs more sheild...

What thickness of metal are you welding? I use .030 for most stuff up to 3/16.Anything above that I do in multiple passes. A thinner wire needs more wire speed but creates a nicer puddle and weld. I save the .025 for 16 ga.

[DBMETALWORX]

what thickness of metal are you welding? I use .030 for most stuff up to 3/16.anything above that i do in multiple passes. A thinner wire needs more wire speed but creates a nicer puddle and weld. I save the .025 for 16 ga.

i too , run .025" on 16ga w/20cfh on the gas. I used .030 back in the day, but went to .035, cuz its so much cheaper....030 does make a nice weld on tubing..as far as thickness goes, we weld from 20ga-4", and as thick as 6",, but most of the time it's 1" and less. What kind of 110v machine are you running? Plz tell me it's a miller...

[philofab]

i too , run .025" on 16ga w/20cfh on the gas. I used .030 back in the day, but went to .035, cuz its so much cheaper....030 does make a nice weld on tubing..as far as thickness goes, we weld from 20ga-4", and as thick as 6",, but most of the time it's 1" and less. What kind of 110v machine are you running? Plz tell me it's a miller...

I don't have any 110v machines. I've got a Lincoln 170T, Lincoln 175 plus, Miller 210, and a really old Miller wire feed that needs my forklift to move it.

[DBMETALWORX]

i don't have any 110v machines. I've got a lincoln 170t, lincoln 175 plus, miller 210, and a really old miller wire feed that needs my forklift to move it.

yeah you're pretty well maxed out on 3/16"-1/4" with the lincolns, even though they're both 220v. Your miller 210 should be fine for single pass. I do like the .030" wire, every time start welding tubing, i want some..that old machine, is that 1 with a huge gun?

[atomicjoe23]

I have the Miller 210 as well. . .it's good up to 3/8" steel for single pass. . .although in my opinion, that's pretty thick for single pass MIG. . .not saying it cant' be done (because I have), but. . .

[punchdrunk monkey]

My MIG gun is the stock Miller one. I tried cleaning the parts and then wiping them with brake cleaner and I we still having these things "grow" out on the weld. I've never had this problem before. As I'm thinking about it, I know I just changed wire and bottles when this started happening. Last night I changed the steel mix back to CO2 and the welds are better. I'm guessing I got either a bad batch of steel mix or I need to roll it on the ground like posted before.

As for the weld balling up on the tip of the welder....after doing some research, that is typically caused by lack of wire speed.

[DBMETALWORX]

My MIG gun is the stock Miller one. I tried cleaning the parts and then wiping them with brake cleaner and I we still having these things "grow" out on the weld. I've never had this problem before. As I'm thinking about it, I know I just changed wire and bottles when this started happening. Last night I changed the steel mix back to CO2 and the welds are better. I'm guessing I got either a bad batch of steel mix or I need to roll it on the ground like posted before.

As for the weld balling up on the tip of the welder....after doing some research, that is typically caused by lack of wire speed.

try a little less voltage.. the mix gas is better also. i've never heard of rolling the bottle on the floor..check where your gun goes into the machine, make sure it's all the way in with no cuts on the o-rings. 25cfh is a good starting place for gas flow..

[philofab]

yeah you're pretty well maxed out on 3/16"-1/4" with the lincolns, even though they're both 220v. Your miller 210 should be fine for single pass. I do like the .030" wire, every time start welding tubing, i want some..that old machine, is that 1 with a huge gun?

I was wrong, The MIG is a Lincoln IdealARC SP-200. The old Miller is a TIG, it's been so long since I've used it i forgot what kind it was!

[mikeyfrombc]

man you guys use alot of gas flow do you work in a windy areas ?? i run 15 to 18 cfh on my mig , 75/25 gas . as for porosity in welds most of the issues i,ve seen are reg related or very dirty oily steel , or no gas . i have swapped regs on both my machines due to leaky diaphrams .

[atomicjoe23]

I use 25-30 CFH because that's what I was taught at school. . .and I only just recently got a welder of my own at home so I haven't gone through a cylinder of gas yet (and therefore haven't felt the pain of buying gas yet) and I haven't had the chance to really play with it very much. . .I still have to fine tune my settings on it to get the welds I want. . .after I get the V/A settings tuned I will probably try to see what I can do about turning the gas flow down. . .

. . .I hadn't even really thought about the cost of gas since I've never been the one paying for it before!!! but that's a very good point!

. . .and I have a 211 not a 210. . .brain fart. . .

[DBMETALWORX]

man you guys use alot of gas flow do you work in a windy areas ?? I run 15 to 18 cfh on my mig , 75/25 gas . As for porosity in welds most of the issues i,ve seen are reg related or very dirty oily steel , or no gas . I have swapped regs on both my machines due to leaky diaphrams .

yeah i'm either in front of the cooler or outside..outside i prefer fluxcore, wind doesn't matter.. How thick are you welding @ 15 cfh?

[mikeyfrombc]

yeah i'm either in front of the cooler or outside..outside i prefer fluxcore, wind doesn't matter.. How thick are you welding @ 15 cfh?

no more then 1/4" i bevel and leave gaps as well , most is tube i,m considering going to a .023" wire for the chassis work i do , max tube is .120" , and again i prep every joint i,m a machinist and i deburr every piece i handle force of habit LOL

[atomicjoe23]

no more then 1/4" i bevel and leave gaps as well , most is tube i,m considering going to a .023" wire for the chassis work i do , max tube is .120" , and again i prep every joint i,m a machinist and i deburr every piece i handle force of habit LOL


From personal experience you are doing way too much work for MIG welding tubing. . .

. . .I agree you should deburr and bevel/chamfer the eduges, but you don't need to leave gaps. . .in my experience it's better to have as tight a fit-up as possible when it comes to the tube chassis. . .

. . .in my training for state certification we didn't do gaps until you get to 3/8" and thicker material. . .

[mikeyfrombc]

From personal experience you are doing way too much work for MIG welding tubing. . .

. . .I agree you should deburr and bevel/chamfer the eduges, but you don't need to leave gaps. . .in my experience it's better to have as tight a fit-up as possible when it comes to the tube chassis. . .

. . .in my training for state certification we didn't do gaps until you get to 3/8" and thicker material. . .

we leave gaps on lots of stuff we mig weld at work , the company i work for builds and design horse carriages , and they are used for certain forms of horse racing , they beat the crap out of them crash them into trees , had a few runaway horses flip them and run along with the carriage bouncing on the ground behind it LOL .

we also design build and manufacture tubular a-arms for a customer and all the tubes are coped to leave a gap when in the fixture . IMO this gives you the strongest mig weld , you are assured better penetration with DOM and ERW , on certain parts we have the skin of the item turned .005" smaller to help penetration of the welds , the skin sometimes dosen,t allow the weld to fully penetrate , we discovered this over time . the guys also weld with the machine set really high as they have faster weld movement and don,t burn thru the tubes as easy as i do at the same settings LOL

[atomicjoe23]

As long as it is working for you then "all systems are go". . .

. . .as long as you get full penetration and fusion, and don't have cold-lap or undercut then anything after that is simply style and visual appeal (as long as you don't have a huge mound of filler metal at the joint to act as a stress riser). . .

[indirtwetrust]

I was recently having a lot of issues with my mig, it would weld good then bad back and forth, boogers in the middle of the bead and it just wouldn't fine tune anymore. It wasn't until the welder quit feeding all together, when I replaced the circuit board, that I realized that the potensiometer or whatever the component is on the board that controls the wire speed was failing. After dealing with that awfull welding for a week it feels like a new machine. I know your problem sounds more like gas but something to keep in mind.