Mig beads

[Mcgyver]

I finally picked up a nice little 220V mig welder.

whats making me crazy though is the beads. seems no matter what i do a get a big bead proud of the work. I started with Lincolns recommended settings and varied it a bit but not luck. I was in a plant the other day with a robotic mig welder and saw the same thing....most of a semi circle bead sitting proud of the 11 gauge they'd welding.....yet I'm sure I've seen nice flat scallop mig beads before

I had to weld some 1" sq 1/16 tubing the other day. @#$@# the Mig welding; I grabbed the O/A rig....at least with it I can get a good weld that is pretty flat and doesn't take a half a day of messy grinding. Disadvantage though is more heat is pumped into the work so i worry about warp and it takes longer...so I'd rather Mig if i can figure it out

is this just the nature of the beast, or what should look to to get a better result? I'm new at the Mig welding so hopefully its something simple/common/easy to fix that I'm doing wrong

[torker]

If your beads are too ropey...you have too much wire feed for the heat setting...or you are traveling too slow.
If you are pulling the gun...the beads also tend to rope up.
Flatter beads are easier when you push the gun..
Ropey beads (or poor wetting in the edges) can also be caused by welding on cold metal with mickey wire.
Make a pass on cold metal...then run a bead that half overlaps the first and you'll see what i mean. The last bead should always be flatter. It's the heat that helps it flow out.
Also...too much wire stickout will cause ropey welds..

[macona]

Also check your polarity. If the machine was used for flux core it may still be set for that. It will still weld but you will never find a good wire speed/voltage combination to make it run right.

Or are you even running hard wire and gas?

What machine?

Also what size of wire are you running? On what thickness of metal?

[Errol]

Mcgyver, you are exactly where I was some years ago. I just bought a mig welder and experienced the exact same problems.

So I got a millwright friend to come over to give me some pointers. To get as flat as possible surface, here are a couple of things I learned.

Chamfer all your joint edges with grinder prior to welding. Lots of angle.

When welding tubing, like 1" sq x 1/16, and you need a "flat" surface, then leave a bit of a gap between the pieces, then turn up the heat as if you were going to weld 1/8. Then use the contactor in a "stitching" fashion, short burst, move, short burst move and so on... almost like TIG. With some practice, you will get the hang of it.

On verticals, come "down", not up.

And like Torker says, push, rather than pull.

[torker]

Errol...you gotta be really careful "burping" a mickey wire weld.
As long as you have the heat up and are working with light material..it will work.
However...If you are working thicker steel...the chances for cold lap happens everytime you pull the trigger.
Also...mickey wire downhand is ONLY ever used with body work on automobiles.
There is almost no penetration with it.
Even with .045 dualshield running at 28 volts...your still walking on very thin ice when it comes to downhand welds.
Any fab shop I've ever worked in would fire you if you run downhand on anything but chuteing.

[ahidley]

Torker whats "mickey wire."

[camdigger]

Isn't Mickey wire that stuff they use in them Mickey Mouse squirt gun welders???


Kidding (mostly)

[torker]

Isn't Mickey wire that stuff they use in them Mickey Mouse squirt gun welders???


Kidding (mostly)

Sorry..."Mickey Wire"....that's weldor slang for hard wire. Called it that for so long I can't even remember what it's really called.
Russ

[camdigger]

'mig hard wire' aka 'solid core mig wire' aka 'Mickey wire'?

[Errol]

Sorry Mcgyver, wrong info for you. What I relayed to you worked for me to date, but I had no idea these suggestions were ill advised.

Torker, thank you for the additional info. It is a blessing to interact on a forum such as this one to learn and to improve one's skills. And it's also a blessing to have someone so knowledgeable who is willing to take the time to respond and help those of us who can benefit.

Fortunately I can't get fired, because I'm retired, but I can certainly try to change my bad habits. Incidentally, I never "burp" anything over 1/16. If the joint is critical I'll reach for the TIG or O/A.

Also I'll pass your observations back to the fellow that initially gave them to me.