Flux-Cored Welding Basics: Tips for Flux-Cored Welding

Flux-Cored Welding Basics: Tips for Flux-Cored Welding


Hi, my name is Joel Ort with Miller
Electric Manufacturing Company. Today we’re going to show you how to weld with
the self-shielded flux core welding process and the flat horizontal vertical
and overhead positions. Unlike the MIG process, flux core welding
does not need a shielding gas. The reason for this is that the wire is hollow and
on the inside of the wire there’s a flux and that will react with the weld pool
which protects the weld pool from contaminants. This makes it the ideal
process for outdoor welding. It’s always a good idea before you start your
project to practice welding on some material that’s similar to what you’re
going to be welding on this way you’ll achieve the results that you want. And
also, before you begin have the proper safety apparel on, such as a jacket, some
safety glasses, long pants, some steel toe boots, a welding helmet, and some welding
gloves. For the drive rolls with flux core
welding, you’re going to want to use the knurled groove
drive rolls, otherwise I will not feed the wire properly if you use the smooth
drive rolls on there. And also for flux core welding you’re going to want to
change your polarity to electrode negative. That’s electrode positive for
MIG welding but for self-shielded flux core you need electrode negative. Flux
core welding produces a lot more smoke than typical milled welding. It’s a good
idea to make sure you have adequate ventilation. If you’re indoors just make
sure you turn on a fan and open a door. The wires stick out should
generally be about 1/2 to 3/4 of an inch from the contact tip, possibly a little
longer for tight joints. Gun travel for flux core varies a little bit
differently. Instead of pushing the gun forward, what you’ll need to do is drag
the gun or backhand weld similar to stick welding. For a typical butt weld or flat position weld,
your gun should be at 90 degrees to your workpiece and
10 degrees tilted back, welding with a slight weave, pausing side to side to
avoid undercut. With flux cored welding, you’re going to
have slag that’s left behind when you’re done with your weld. Different wire types
produce slag with different properties, but either way all of it must be chipped,
scraped, and brushed off completely before you make a second pass or make
multiple passes on thicker material. For a typical t-joint, you’re going to want
the gun at 45 degrees or an equal distance from each piece and on thicker
pieces you may want to weave the gun pausing on each side to avoid undercut. For a lap joint, you’re going to want
your gun at 60 to 70 degrees directing most of the heat toward the bottom of
the workpiece and make one straight weld. For the typical horizontal weld position,
the first thing you’ll want to do is turn your welding parameters on your
machine down about ten to fifteen percent. You also want to angle your gun
upwards towards the weld puddle at around ten degrees to accommodate for
gravity. For the vertical welding position, again you’ll want to turn your
machine parameters down by ten to fifteen percent. You want to angle your
gun at five to fifteen degrees up at the at the weld puddle. You’re going to want
to weave from side to side, pausing on the edges to avoid undercut. And also
with vertical welding, you can world weld vertical up or vertical down. Vertical
down will give you less penetration and is much better for thinner metals.
Vertical up will give you more penetration for anything a quarter inch
or above in thickness. The overhead welding position is the most difficult to do. Try
to avoid it if you can, but if you need to, again you’ll need to reduce your per
welding parameters a minimum of ten to fifteen percent.
Try to maintain fast travel speeds and then you can avoid having the weld pool
fall from the joint and on to you. Self-shielded flux core welding is a great
process to learn. It enables you to weld outside and you don’t have to worry
about your shielding gas blowing away. But like any other type of welding, a lot
of practice and some patience will go a long way to making a good quality weld.

100 thoughts on “Flux-Cored Welding Basics: Tips for Flux-Cored Welding

  1. No problem I am a student currently enrolled in a welding program if you have other questions I'll aid you to the best of my knowledge.

  2. It's not that the flux core dont need a shield gas, but the gas is being released within the core of the wire(flux core), so you might want a welder tip for shielding aswell.

  3. Hi Joel, I've noticed that some people take off the gas shield when using flux cored wire. I can see why this is possible because you aren't using a gas. My question is ,'Would this be OK do you think for 'any' torch as I can see how much better you can see your work. Great Vids for green people like me .Thanks a lot.

  4. Joel…thank you for a great video. An experienced welder at work named Al Howie recently explained to me that the gas shield nozzle my welder came with is not good for flux core wire. I'm going to remove it and try again. All I was getting was splatter and blobs of weld. I'm better with stick, so this has been frustrating for me. Thanks to for going into detail on angles, stitches, drags and positions. Deuce? I own a real Deuce. That would be an M35A2C. Peace.

  5. Thanks for answering my previous question. Another newbie question is how safe is electric flux corded welder? Let's say I accidentally exposed and touched the piece of metal while welding, would I get electrocuted and die on the spot? Example 100 amp welder. I'm in fl with 90+ degree everyday, so by the time I'm done wearing full protection suit, I'd sweats a lot and it's create moisture which I heard it's not good for welding.

  6. I want to learn to weld badly my coworker let me practice with his stick welder, but that is not the simplest thing for a beginner although I did weld what i need to. It was ugly but it held. This flux core welding looks better to me because there's morse control with the hands. 

  7. Holy cow, I've been welding as a hobby on and off since I was in high school (about 4 years ago) and never new you were supposed to pull the weld with flux cored. I always ran mine like a conventional MIG welder. Thanks for the tips, time to go fabricate!

