I have welded up a couple of seat boxes, and now intend to paint them with a
two-pack polyurethane. However I have a couple of questions that need
answering first.



Is polyester filler the correct filler to use on aluminium, if so can the
filler be used directly on the aluminium or should the surface be etched
primed after sanding.



All help on this topic greatly appreciated.

Max.