Dual shield help!

[motolife313]

The ball will stay floating if u have a leak. Sometimes my gas line gets in a kink so you could check over youre gas line. And I’ve had cups go bad and get gas problems like that so replace the cup

[ccs]

So I went out and ground out the worst of those 2 welds:



I turned the gas up to 45 CFH and started welding again and partway up I noticed my stickout was a lot more than I thought it was so I tightened it up.
I'm guessing that long stickout led to the small amount of porosity in this weld, it's about the right spot.



I got myself in a better position to see my stickout and welded the rest of the joint:



So I'm thinking the issue was likely not enough gas flow coupled with a bad job of holding the proper stickout, just making the problem worse. Sound reasonable to you guys?
You guys hit the nail on the head, lack of gas coverage. I fight to keep myself from getting tight on the metal as I would for hardwire, I guess I was way overdoing it.
Thanks again for all your help!

[smithdoor]

Try 1/2" stickout.
Are use a cup for fluxcore or mig?

Dave

So I went out and ground out the worst of those 2 welds:



I turned the gas up to 45 CFH and started welding again and partway up I noticed my stickout was a lot more than I thought it was so I tightened it up.
I'm guessing that long stickout led to the small amount of porosity in this weld, it's about the right spot.



I got myself in a better position to see my stickout and welded the rest of the joint:



So I'm thinking the issue was likely not enough gas flow coupled with a bad job of holding the proper stickout, just making the problem worse. Sound reasonable to you guys?
You guys hit the nail on the head, lack of gas coverage. I fight to keep myself from getting tight on the metal as I would for hardwire, I guess I was way overdoing it.
Thanks again for all your help!

[motolife313]

You can make a dual shield weld with almost no gas. The weld rubs hotter with lack of gas and looks brighter in the mask.

[MetalMan23]

The ball will stay floating if u have a leak. Sometimes my gas line gets in a kink so you could check over youre gas line. And I’ve had cups go bad and get gas problems like that so replace the cup

Not if the leak is after the gas valve, like it was in my case.

Sent from my fab shop using a mig welder and a grinder

[motolife313]

Valve in the wire feeder machine?

[djd775]

Try 1/2" stickout.
Are use a cup for fluxcore or mig?

Dave

Is that black pipe? I know you’ve cleaned the weld area but I’ve had experience with porosity in dual shield due to impurities in the lap joint. The crap gets hot and boils out through the bead. Seems the flux puddle doesn’t let it gas off ahead of the bead like solid wire does. Looks just like your pictures. You said it doesn’t make sense that your test bead on scrap was good….I agree. And I wonder if your first bead (that you ground out) boiled most if the crap out so you had a cleaner pass on the second attempt.


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[ccs]

It's actually just 4.5" pipe, i didn't take off all of the millscale though. You may be right though, dunno. I thought dual shield was supposed to be good at burning out impurities vs hardwire. Doesn't seem so though, I could be welding directly on paint w/ hardwire and not get a small fraction of the porosity as I got on these welds.

[smithdoor]

Dual shield does shielding gas or you get porosity.
They make cups for Dual shield wire they longer than solid wire cups as you need a longer stick out for flux to work. But same time you still need shielding gas .

Dave

It's actually just 4.5" pipe, i didn't take off all of the millscale though. You may be right though, dunno. I thought dual shield was supposed to be good at burning out impurities vs hardwire. Doesn't seem so though, I could be welding directly on paint w/ hardwire and not get a small fraction of the porosity as I got on these welds.

[djd775]

It's actually just 4.5" pipe, i didn't take off all of the millscale though. You may be right though, dunno. I thought dual shield was supposed to be good at burning out impurities vs hardwire. Doesn't seem so though, I could be welding directly on paint w/ hardwire and not get a small fraction of the porosity as I got on these welds.

In my experience, dual shield is much more sensitive to impurities than hardwire is.


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[Willie B]

When Dual shield works well it's wonderful! When it doesn't, it is not a good day.

My experience is limited, usually it's MIG or stick for steel.

My first attempt was misery! Porosity ranged from your variety to worm tracks under the flux. I was in Maine Oxy one day, complained about it, I was informed I had a mismatch of gas & wire. Wire I was using was for 85/15 gas, I was using 75/25.

New wire, I had birdnest problems at the feed rollers. At wits end, I discovered a "jump liner" that came with my 400 amp Bernard gun. 16?" liner smaller diameter, it fits as a replacement for the end of the long liner. I also added some felt pads with lube they sold me at Maine Oxy.

