Hi there

Is the transition to spray transfer at a lower current with a smaller
1.0mm diameter (39thou) wire than with 1.2mm (47thou) wire?

With Ar-15%CO2 I reckon it's
1.2mm dia -> 240A
1.0mm dia -> 220A

What do you reckon?

Reason for asking is, at lower thicknesses, that might be enough
difference to enable spray transfer to be retained, not some other
mode.
It seemed to make a useful difference for some box sections, for
example.

I've never thought about it until recently because quite a lot of
air-cooled torches can take 240A spray with 1.2mm dia wire, but
overheat and ****-out with 1.0mm dia wire.
Which can be understood
1/1.2 of contacting electricity pick up surface
1.2^2/1 = 1.44/1 wire feed speed increase

So in general you'd want 1.2mm dia wire when "spraying".

But with a water-cooled torch (gun) on an industrial machine - the
torch can take spray with 1.0mm dia wire, and obtaining spray at a
lower Amps might make that crucial difference enabling clean, smooth,
efficient, fast spray transfer to be used on lower thicknesses.

Your experience says??