Uphill MIG Welding Settings Plus a 2F Horizontal Outside Corner Joint

Uphill MIG welding refers to the welding position where the weld joint is positioned at a vertical and upward angle relative to the welding direction.

In contrast, flat position refers to when the weld joint is horizontal or parallel to the ground. The welding settings for uphill are usually lower than for flat or horizontal position.

Voltage and Amperage: Uphill welding generally requires lower voltage and wire speed settings compared to flat position welding. This is because uphill welding involves gravity and requires a bit less heat input to get adequate penetration and fusion in the joint. The lower voltage and wire speed settings help to avoid excessive convexity in the bead due to gravity pulling down on the molten puddle.

Downhill Mig is much quicker and easier but once you get to around 3/16" thick, downhill short arc mig welding just doesn't penetrate  enough.

It is slower and more difficult to get a good looking weld going uphill with short circuit mig welding....but its the way to go on 1/4" and thicker for anything important.

1. Travel Speed: In uphill welding, the travel speed tends to be a bit slower compared to flat position welding. Slower travel speed allows for better control over the weld puddle and helps ensure good penetration provided a technique is used that plays the arc to the leading edge of the weld puddle.  
2. Gun Angle: The angle at which the welding gun or torch is held can also vary between uphill and flat position welding. In uphill welding, the gun angle can be dead nuts 90 degrees or slightly leaned back a bit.  
3. Shielding Gas Flow: The flow rate of the shielding gas can also differ between uphill and flat position welding. Uphill welding often requires a slightly higher shielding gas flow rate to provide adequate protection to the molten weld puddle. nozzle diameter also determines the gas flow rate needed.
4. Stickout:  with short circuit mig welding, a short stickout helps a lot with vertical uphill welding.  some nozzle tip combinations have the contact tip recessed way back in the tip resulting in a long stickout. I sometimes trim the nozzle if I cant get the right nozzle tip combo. I really like the contact tip to be flush with the nozzle for short circuit mig and I find it really helps.