Welding questions

[06switchback]

Ok I'm not a welder its just a hobby / necessity because I'm to cheap to pay someone to do it

I have a Lincoln 255 mig

most of the time my welds look pretty good but lately some weld look good and others are very porous with bubbles and pin holes in them and a lot of times a bubble that I can watch grow while the weld is still hot but after I have let off the trigger and then the next weld looks great what am I doing wrong

It happened to me again today these welds are on the bottom of my bush hog I know they are not the prettiest but will be fine once I hit some rocks they will be ground flat

Any tips advice or ridicule would be appreciated

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[The Cobbler]

by no means an expert welder or even close, but I think you need to clean the metal up ( free of rust)

 

[p_mori7]

you need to clean all that crud off down to bare shiny metal BEFORE doing any welding.

 

[Duker]

I will bypass the critiquing of the welds to those more knowledgeable than myself as I can weld but I am not a welder. I do have the same machine however and I can tell you what issues arise on my machine and maybe your machine has the same trouble.

1.) Unlike my Miller or even my Lincoln MP210 the Power Mig 255 really needs a good ground. I can tell within 2 seconds if I have a bad ground connection. I replaced the ground with a 300 AMP clamp but for some reason it has always been an issue.

2.) I suspect because of the ground issue the surface metal needs to be clean again more so than my other welders. It can be hit or miss on a bead or two where one is fine and the other looks like Fido's **** as Jody would say...
Looking at the pictures I would venture to say a little more grinder/flap wheel prep might help.

3.) Clean wire.. If my Flux wire has been banged around or has some dirt on it from sitting on my shelf under the welder it will have spots where the puddle doesn't flow well.

I don't know if any of this will help but those are issues that have affected the beads on my Power Mig 255.

 

[tarmy]

Clean material, good ground contact near the weld area, enough heat and speed (learned by practice mostly) for the application/penetration...

 

[f150skidoo]

Wormholes in the bead will most of the time come down to contaminated material such as rust, paint, etc. Or not enough gas coverage.


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[Bigblockyeti]

If you're going to weld rusty metal with little or no cleanup, it needs to be SMAW with a 6010 rod.

 

[Doug Arthurs]

I would say more time with the grinder before means less time with the grinder after.

 

[king nero]

What is that even, that you're trying to weld?

 

[06switchback]

I know I didn't spend a lot of time cleaning and grinding on these welds because they are on the bottom of a mower

I did follow all the cracks with an angel grinder to make a v before I welded them I didn't clean the edges

I was welding some cracks in my brush hog its 12 or 14 guage sheet with bracing welded on the top it cracked following the factory welds on the top

The wire should be clean i didn't look at it yesterday but I put the roll on about a month ago its .030 I usually use .035 but bought that by mistake so I'm using it

Thanks for the response

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[TNToy]

Doesn’t matter what you’re welding. If you want it to hold with a MIG, clean everything before you lay a bead

 

[BD1]

As stated, gotta clean that metal and clean for good ground. If welding outside with gas, try protecting the welding area. Gas is blowing away.
That glob in first picture is pulling away as you release trigger. Release trigger and then pull gun away. Good luck.


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[bdbecker]

Dirty base material. All the impurities are boiling out of the puddle while its trying to freeze. I'd definitely grind those out and redo them - those welds will not last long. If you want to avoid this in the future, prep the joint down to bare metal before welding.

 

[Jazz1]

Clean the steel you going to weld will improve your welding whether using flux core or shielding gas. As stated wind will affect gas causing holes or you could be moving too quick. Take your time, you're getting penetration which is critical, not ready for the big time yet.


My boy welding, 12 hour shifts in 45C heat past July. Each weld has to be perfect on boiler tubes,they are x rayed for quality...

 

[Copymutt]

I fought worm holes on a custom exhaust mod for days. Finally realized the soot/ carbon from the inner wall was the cause.

 

[Monza Harry]

I fought worm holes on a custom exhaust mod for days. Finally realized the soot/carbon from the inner wall was the cause.

As mentioned above the other side matters, the paint that I presume is there can catch fire [and the grass on that side]* and draw the air into your puddle with the results you pictured, usually on the same side for me but unwanted air is your enemy on either side. Harry
*And even my coat being on fire didn't help some of my welds, we know these things from,... we'll call it "experience"!

 

[sberry]

That looks pretty good considering the rust.

 

[06switchback]

Maybe you guys were right gotta stop being lazy and do some more grinding

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[bdbecker]

Maybe you guys were right gotta stop being lazy and do some more grinding...

Its worth noting that most everyone (myself included) who commented about needing to clean up the joint before welding had to learn that lesson the hard way. Glad you got it sorted out!

 

[Bigblockyeti]

Maybe you guys were right gotta stop being lazy and do some more grinding

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You don't even necessarily need to grind every time, a knotted wire wheel on a angle grinder can clean up some seriously nasty stuff pretty quick in one pass.

 

[bczygan]

A much happier looking weld!

Bill

 

[trashmanssd]

PPPPP, Proper Preparation Prevents Poor Performance.

 

[06switchback]

You don't even necessarily need to grind every time, a knotted wire wheel on a angle grinder can clean up some seriously nasty stuff pretty quick in one pass.

I know i have a couple wire wheels but the grinding wheel was on the grider

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[Iron Beaver]

It was a revelation to me how much better my welds looked after good material prep. I, too, learned that the hard way.

 

[Joemctag]

And while you’re at it you can grind or buff a spot for your ground clamp and just hit that with the spray paint too, after. Rust seriously prevents a good weld, and with SMAW, too. I, too, couldn’t believe your welds could look that clean, considering.

 

[Aviatordave]

I weld a fair amount. I don’t do it professionally but I did go to school for it. Everybody here is spot on. Clean your metal for MIG. Make sure your ground is on bare metal as well. Rust will conduct but not well if it’s flakey and thick. Don’t know if you’re welding inside or outside but if it’s outside, the wind can blow your shielding gas away and produce a crappy weld as well. Looks like you’re on the right track now.

Good luck!


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