Flux core weld bead pinholes?

[AIbandit]

What does it mean when your bead has a small hole in it like someone poked it with a needle?

It only happened a couple times and it's always at the side or end of the bead.



Should I even try welding my sheet metal with flux core?

 

[AIbandit]

Got it I know I was moving to fast on the first couple and I didn't wait for it to puddle at the end.

pin holes running flux core:
travel speed to fast
wire speed to fast
fast puddle quenching

flux cored wire needs to have a modest molten puddle to be worked. on thinner materials it is hard to do because of burn through. the pinholes are more than likely from the flux not being boiled out of the molten puddle. this is why flux core wire welds are considered deep penetration welds.

a pause at each lateral change of direction while working the puddle is suggested. the wire out should be slow, maintaining heat and allowing filler metal to flow into puddle.

pin holes will also be a plague if welds are in standing water. guaranteed pin holes throughout the bead.

 

[bails85]

Oi like flux when I'm welding metal that isn't really clean. Its kinda hard to run a bead on sheet metal though. You have to get used to it.

 

[AIbandit]

I'm using a lincoln 180c and it's supposed to be designed for thin sheetmetal but I've read flux is more likely to burn through it.
I'm pretty happy/surprised how clean the beads are coming out with the flux. especially since I haven't welded in 10 years. I think the welder is making up for my shaky non-fluid hands

 

[bails85]

Yeah the flux does burn hotter so it will give holes. Mig is just a lot more controlled. It's easier because you can stitch / pulse weld which you can't do with flux because of the slag. I actually had better luck with the flux when I did some rust repair on my xj. Mig doesn't seem to like dirty part rusted metal at all.

 

[1985xjlaredo]

What wire are you using? Sounds like you could be using a gas shielded flux core wire. You need a self shielding wire if you are not running CO2 or Argon. If you are running gas you could be running too much stick out and not shielding. Could be running to cold and the flux is not boiling out of the bead. Do you have any pics of the welds? I could tell alot by looking at what you are welding on and the Wire manufacturer and model#. I am ASME section IX certified for FCAW/GMAW and SMAW for P-1, P-4, P-5, P-6, P-8, P-10, P-11, and Military grade armor.

 

[xcm]

wait... mig pulse welding? what?

 

[bails85]

Just a bunch of tacking in a row. Pull the trigger let go. Some.get confused when you say stitch welding they assume 1 inch beads along what your welding. So I just say pulse welding.

 

[AIbandit]

I may be wrong but I would consider stitching as short beads and tacking would be tacking.
I tried taking a pic but it didn't show I'm stuck with my phone right now.

It is self shielding wire. I thought all flux core was self shielding, learning something new everyday.

 

[xcm]

Just a bunch of tacking in a row. Pull the trigger let go. Some.get confused when you say stitch welding they assume 1 inch beads along what your welding. So I just say pulse welding.

Thats the ghetto 'tack tack tack' method, mostly used by those who cant weld very well. Stitch welding is as you mention, and i have no idea what your talking about with pulse welding, but thats also not really pulse welding... you cant just redefine technical terms and expect everyone to fallow...

 

[AIbandit]

but thats also not really pulse welding... you cant just redefine technical terms and expect everyone to fallow...

I would fallow you if you made up words!

 

[bails85]

The tack tack tack method works well when you don't want a lot of heat to disperse and warp what you're welding on. Especially sheet metal. A lot of hot rod guys use this method on body parts when they do not want to bond up their car. Also when you are welding if you get your welds too hot it will fatigue the metal and it wont be as strong as it should be. As for pulse I mean just short bursts of welds to create a bead. Not doable with flux because of the self shielding wire that creates slag. I've been to. Fab school and have
welded a lot of things. I'm not the best as it's not my everyday thing but I can get my projects done and they look good.

 

[AIbandit]

I thought they tack it first so it wont warp then weld over it.

 

[bails85]

Most of the time yes. But the method I mentioned works as well. Sheet metal absorbs heat really fast and on thinner gauge it's sometimes impossible not to burn a hole. When I replaced my floor in my xj I used pieces cut out of another xj doner vehicle and welding it was a bitch. Like I said I'm not the best. Sometimes it's just a preference thing. There are times as well when welding tubing that you can't get a solid bead in because of a hard to reach spot so using the stitch/pulse method I mentioned works well.

 

[rockclimber]

I have used the tack tack tack method for thin sheet metal welding.

yes its ghetto, but it works.

its probably the only way to weld sheet metal with flux core... if you want to run a bead, get some gas.

 

[RCP Phx]

Might want to read this,weve got pulse migs at the shop!
http://www.millerwelds.com/pulsedmigprofits/Pulsed_MIG_BenefitsProdPg.pdf

 

[stumpXJ]

Pulse MIG process works great on aluminum too, we use it all the time.

~Stump

 

[1985xjlaredo]

So how is the welding going? Did you figure out that pinhole issue yet?

 

[AIbandit]

None yet I'm going to try some exhaust this weekend.

 

[4WDlifeform]

We use high frequency pulse migs where I work as well, for steel and aluminum. Pretty cool stuff.

The pin holes my be caused by not enough gas. We recently had this problem on a build. Try turning up the gas flow, and be careful that there is no wind or gusts where you are welding. Are you using CO2 or a mixture of argon? I think the 100% CO2 seems to work best with fluxed core wires, at least with the wire were are using.