mig and flux core tips and techniques, equipment, filler metal
Poland308
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    Thu Sep 10, 2015 8:45 pm
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    Iowa

If you want to get rid of smoke but have less gas issues then set up the fan to blow away. So it’s sucking the fumes away not pushing them.
I have more questions than answers

Josh
tweake
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    Mon Dec 18, 2017 4:53 am
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    New Zealand

leanangle wrote:Hey all, brand-new welder here. Not really qualified to be handing out advice, but since I had this same problem recently and think I have it figured out, I thought I'd chime in. I've only been able to find this question asked two places in all of the internet, with no definitive answer, so hopefully this helps someone in the future. I'd also appreciate input anyone might have regarding the root (pun totally intended) cause of the observed behavior.

In my case, my first-ever stringer beads had plenty of problems, but slag coverage wasn't one of them. That changed, however, in the next couple days of practice. As everything else about my beads got better, the slag coverage issues got worse. I experimented with every parameter I could, to no avail. Then I realized that the one thing different between my first-ever beads and my nose-to-the-grindstone practice is that I set up a fan blowing across the work to keep me from breathing in the fumes! So I turned off the fan, and whatdayaknow... no more slag coverage problems. Now, without a fan, I notice that the only times there's a break in my slag is in spots where the wind temporarily kicks up, and can predict where the breaks will occur based on that. I'm guessing maybe the reason the op & others are having this problem only in flat position is that in vertical, the work itself is shielding the weld from the wind?

I guess (this is the part where I'd love to hear what y'all think), the cause is either (or both): The wind physically blowing off the compounds that would otherwise cool & solidify over the surface of the weld, or the weld cooling too quick to allow the same compounds to bubble up to the surface. Does either make sense?
awesome :D
tweak it until it breaks
Gdarc21
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    Wed Aug 04, 2021 6:44 am

That certainly adds weight to why the Tee joint works. Flux core is like chasing electrical gremlins.
But when using a new brand check to make its not dualshield, as in needs gas aswell. The 71T and 81ni and I use building stuff needs both. And the 71T I use at home doesnt. All when new to them it helps to run it hot as and bring it down till its mint. As opposed to solid core goin up in heat to find a sweet spot. It finds its happy quicker is all. I use 300- 500dollar 15kg rolls at work and cheapo stuff at home it all looks good just gotta learn how to rub it right.
Flux can get trapped under weld if wire speed is too much and Volts are not enough. Id guess there may be some slag pockets in there somewhere. flux is slag and gas, so sometime slag will hide under weld and gas will escape after weld solidifies. It looks like wormcraters or even dropout on verticals. Turning volts up half a volt or wire speed down a little at a time helps heaps. Torch angle pull at roughly 5 - 10 degree for root run and push at 0- 10 degrees for cap runs. Root runs pull except horizontal butt 10 - 15 degree quick shuffle push works gold. If your spatter looks like that then there may be contamination in weld, flux will be forgiving on not clean stuff but dont knowinly go dirty. Grinder clean is fine. Hand speed matters too but thats a personal variable sometimes someone settings work great for them but for you its a little out. I apologise for writing a 'book' on an old post but there is just not as much flux love and chat out there in WWW land as the other processes. I guess it all the variables that constantly change. It can be hosing with weldmetal somedays. Heat control is literally 70 percent success and the rest can be dodged with handspeed.
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