Don, The 90 degree bends have a slight radius and when they are butted up next to each other it leaves enough of a gap to skip weld on the seem on top and still be able to keep it flush on the window, and the bottom seem will also be skip welded though I have to do it without drooling the weld down the sides. I don’t know about polishing it, but plans are for it have a clear or black anodize. Tony