Welding Tips and Tricks

Hi I’m having some issues with spray transfer practicing for my welding certification in New Zealand. I’m welding a 1G test plate which is 12mm steel with 0.9mm wire. I’m doing the first pass in short circuit then the following 3 passes in spray transfer with no issues. I flip the plate over and grind back to sound metal ( not sure if this is how it’s done in USA but it’s NZ standard) and this is where I have the problem - I stay in spray transfer with my same volts and amps but the arc length changes all the time and big molten balls of wire drop off, not a nice constant spray and the wire burns back. What will cause this when it was working fine on the other side of the plate? Any advice would be great!

Are you grinding out a grove, or just grinding it flat?

Kiwiwelder1 wrote: I stay in spray transfer with my same volts and amps but the arc length changes all the time and big molten balls of wire drop off, not a nice constant spray and the wire burns back.

hi
im not much of a mig welder but that sounds like wire feed speed dropping. ie slipping drive rollers, dirty tip, over heated tip. poor mig lead, worn liner tec. or poor ground after swapping over plate.

are you allowing the weldment to properly cool before welding the other side?