Ultimately, I finished my projects.

Gas coverage is everything with Dual Shield. Any breeze will blow air into the cloud. Too much gas flow or too little gets air into the weld.

In my case, Oscar suggested a longer nozzle. Bernard is difficult as they don't offer part numbers that'll fit.

[MetalMan23]

In my experience, dual shield is much more sensitive to impurities than hardwire is.


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I found the same thing

Sent from my fab shop using a mig welder and a grinder

[smithdoor]

Dual shield just show operator errors faster.

Dual shield when everything is right the flux fall off.

Dave

In my experience, dual shield is much more sensitive to impurities than hardwire is.


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[Willie B]

I don't believe Dual Shield is better at welding over impurities. Rust, mill scale, grease, or paint have to be removed.
Advantage of Dual Shield are more certain fusion, better penetration, nicer running uphill, speed & weld appearance. I don't think it is magic as to welding over junk.

[smithdoor]

Why would weld over Rust, mill scale, grease, or paint . To due job right you need have clean metal with any welding.

Dave

I don't believe Dual Shield is better at welding over impurities. Rust, mill scale, grease, or paint have to be removed.
Advantage of Dual Shield are more certain fusion, better penetration, nicer running uphill, speed & weld appearance. I don't think it is magic as to welding over junk.

[MetalMan23]

Why would weld over Rust, mill scale, grease, or paint . To due job right you need have clean metal with any welding.

Dave

Exactly

Sent from my fab shop using a mig welder and a grinder

[motolife313]

Why would weld over Rust, mill scale, grease, or paint . To due job right you need have clean metal with any welding.

Dave

It will burn right through scale, paint and surface rust. We weld buildings together and don’t have to grind the scale

[smithdoor]

Did say you could not do dirty welding but will NOT get a good weld.

Working on buildings you are holding someone life in your weld.
This type welding is not AG type welding.

Dave

It will burn right through scale, paint and surface rust. We weld buildings together and don’t have to grind the scale

[Willie B]

It will burn right through scale, paint and surface rust. We weld buildings together and don’t have to grind the scale

Maybe it wasn't the planes on September 11, 2001, maybe it was Moto, or somebody like him. Might the buildings have stood if Moto didn't have an attitude?

In written instructions from manufacturers or engineers, can you quote where it says "no need to remove mill scale, rust, grease, or paint" ?

[motolife313]

No you’re just being over sensitive and if it doesn’t spec it on the prints then no need to remove it

[smithdoor]

Most drawings and specs I read said to follow AWS.
Even not indicating AWS the weld needs to be clean.

I would just start doing tomorrow.
I aways have a 4½" grinder by side and a wire brush.

If read the AWS specs it does allow for a light mill scale on some types rod and fluxcore. You do need to know when it applies.

Dave

No you’re just being over sensitive and if it doesn’t spec it on the prints then no need to remove it

[Willie B]

No you’re just being over sensitive and if it doesn’t spec it on the prints then no need to remove it

OK, your welds are prettier than mine, I'll skeptically entertain your opinion. To me, it feels like welding steel means you have to have steel exposed, not gunk.


Nobody in the world is more offended than me about price gets the job, quality does not. If you do a good job, price it as such, some turd fu*ks it up at a lower price, they get the job.

I'm also offended that doing it right is a recipe for financial ruin. I wish America hadn't gone there.

[smithdoor]

I learned about bad welds before I could drafted doing work my father.
My father had go over all welders weld and fix them.
The books at did not cover how to fix bad welds. So I was on my own.

I had bubbles in welds. Cracks in welds and some the materials. I lots of holes to fix.

We did joke about using spackle on welds but I did not. I had to grind the bubbles and cracks out and re-weld the joint and plug to holes ready for paint.

I want money for electronic test equipment and model aircraft.
Great job to have.

The books did cover how to do the welding right.

Dave

PS
I only had 7" grinder, porpane torch and a wire brush and a welder

No you’re just being over sensitive and if it doesn’t spec it on the prints then no need to remove it

[Oscar]

I'd be willing to bet that while doing these initial welds, the first few layers of wire were spent up. Those first layers are the ones that will pick up moisture, especially over long periods of time. Now that those are gone, I bet the rest of the roll will run good, assuming it ends up being used up completely.

[M J D]

Pretty much the same prep for 7018 works for dual shield or inner shield. Mill scale , light rust and small amounts of oil or grease are no problem . Never had porosity issues because of surface prep, rusty dirty wire, that's a whole other issue.