Polished cranks - clearcoat or not?

[smead]

Would like to hear from those who have first hand experience spending all that time polishing cranks to a mirror silver finish. Of course clearcoat would preserve the finish, but am sure it'll get chipped up over time and would require more labor to strip and redo down the road. Am tempted to leave em' raw and just break out the mother's polish every few months. This is the first time I've polished a set of DA 7700 cranks and wow, the finish looks like a silver platter.

[zzy]

leave 'em raw

[one60]

I've posted a Southwest Frameworks bike with mirror polished components here. It didn't require regular polishing to keep it shining. If it gets dull or scratched, the surface can be brought back to a shine with very little effort.

Meguiar's mag polish works good but the Billet polish gives an even brighter finish.

Once you've stripped any anodized coating (Jestco deanodizer works great), getting a mirror polish isn't too difficult. I'd recommend working on a practice piece like an old quill stem to see if you have the patience.


https://forums.thepaceline.net/showthread.php?t=203208&highlight=southwest+frameworks

[54ny77]

Leave raw. Spend 10-15 min with soft cloth and simichrome or similar soft non-abrasive metal polish every so often, depending on how grimy it looks.

Don't clear coat it.

[zmudshark]

I've found that the upkeep to keep polished cranks clean is crazy. Maybe some climates are better than others. I had a polished DA 74xx crankset on a bike at my folks in S. GA. I had to go over it every day or two, tops.

It might be better in AZ, but nothing beats anodizing.

[ultraman6970]

The main reason to avoid clear coat is because the clearcoat has nothing to adhere to once the metal is polished and the clear will start cracking and peeling off the surface.

[bikinchris]

Maybe try a carnuba wax? If that doesn't work, you can always polish it off.

[macaroon]

Get them anodised with a clear finish?

[Veloo]

Anyone know what Campy does? Is that a clear coat on their silver groups or some form of anodizing?

[one60]

The OP wanted a mirror finish. I do not believe the mirror finish will be retained following a clear anodizing. The added cost is another consideration.

Using a clearcoat, just complicates matters. Assuming it would adhere properly to a polished surface, if the clearcoat is scratched it would have to be sanded and buffed to maintain the brilliance just like an uncoated but polished aluminum part.

The well intended suggestions here are attempting to solve a problem that doesn't truly exist. I'd suggest contacting a professional like CycloRetro for insights?
https://www.cycloretro.com/polishing

[zzy]

The well intended suggestions here are attempting to solve a problem that doesn't truly exist.

You realize there are people here, like me, who have done the exact thing OP is talking about? I've polished several sets of 7700 and a 7402 crank. Raw is the way to go, and doesn't even look bad after it oxidizes. And you can absolutely get close to a mirror finish with the right polishing compound and a rotary tool. No sense in complicating a simple job with clear or re annoing it.

[54ny77]

i think you misunderstood what one60 was saying. maybe i'm incorrect, but i read his response as clearcoating is a waste of time, and leaving it polished finished (which in turn requires occasional maintenance) is the way to go.

some fine metal polish, a soft cloth, a cold beer and a lazy afternoon.....it's the price we pay for the SHINE!

heck, i have two sets of hb son polished, non-clear coated rims. they are stunning when cleaned up. but getting them there....it gives me memories of days of yore when rims were all silver and black anodizing wasn't yet a "thing."

on my crank project, i stripped then polished a shimano crank. before polishing the front side, i scuffed up the back and painted it with silvery "aluminum" spray paint (a few coats), then baked it in the oven for awhile. next step was tape off the paint then go to town polishing the front side. i was pleased with the outcome.

every month or so i hit it with some simichrome and all's good.

You realize there are people here, like me, who have done the exact thing OP is talking about? I've polished several sets of 7700 and a 7402 crank. Raw is the way to go, and doesn't even look bad after it oxidizes. And you can absolutely get close to a mirror finish with the right polishing compound and a rotary tool. No sense in complicating a simple job with clear or re annoing it.

[macaroon]

The OP wanted a mirror finish. I do not believe the mirror finish will be retained following a clear anodizing.

What makes you say that?

[54ny77]

because clearcoating always introduces a slight haze. the degree of haze depends on the finish used (brand and product code). you'll never get a mirror-finish clearcoated piece of aluminum. look at car rims as a guide, for example. high end rims that are mirror polished are not clear coated, and for a reason.

i've spoken with several automotive painters about clearcoating polished bike parts and they all said the same thing. they can get it coated, sure, but it'll never look like a mirror. finding a very good automotive painter who is interested in the job will itself be a challenge--you gotta find one where, typically, the painter is a bike geek and digs the idea of the job itself.

if you must have it clearcoated, just keep in mind there are tradeoffs. personally, the benefit (which is only that of no maintenance other than cleaning) doesn't outweigh the offset of mirror finish.

What makes you say that?

[one60]

apologies if my comments were misunderstood. As 54ny77 and others have suggested, the most effective way to retain a mirrored finish on aluminum is to leave it uncoated and polish it when needed.

[smead]

Mirror finish (close to chrome) is the goal, and I appreciate the responses, and yes leaving raw is what I will do. 90% of the work to polish these out to that mirror finish is getting the original clearcoat layer off. That is the hard part. Once polished and ridden, I'm sure it will dull, but a quick repolish will bring it right back without a lot of effort like the first time.

FWIW, my method was to wet sand starting with 220, then 400, then 600 with alum polish mixed in. Then the last go was alum polish on a clean rag. Came out beautiful, and will look so nice on the Merckx with chrome stays/fork.