How do you weld a seam that is almost invisible on your body panel? Take some time to make your replacement patch a perfect fit. Ideally, there should only be a 1/32″ (or less) gap between the patch and the body panel. Place the welding tip wire through the gap and tack-weld the patch in place (put a couple of small spots of weld here and there). This holds the patch in the correct position. Next, begin welding a small portion at a time (1/2″ to 1″ usually works the best). Be careful not to weld too much at once, as this would warp the body panel.
Once the welding is complete, carefully grind the welds flush with the existing body panel. Further welding may be required to fill the areas that were missed. Wire feed welding is a good weld for beginners to try. Try practicing on a piece of scrap body panel before attempting to weld your body panel.
Tip: when purchasing a wire feed welder, make sure it’s a name brand and purchase the welder set-up that uses the argon gas rather than flux core wire. Gas aided welding is much smoother and user-friendly. It’s a little more costly, but well worth the investment.