stick welding machines - possible same Amps but different weld performance?

Hi everyone

Is it possible for two welding machine to be set to give the same amps with the same consumables on the same claimed polarity and yet get different welding outcomes - one "a good welder" happily fusing into the joint and the other "giving poor welding performance" with mean and unwilling fusion?

Reason for asking is, sure I much prefer using my Miller compared to the college's Murex (a UK brand) machines.

2.5dia rod 6013 (yeah, "why do you have this fixation with 6013's over there?" - but that's the way it is) 75A DCEP

vert-up T-fillet on 6mm plate (2 reasons - (1) machine I have to use tomorrow can't manage bigger rods running from the generator (2) the college specifies 2.5dia

6013's on 6mm plate for test spec.))

Am I imagining it that the rod is become hotter and the amount of fusion is less with the college Murex machines? On my Miller at home,

75A seems to give plenty of melt-pool fluidity and the stubs do no get that hot.

BTW - that 75A - both welding machines claim it on the current reading dials - but more believably, this is the point for self-peeling slag on a flat position bead-on-plate weld deposits with both machines.

Rich Smith

Arc welding machines vary dramatically from one brand to the next or even one machine to it's brother. Stick welders can have any of the following different from one machine to the next:

-the amperage scale doesn't reflect the real amperage.

-open circuit voltage is different (higher voltage gives easier starts)

-arc voltage is different (higher voltage gives more 'dig')

-wave shape can be different (square wave give more 'dig')

-voltage droop curve is different (affects how the rod feels when closer or farther away from the work)

If there is a high/lo or A/B setting for amperages, the high is usually a slightly higher voltage even if it is listed as the same amperage. Gives better penetration, takes on rust and crud better but the weld bead is not as pretty (or 'self peel' as nicely)

A classic test for a new hire weldor is too screw up the settings on the machine, see how long it takes for the guy to get it right and do good work.

Richard Smith wrote:

that's the way it is)