I built some earth anchors recently out of some 3/16" and 5/16" c channel. I don't have any photos of the prepared edges but I ground them off to give me a deeper root. I was running my Miller 180 on max for most of the time and all welds were made with.035 flux.Because I needed a flat back I didn't weld the back sides and just left them as flat as I could get them lying on the ground. I cooked the inside though! Good penetration throughout. It was a good learning experience trying to weld the irregular shape of the channel.And here is one installed.Thoughts and critiques welcome. I know the welds show a lot of spatter and I didn't bother cleaning them up with anything other than a wire brush and chipping hammer to remove the slag.