Voltage Vs wire feed speed.

[Mick B]

I'm afraid I cannot understand electricity, mainly because you can't actually see it working like when you pull the back off a watch or look inside a gearbox.
So my question this time is............................
I take it that the voltage selector dial on my mig welder kind of adjusts the physical size of the weld and the wire feed speed (or amperage) adjusts the penetration. I realise that both controls need to be adjusted to work together. Maybe I'm completely wrong ?

Mick.

 

[dan.taylor.1]

They both affect the weld in a few ways, voltage helps to wet the toes of the weld im, you'll find if is too low the edges aren't melted in to the material being welded. Also wrong voltage can cause excessive spatter. The wire feed speed does change the current but so does upping the voltage to an extent. Basically play about with it till yoi get a good weld, dont fall into the habbit of weaving, I did and its taken me 3 years to kick it, I can now lay weld on my stuff im happy to say I did! A good tip is to record the settings with material details too so you can go back to them rather than guessing!

 

[pedrobedro]

The Miller site explains it in an easy to understand way, have a read. Wire thickness and arc length also affect your weld.

 

[Richard.]

The arc length will always remain the same on mig as it's a semi auto process but the stick out length will effect your current and then effect penetration. Voltage effects the width of the arc and on certain machines can be turned up high enough to get into spray transfer. Amps (arc current) is generally adjusted on the wire feed rate and this effects the depth of penetration. You need to get them singing in harmony for results but this generalisation will help with trouble shooting. Eg if you find yourself burning through a lot knock the wire speed down a touch but then you might find this starts to encourage a bit of undercut at the edges where fill isn't sufficient so travel speed or voltage may need to drop a fraction also. It's a "getting a feel for it thing"

 

[Mick B]

Thanks Richard, so I think I'm on the right track. Whatever I'm doing must be OK because I sometimes cut a practice section off and try to bust it in the vice and have a look at the penetration as best I can without doing all that polishing and etching stuff.