G'day all, I decided to tackle a job I'd been putting off. The hood was really quite nasty with pitting evident. A 4 day soak in seasoned (Thanks @MYN) vinegar and a buff & polish has produced reasonable results. I think anytime you start a project and you can see a difference for the better at the end of the project, you've had a win. The hood actually looks worse in the photo than real life. I think the black spots is polish that has gone into tiny, rather than microscopic, craters as caused by pitting. I might drop the hood back into vinegar for another 4 days and see if that reduces the pitting.
It's amazing the results you can achieve with a few simple household products... and a lot of hard work!
The trouble is once chrome has pitted the rust just keeps coming back. You will be chasing your tale with this every few months. Certainly a visual difference for now. I can remember most towns and cities having a 're-chroming' works, some back street lock-up with lots of dip tanks, electrodes and chemicals. I'm sure that it is not environmentally acceptable now but boy were they handy for motorcycle front forks, mud guards and hub caps ..
As Henry said they are alumimium. Here 1949 AGM 3025 you can see what they should look like as they sit on Neils lamp.
That's excellent results, Matty. Aluminium doesn't rust in the way steel does. Once the thin oxide film forms, its already quite resistant to normal atmospheric oxidation. The oxide film is quite tough, I'd say. That's provided you don't get caustics and strong acids splattered over it.
@MYN I knew what I was up against because of previous experience in fettling Wizard Light Co aluminium hollow wire lamps. After the last hollow wire lamp I did for @Pchamp I thought the next time I tackle badly corroded aluminium I would soak it in vinegar then use 400 then 1000 grit wet 'n dry sandpaper. Of course, I forgot the sand paper step this time around. I think I might give the 1000 grit a try on this hood then re-polish it.
