I've kerbed my R/O/S alloy a tiny bit and now the surface of the area around the damage is bubbling up. Its about a 2 inch oval area and seems to be spreading in a veiny pattern.

Is there any method of fixing this such as alloy refurb, or is it fatal? Why do alloys do this anyway, I didn't think they were supposed to rust.

Harrumph!

Alloys can rust/oxidize....if you curb your alloys eventually you'll get bubbling and a white residue forming...this is alloy oxidization...if it were for steel you'll get the brown colour i.e rust.

Refurb is the best way of solving IMHO.