aluminium corrosion

Replace it or patch it, Once its gone its gone,

Brush it down with a wire brush to get rid of all the powder. You might want to dig it out of holes with a screwdriver or similar. The treat with etch primer, maybe two or more coats. Follow with ordinary primer and top coat. You won't see it so the colour doesn't matter; use up all those old aerosols from cars long gone! It won't look pretty but in my experience it will stop further corrosion.

It might also be worth painting the inside of the cappings so as to minimise the chances of metal to metal contact, which is where the corrosion occurs.

Gordon

sounds good. thank you. Richard

If you have a sand blaster - that works very well to get back to bare metal.

I have found that Bondaprimer works very well on bare 'aluminium'.