exnailpounder wrote:...you need some chill blocks to draw the heat out of the SS.
Also, welding outside corners splits you gas and draws in air so set up some type of dam along your weld line to trap argon. This should all help you with your color.
^^^ This is really good advice. Because what you are welding is so thin, you're putting too much heat into it and drawing contamination in from the backside. Your travel speed looks really slow too. Once SS gets hot, don't d!ckbeat, move. If the fit is decent, small filler wire is all you need. I'd even recommend 0.045 wire for these corners. Stuffing the backside with tinfoil will help trap the Argon and prevent "sugaring".
As soon as you stop welding, scrub the bead with a clean, stainless steel brush. It will polish up your weld very nicely, even if its grey. But pick up your speed would be my strongest advice. I made some SS brackets yesterday in fact from 1/8" and used my Fupa 12 cup, outside corners. First I've used it, and was very pleased with the outcome. Don't know whether it was the "key" but it didn't hurt.