I have some polished aluminium Surly Rabbit hole rims and an old school set of cranks that I’d prefer matt black . I could powder coat but the rims are built up and I’d rather not dismantle if I can get a reasonable result otherwise . On researching the options I came across “gun black” for aluminium . It is often used for gun restoration and seems to give a nice finish with little expense. Has anyone used this product or similar ? Here’s a link to an article where he demonstrates the product on a piece of bare aluminium .
Any feedback appreciated . Thanks
https://www.firearmstalk.com/threads/restoring-the-black-finish-on-aluminum-w-pics.105655/

Not personally but This Old Tony did a video on it last week.

mrpete222 on you tube has also done a few videos on it (often mentioned by this old tony too).

I have used it, it’s not up to much to be honest. I think rims would look scruffy very quickly as it’s not very durable, nothing like anodised. if you can get it to apply consistently over a large area you’ll be lucky.

Masking and painting would probably be better but still a bit poor.

Strip or take the bearings out of the hubs and cerakote.

For most questions like this my first stop is always YouTube these days. There’s always a million different ‘how to’ videos demonstrating the exact thing you’re wondering about.

Touch-up, yes. Whole parts I’d not be so sure about.

I’ve used it for brass mostly, I didn’t get great results on aluminium but to be fair that could be down to prep which is more important with alu than brass I think. I’ve got brass parts that are just gorgeous and they also wore in beautifully and ended up with polished highlights and a whole steam age feel going on, but teh alu was always a bit blotchy/inconsistent and then just wore in ugly ways, it pretty much looked like i’d coloured it in with a pen.

For uneyeletted rims, it’s not impossible to paint the rims on a built wheel. I wouldn’t personally, it swaps one sort of faff for another but it’s doable.