Bumping this thread, as I have the same question. Just bought a 1973 Hobie 16. It needs quite a bit of TLC, and will likely be my summer project.
As others on this thread have mentioned, one of it's problems is that the multitude of black anodized parts are all scratched. Everything is structurally sound, I just want to make it look as nice as possible. I'll only be lake sailing, so salt corrosion should not be a problem. I've googled this multiple times, and have found the following advice:
The best way to make the black parts look nice is by using Penetrol. Despite the fact that this is designed as an additive for alkyd based paints, I tried it on some of my metal and it makes the black anodized parts nice and shiny. Seems to work well, but (of course) does nothing for the silver scratches. For those, I've found the following suggestions (and would love input into which (of any) are worthwhile:
1. Live with them as is. It's like grey hair, best to just leave it alone.
2. Use Aluminum Black:
Seems to be marketed to gunsmiths. Several posters suggest using it, but no one talks about whether it works well or not.
3. Use Black Nail Polish
4. Use Black epoxy
5. Use black paint
I am open to any and all suggestions. If you've tried something and it's worked, or not, I'd love to know. I realize that nothing will be as good as the original anodized surface, I'm just looking for the next best option. Re-anodizing anything is not really in my budget.
Thanks in advance!