Diagnosis for a weld issue ;)

[Davek0974]

Looking for education

If I said my vertical-down fillet welds were much better than say a horizontal fillet what might be my issue?

The vertical-down has a nice concave finish and the horizontal has a pronounced ridge along the bead.

What might be the go-to thing to look at???


Thanks

 

[Troy]

V down has gravity helping
If you have a the correct power for the weld you want to achieve try increaseing your travel speed or drop the wire feed rate a small amount and try again , pictures would help

 

[Davek0974]

V down has gravity helping
If you have a the correct power for the weld you want to achieve try increaseing your travel speed or drop the wire feed rate a small amount and try again , pictures would help

Here we go, picked a pair with the most pronounced difference...

 

[davidjohnperry]

Turn the volts up

 

[Davek0974]

Is this flat position horizontal or over head ??? Turn the volts up or as above

Would be flat position horizontal

 

[Munkul]

Concave in MIG welding is baaaad

 

[Davek0974]

Took the Esab Rebel out of sMig (first time) and set a few variations, seems to land on 19v and 6m/min, this is 0.8mm wire and 3mm sheet.
Horizontal - flat base/vertical upstand...


Down...


Up...


From just reviewing welding tips & trick video, it seems vertical down is shunned most times due to lack of penetration, also too much bead is generally bad.

I think these tests show a little improvement??

 

[Davek0974]

Concave in MIG welding is baaaad

Flat is good or slight bead yes?
I usually seem to get a very high bead.

 

[TechnicAl]

From a Welding Engineer point of view the convex is preferable over the concave....stronger joint

 

[Davek0974]

Do those last pictures look reasonable?

 

[Munkul]

Looks good to me 6m/min on 0.8 is quite low on amps unless you're going uphill, though. I'd want to go up to 7.5-8m/min and travel faster for 3mm plate.

I said concave = bad because in general, you only get that effect with either low amps and lots of manipulation, or welding vertical down.

I'd never MIG anything vertical down that I had to rely on. Read this:

http://www.weldingtipsandtricks.com/mig-welding-techniques.html

 

[Davek0974]

Looks good to me 6m/min on 0.8 is quite low on amps unless you're going uphill, though. I'd want to go up to 7.5-8m/min and travel faster for 3mm plate.

I said concave = bad because in general, you only get that effect with either low amps and lots of manipulation, or welding vertical down.

Here we go - 19v 7.5m/min 110A any better?

 

[Munkul]

Yes, looking good. You could increase travel speed a little to stop it looking so peaky. Or manipulate the torch a bit - I like the little "e" shape for short-circuit MIG, personally.

Problem with MIG welding is that it's really easy to make it look fine - all your welds look fine, by the way - but not necessarily fused into the base metal properly or not. I'd say 110 amps was ok, but still a bit cold.

https://www.millerwelds.com/resources/weld-setting-calculators/mig-solid-core-welding-calculator

The wire speeds and amps for these thicknesses from the Miller calc are pretty spot on