I am getting ready to use a borrowed Hobart Ironman 210 with CO2 shield to weld in a 3x3 inch patch on the thin quarter sheet metal of my '69. I'd appreciate any input on settings -- better to ask advice than to burn holes!

Thanks in advance.

Well, I can say what settings as I have a Miller 130, but I'd suggest getting a scrap piece of metal of the same gauges and practice with it at the angle you'll be welding at.

On my Miller I'd set it at 1 or 2 (1 first) and go for a wire speed of about 15-20, but all I'd be doing is spot welds and skipping about every inch. Let it cool or use a wet rag to help it cool down more quickly (this will help shrink some of the stretch you've caused in the area. Make sure both the front and backside of both pieces of metal are clean and grease free. Try to not overlap the metal, try and make the patch fit inside the hole with an almost interference fit. After putting down your spot welds, hammer and dolly them and the gaps to make sure everything is flush. Take your time and don't rush and when you get done and have sanded it down, you'll likely not know that it was ever patched.
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Larry Hampton
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'63 Fairlane 2-dr post. Race car since at least '67. In the process of turning it into a proto-clone Nostalgia Super Stock car with FE power and three pedals.

Thanks. I definitely was going to stitch weld it, just unsure if the lowest setting would be too cold.

The last sheet metal welding work I did was on a 68 and that was 30 years ago, and I used gas then.

I have a lot of thin metal around to practice with, then will do the floorboard replacement first before the visible quarter patch.

Sounds like a plan.
_________________
Larry Hampton
______________________________________________

'63 Fairlane 2-dr post. Race car since at least '67. In the process of turning it into a proto-clone Nostalgia Super Stock car with FE power and three pedals.