  8. What was that blue plastic/mylar sheet on the back of the bench? is that purely a light shield or does it also prevent shots of sparks and metal? Where is it avail?

  9. Thank You for taking the time to make this video. Guys like me appreciate it as I have many welding needs around my place and can't afford a welder's time. With this video, I am far less intimidated with the thought of trying it out. I came across about 100 pounds of welding wire in an estate sale. Now, I know what to do with it. Thanks again.

  10. do you think the $100 mig/flux from harbor freight would be good for a first time welder and for weekend projects like small auto welds or go karts etc? 

  11. Firstl, even though there is a flux, the weld is much better if you use Argon CO2 gas too. Secondly, you need a shroud on your gun too. Again the weld will be much better.

  12. About the fastest welding method I've ever used.Low current use compared MAW and about 3 times the travel speed. While not the most attractive result certainly tough and pinpoint positioning of heat.

  13. What i have now is a MIG and i really don't want to buy a new flux and gas to weld aluminum. If i use an aluminum wire that's got the flux core could i weld the aluminum?

  14. Totalne nieporozumienie ten drut samosłonowy, dużo odprysków, masa dymu, jeszcze się dusze, pospawać pospawasz, ale jakość mizerna, tupa

  15. Hi! Thanks for video! Why are only flux core machines set DC positive when everything I've read says you need DC Neg to do flux core properly?

  16. I got my Easy MIG 100T/1 from Ebay. This is my first time using welding machine and I have a question. I put the flux core wire included and the motor pulled the wire fine but when I try to start soldering nothing happened. The ground cable is on my metal part and moved the switches to differents position from 1 to 2 and from Min to Max andnothing happened. Can you tell me what is the problem? I hear the motor running. Maybe the ground cable is not conected inside the machine. What I need to do? Thank you in advantage.

  17. Do you need to clean the slag off at the finish? Will it affect the weld over time or even act as a barrier to the elements? The only reason I can think of to deslag is to inspect the weld.

  18. First comment in 7 months, but here goes.
    I bought a Pro-series 125 amp flux-core kit, and it came with a nozzle. Why if it isn't needed? I understand all about shielding gas and flux doesn't require any, I was just curious why they would include a part that's not needed, since my machine is flux only.. Thanks.

  19. Recently bought the Millermatic 125 and am having trouble with it. I have installed the flux core and adjusted the polarity as it specifies in the manual. Also I have tried to ground it on varies metals i had available. Everything appears to be in order but when i go to weld, nothing happens. Only the wire feeds but nothing else. What could i be missing? I've looked over the manual several times with no luck.

  20. I wish 'Miller Welders' re-shoots all their welding videos with a proper camera filter so we can see the puddle and the bead being formed not just the ultra violet rays! The explanation does not suffice and it sounds theoretical without practice. So that being said, will stay neutral, no thumbs up or down.

  21. Not bad. Thanks. But, I would fix the mono audio at the beginning and end. That is no good when listening on headphones (loud work area).

  22. It looked like the tip was much shorter for the 90 degree weld; is that the case? Other videos suggest 1/4"- 3/8". other than extreme lengths does it really matter? Thanks!

  23. Watched this last night, took notes. Today I dropped the cover thingy, held at about 1/2", cleaned shlag before second pass and when I stopped and started again, tuned back the pressure on my wire feed, and turned back my feed rate. It was almost like I remembered how to weld, I was like holy shit there's a decent puddle. Any way it helped me so thanks.

  24. Worked in a rail freight car manufacturing plant for three years. They had flux core, but it was also with combination with argon and CO2, the wire used was called XL-71, that stuff was amazing, so easy to weld in pretty much any position for thicknesses over 1/8 inch. If you get your hands on that stuff, go nuts on structural welding.

  25. how do you create perfect beads like these? mine look like brail! is it because I'm using the wrong wire, not enough heat, not enough wire, what is it?

  26. he said over-head is the most difficult but personally I think vertical up is the most challenging. over-head is easy. I use a gas MIG at work but I'm sure the weld puddle behaves basically the same

  27. Great Video! What kind of amperage, duty cycle, power supply and pwoer output was this machine. I'm in the market for my first machine. Don't have a lot of money to spend though. A few hundred is about all. Not going to be welding anything over 3/8" flat stock to say 3/4" round stock steel.

    Can you suggest a good starter a machine. I'm ready to install a 240v dedicated supply in my attached garage.

    Thanks! Andrew C.

  28. Good Grief, hire a professional for your videos. You NEED neutral density filters on your camera to see working welds in action. Everyone thinks they're a pro videographer. LOL.

  29. vertical down is asthetics only..penetrations just not there.and if you work on your style you will lay a beautiful weld no need for vert down

  30. Those are some sweet welds. I always seem to have a hard time following the gap/joint to be welded. My welds meander around. Maybe my shade is set too high? I'm paranoid about messing up my eyesight.

  31. pretty sure i've heard quite a lot, NOT to push your puddle with Flux wire. Would not welding straight up be pushing..?..?

  32. The Lincoln video on nr232/233 is much better than this one…you guys (in the comments section) should check that one out. ……no offense.

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