120-Volt Mig welder.

[MinnesotaDaveChalmers]

You're very welcome guys - hope the info helps
After a while, a guy tends to make the small adjustments kind of automatically just based on how the puddle and arc are behaving themselves

OK here's how the 3/8 thick test plate (welded with 120v) bent.

I bent only weld#2, the weld discussed earlier. It was very strong, had to reef on that 20T press to bend it to the 90-ish deg as shown.

From what I can see looking at weld #2 it's pretty obvious that:

---> #1 will be weaker
---> #3 will be stronger

But even though weld #2 was not 100%, it would not let trailer parts loose on the highway, it was firkin' strong.

Very nice testing - you can clearly see where the root that wasn't fully fused started splitting apart, but the fused part stayed together. Nicely done

Over time, the cracks that start in the non-fused part tend to "zipper" through the rest.
It generally takes a very long time - but if well hidden tend to let go without warning.
Many of have seen this when we analize a broken item that comes in and the 6" crack is rusted all the way except the last 1" that suddenly broke the rest of the way.

If I had any advise, I'd try making that cover pass in two or three smaller beads - on the screen it looks as if your machine had a hard time carrying a bead that wide. No way to tell from my couch of course - you'd be the only one who could see it as it went in.

Any way you could do a face bend of one of the other welds to see if the cover pass stays together, splits in the middle, or pulls away from the bevel?

 

[Sodo]

After a while, a guy tends to make the small adjustments kind of automatically just based on how the puddle and arc are behaving themselves

Yes Dave I know what you mean. Arc's been behaving as of late, but who's "the puddle"?
:laughing::laughing::laughing:

Over time, the cracks that start in the non-fused part tend to "zipper" through the rest. It generally takes a very long time - but if well hidden tend to let go without warning.

"Tend to (crack)",,,,, ONLY if there is stress or flexure in the weld joint. Steel doesn't tend to grow cracks on its own. And, if this was used in real life the prudent weldOR would bevel and weld it on both sides.

If I had any advise, I'd try making that cover pass in two or three smaller beads - on the screen it looks as if your machine had a hard time carrying a bead that wide. No way to tell from my couch of course - you'd be the only one who could see it as it went in.

Any way you could do a face bend of one of the other welds to see if the cover pass stays together, splits in the middle, or pulls away from the bevel?

Remember it's 120volts welding 3/8" steel, the machine's got to be near a limit of sorts. But I think most people can see that 1/4" steel is well within the capacity (for this type of beveled weld).

If I cut it at weld#2, I could bend the others.

 

[skylarkguy]

But even though weld #2 was not 100%, it would not let trailer parts loose on the highway, it was firkin' strong.

So you are happy with this weld?

 

[Sodo]

So you are happy with this weld?

Actually, yes, it is perfect because upon bending it shows the difference between full penetration and not. It was very strong, almost as strong as virgin flatbar, to bend it took some serious pumping on that 20T press. I think weld #3 might be better.will bend it someday.

 

[skylarkguy]

To me it would demonstrate that it was incomplete weld. While the part that had complete fusion to the root was strong much of the length was not fully welded. Maybe that is good enough.
I was hoping this thread would generate some scientific testing (controlling variables, replication etc). Your sample of 1 tested weld is promising but inconclusive at best.

 

[CNC Dan]

Actually, yes, it is perfect because upon bending it shows the difference between full penetration and not. It was very strong, almost as strong as virgin flatbar, to bend it took some serious pumping on that 20T press. I think weld #3 might be better.will bend it someday.

To help with bending, cut 1" coupons.

 

[Sodo]

To me it would demonstrate that it was incomplete weld. While the part that had complete fusion to the root was strong much of the length was not fully welded. Maybe that is good enough.
I was hoping this thread would generate some scientific testing (controlling variables, replication etc). Your sample of 1 tested weld is promising but inconclusive at best.

Skylark, this weld's entire reason for being on this earth,,,, is for instructional purposes. Weld #2 displays a "fault" that can be discussed, an example that members can see and understand, so it's more than good enough, it's "perfect".

I too was hoping this thread would generate some scientific testing, controlling variables, replication. But who's willing to do that work on a hobby/maintenance forum? Just Shield Arc, and Sodo. Now Just Sodo, who offered up 30 minutes of cutting, welding, and a couple hours of pics, typing & attention.

"Good enough" may be all you get. Unless this forum can attract someone else to step in and help - but they need thick skin.

To help with bending, cut 1" coupons.

Yup Dan, that would have been easier bend but takes more time which I did not have. Who does have the time for free instruction? Lots do, but it really takes more time than you'd think.

So for now it seems to be only me welding and posting pics, but I'm not an instructor, I shouldn't be spending my time like this, and my eqpt is 100+ miles away. I'm appreciating that MinnDave is stepping up though!

 

[Reverser]

Skylark, this weld's entire reason for being on this earth,,,, is for instructional purposes. Weld #2 displays a "fault" that can be discussed, an example that members can see and understand, so it's more than good enough, it's "perfect".

I too was hoping this thread would generate some scientific testing, controlling variables, replication. But who's willing to do that work on a hobby/maintenance forum? Just Shield Arc, and Sodo. Now Just Sodo, who offered up 30 minutes of cutting, welding, and a couple hours of pics, typing & attention.

"Good enough" may be all you get. Unless this forum can attract someone else to step in and help - but they need thick skin.



Yup Dan, that would have been easier bend but takes more time which I did not have. Who does have the time for free instruction? Lots do, but it really takes more time than you'd think.

So for now it seems to be only me welding and posting pics, but I'm not an instructor, I shouldn't be spending my time like this, and my eqpt is 100+ miles away. I'm appreciating that MinnDave is stepping up though!

Thanks for the test, Sodo. Good job! :thumbsup:
It's interesting that part of the root had complete fusion and some wasn't quite completely fused.

That makes me wonder that if fluxcore wire was used, perhaps there would have been complete root fusion throughout, since it is said that fluxcore does penetrate better than solid wire?

 

[CNC Dan]

Yup Dan, that would have been easier bend but takes more time which I did not have. Who does have the time for free instruction? Lots do, but it really takes more time than you'd think.

Isn't that the truth. I have a Lincoln SP125+ with .035 flux core. If i get a chance this weekend I could try welding up a joint. I would have to make a jig to bend it on, but I do have the 20T press.

Can you recomend a type of joint/thickness. Not sure what I have on hand though.

 

[Sodo]

The 'variation' that I intended to test (in welds 1,2,3) is the separation of the 2 plates. Weld#1 was 'together'. Weld #2 was about 1/16 apart, weld #3 about 3/32" apart. Not scientifically controlled or measured, just goin' at it for 3 welds, then pack up and go home. I did not expect it to work out this well, with 1=fail, 2=half fail, 3=success. (assuming 3 = success)

Anyway, welding any steel with a fusion type method you must have a 'puddle' or melt or it's just a blob resting on steel, not fused. In this case the 3/8" thick metal will draw the paltry 120v heat away so you need an 'excuse' to keep the trigger pressed longer.

Separation of the material increases the time that heat is applied to the piece, takes longer to fill the gap, and thus increases the time the trigger is pulled = more heat input. And (I think) MUST be part of your methodology in using a 120v on material thicker than whats printed on the box. Not having any pro or genuinely interested instructors involved makes this kind of a crapshoot but conclusions can be drawn from the test and the pics. And that's about all we have available currently.

I wish MinnDave, Dan, or some new (interested) member had some time to show some of this stuff.