The photo shows you the most red you ever want to see at one time. Think of it as building up the area with a series of tack welds. Never run a complete bead. If you are welding for more than about one second at a time, you are taking too long, so you might want to practice on some scrap to get your settings right before you attempt this for real. Your goal is the minimum heat that still yields good penetration. Wire in the 0.023-inch range works well.