Welding Tips and Tricks

I need to do bodywork on my truck which type welder Works best for fender work

MIG. 0.024 wire, 75/25 gas. TONS of small spot tacks. Skip around to avoid warping the panel from the heat, use some chill bars whenever possible, and be PATIENT. Let the metal cool and avoid trying to run long welds.

Honestly, the one you feel most comfortable using. But there are a LOT of qualifiers to that statement for many late model vehicles. For some late model vehicles, the manufacturers may suggest some very esoteric welding techniques like MIG brazing with silicon bronze wire. On the 2015 and newer Ford trucks with aluminum bodies you need to use an aluminum capable process such as TIG or pulse mig (most body shops are using pulsed MIG). GM doesn't recommend the use of heat or straightening on any of their high strength steel body panels and recommends replacement only. Some of the steel alloys between mild steel and "ultra high strength" steel can be welded, but MIG with ER70 S-6 or low alloy wires is recommended. https://www.repairerdrivennews.com/2018 ... -on-i-car/

The issue with the low alloy steels and ultra high strength steels will be cracking and or annealing the metal and losing some of the stiffness required as manufacturers have moved to thinner and thinner steels to reduce weight in vehicles. How old is your truck?