Thank you, Jody.   Just watched it.   I must admit I’d forgotten about that video, and I was even there in the live call.    I reckon it was about a year ago.   I even asked about the pulse frequency, thinking it was under the operator’s direct control.   (The answer suggested pulse frequency is indirectly affected via the trim setting.)  It was really good to watch it again.    And it’s left me wondering if pulsed MIG might one day render short-circuit MIG, with its potential for cold-lap welds, obsolete.     It seems the development of pulsed MIG is definitely something to watch out for in the future.   Thanks again.   I do hope we can see more of it in future in WelderSkills.

Jody,

Could we possibly have a webcast (or 2) on pulsed MIG? I’m hearing more and more about it (from you and the other instructors). It’s been around for a long time but perhaps not very long in terms of equipment at an accessible price. I’m getting the feeling it is going to become more and more popular and will be increasingly used where other forms of MIG/MAG are now used, but I may well be wrong. So what is it, where is it going, what are its limitations, how do parameters and techniques make it different from other forms of MIG. And what are the things to watch out for?

Many thanks

Really great bit of experimentation, JD.    I love it when the received wisdom, passed down for decades, gets challenged and when we find things aren’t as the textbooks kept telling us!     If you get the opportunity (and inclination), it’d be interesting to see what happens with the same setup but ~20%-25% less gas flow, and then a clear cup but at the same gas flow as you previously used.

Excellent. Great commentary explaining what and why. I would have asked how you made your choice of filler wire, but you explained all that perfectly. And a great reminder that we’re still dealing with potentially lethal voltages. You could easily have edited that out, but we would have missed a valuable reminder had you done so.

Thanks, Brad. Excellent video.

Wow! That is excellent. I love it when one of the instructors does back-to-basics research like this. The thing is, because of the instructor’s experience we can rule out any variables such as poor technique, in general anyway. Now, it strikes me that the difference between flush and 1/32” isn’t much at all, although the puddle is probably much easier to see at 1/32”. So the first thought I had is: it must be more difficult to see the arc and the puddle when flush than at 1/32”. So is it a real effect, or, with practice, would you produce just as good a weld when flush?

So, assuming you used a ceramic cup, would you get a better result with a clear cup?

Next thought, with the diameter at the tip of the cup being slightly constricted (I’m presuming), the gas speeds up a lot right at the end of the cup, which is where the tip is when it’s flush, and then slows down after it’s exited. Whereas, at 1/32”, the tungsten tip is in the slowed-down gas region. So could it be a gas flow effect; you could test that theory by, say, reducing the argon flow rate on the flush setup by, let’s say, 25%, and see if that improves things.

Sam, other than using pulsed mig to minimise distortion, did you take any other steps to avoid distortion, such as backstepping, welding in a sequence that, for example, mimics the torqueing down of a cylinder head, and letting it cool for a few minutes between beads?

Sam, are you discovering parts of your truck full of kit that you never knew you had? If Aladdin were alive today, he wouldn’t have a cave full of treasure: he’d have your truck.

You have such a wide range of skills that I’d describe you as “an engineer’s engineer”.

I subscribe to ScannerDanner’s premium content, and he, too, loves, and makes constant use of, his power probe.

Good to see that you use Fluke kit; I’d never seen a detachable meter readout unit before; what a clever and useful idea.

Still waiting to see your first-aid kit 😉

Martin

I love all this testing, rather than theorising, Jody. I’m so glad you raised this topic, because when I’ve seen the puddle holding backing at the tip of the puddle, I’ve always thought it can’t be really punching deep into the root. On the other hand, when I’ve seen the front of the puddle flowing ahead and deep into the root, seemingly being pulled forwards by capillary forces, I’ve thought that is the optimal case. But your cut and etch proves beyond a doubt you’re getting perfect penetration even when it doesn’t look like it. And the toe of your puddle certainly looks nice and fluid. As you said, increasing the current runs the risks of nipping the corner or casing undercut. It’s really good watching this as an observer and under high magnification, and it beats all the theorising in the world.

Thanks, Jody.

It was indeed another excellent podcast; they’re always worth setting the alarm clock and waking up for so I can listen live.

Thanks again, Jody and Sam for making it so interesting and entertaining.

Martin

See you there, Jody & Sam.