Hello
I am curious if anyone has polished a raw KH frame to a mirror finish like KH cranks?
If this can be done is their any product/process that can then be used to coat the frame and protect it a bit like paint but obviously clear and that would enhance the aluminium look.
Thanks
Felix
Since they are made of aluminium, it’s probably doable. You might have to remove the coat of blue if it was added by anodization (instead of paint).
Then it’s a matter of elbow grease and sand paper, all the way to 2000 superfine, then finish with aluminium wax. You’ll probably have to wax it every week so that it stays shiny, or varnish it.
make sure you use a clear coat that fits the application, most clear coats for wood (urethanes) will yellow quickly when in the sun.
So why do the cranks need no wax or clearcoat? I thought they’re also just polished aluminium. Or do they have a coating?
My guess is that they are polished, and then anodized. If there was no treatment they would oxidize pretty quickly and lose the beautiful mirror shine.
When I needed to clean some scrapes off of the clear coat on some carbon fiber brake levers I used Minwax Helmsman spar varnish (polyurethane) because it is designed for outdoor use, and not to yellow.
You can get an automotive clear coat for aluminum wheels that’s supposed to be pretty durable. It’s a two-part catalyzed in the same spray can – you punch a button in the bottom to combine the parts, then it’s a one-time use. I’ve never used it, but it sounds pretty good. Look on Eastwood (or similar).
I think some powder coaters have a clear coat also.
Anodizing would give it kind of a silvery look. I’ve never seen a mirror finish anodize.
Polished aluminum is anodized all of the time on bike parts. I know what you mean about the silver look, but I also know that Dura Ace derailleurs are anodized, and have a mirror finish.
EDIT: Apparently part of the anodizing process for coloring parts is etching to open “pores” in the aluminum that allow the dye in. When parts are available as colored or silver anodized they still etch whether or not they dye it, so it looks silver instead of polished. The anodizing itself can be done whether it is etched or not.
This guy polished his KH 36er. It looked very nice when he got it all put together. I don’t know if he put on a clear finish to protect it. That was year ago. Maybe you could ask him for a recent picture to see how well the shiny finish aged.
Thanks for that info, jtrops!