I currently work as a trainee AME and want to eventually start specialising in sheet metal / composite repairs as I've heard the money is really good for these specialist skills. I've bought myself a pneumatic rivet gun to start practicing some basics and have an array of sets for the rivet sizes and types.
My question to any aircraft structural engineers / experienced sheet metal workers in this forum is how to stop getting the smiley faces on the solid universal rivet head? I'm putting enough pressure on the gun to stop it bouncing and the bucking bar is setting a good rivet tail but on some of my rivets I have this smile crease / dent at the bottom of the rivet head. Does this mean the gun isn't in line enough with the rivet? I'm always trying my best to keep the gun 90 degrees to the sheet metal. Or am I doing something else wrong? I've been told I'm using the correct set and air pressures so I'm sure it's my technique letting me down on some of these rivets. Although less mistakes are happening when I get someone to hold the bucking bar so I can use two hands I still have the same smiley face problem on some. Any tips and tricks would be much appreciated.