MIG welding uphill requires a little bit more work than when welding on a flat, horizontal surface. Weld in an upside down “V” pattern in order to trace the leading edge of the puddle and limit the metal’s convexity. If that isn’t your style, just use any technique that will help keep the arc on the leading edge of the puddle and allows you to control convexity. For more suggestions when MIG welding uphill, click here:: MIG Welding Uphill Lap Joints