If a welder is certified to use the Mig Pulse process would this certification also cover the use of Mig short arc or is Mig short arc a completely different certification?
Welder Qualification WPQR is dependent upon essential variables of the weld procedure WPS.
Essential variables are code dependent ie AWS, ASME, DIN etc. Codes require separate procedure WPS and welder qualification WPQR when welding variables deviate outside of the limits of qualified ranges in the codes (You have to requalify your welder and your procedure in accordance with the respective code).
Easier said than done (Takes a bit of time and money)
The most common problem with PulseGMAW is lack of fusion in the pulsed portion of the Volt/Amp cycle. Typically PGMAW is used to lower overall Heat Inputs or to help poor welders make better looking welds (Typically in Aluminum).