You might be able to. You might give that a try first, but I wouldn't spend a whole lot of time on it. Pretty easy to cut a chunk out for access and then weld it back in, and a lot less trying on the patience than trying to sneak a nut back there and hold it in place while you weld it. I know how that would go if I tried to do it, so, I'd just cut an access window and fix it when I was done.
Did you do any gusseting or seam welding on that K before you had it painted?
