'70's Campagnolo rims - what color code silver?

Is there a color code for the silver on '70's Campagnolo rims?

My Bora has a need for the powder coating to be refreshed this winter.

Thank you,
- Art

 

If you want to refurb your coating, think of doing it with an adequate process.
These rims are in magnesium and it is necessary to use a chromation process on the surface of magnesium before any coating, be it paint or powder, in order that the coating remains adhesive and protective.
Otherwise you risk having bubbles underneath in a not so distant future, and possible flaking and cracks propagation in the metal.
Unfortunately, only a few shops do the correct treatment for magnesium as it it is very toxic.
That was already discussed in a couple of threads here

 

Powder Coating and magnesium do not go well together. Getting the powder coat off the wheel after the magnesium has corroded under the powder coat ( and it will) is a horrible job. If it is magnesium, just use paint and be prepared for the results to not be a "forever" job.

 

A little help.
https://stevekouracos.com/restoration/tips-and-tricks/aluminum-magnesium-wheel-restoration/

 

The question remains whether anyone knows a color code for the proper silver. I'll surf over to Ivan's website.

Thank you for your other concerns. It comes up every time. Proper preparation, application and curing of powdercoating on magnesium is something my shop has performed reliably and successfully for me and others for many years. I will trust them.
Cheers,
- Art

 

Hello Art...

This is what I have for the Khamsin wheel paint, which may be applicable to the Bora as well:

Sikkens Autocryl
# CF 9070 Gris Metalic

I think I posted this once on the Khamsin thread...

Mike

 

Thank you Mike,
I'm quite sure the Khamsin and Bora would share the same color, so that will do for my purposes.
Best wishes for the Holidays,
- Art

 

On my Bora my spare went bad early on. The wheel & tire place I used in SF back then did all the exotics. The owner had a M1 and a Boxer. They told to throw it away because it had a porosity flaw. This was 1988. I still have that rim somewhere and never delved into figuring it out. I couldn't see anything but it did slow leak. There are products for dealing with porosity in magnesium alloys now. The Bora's wheels appear to me to be of a much higher quality that the ones on my Espada. Gawd what a nightmare Miura style rims can be. That link from above alludes to the issues some of these campys can have. My Espada's were original and had Bondo in many places under that paint. Those castings while beautiful are of a low quality when it comes to cosmetics. That link is what I did after talking to a couple of expert Miura restorers.

I'd be curious to see what a Bora wheel looks like under that paint so please Art ... show us your wheels naked if possible!

There are fillers that survive powder coating just fine. They aren't as easy to use as Bondo though. I have some on a set of intake manifolds I had powder coating silver so that they stay clean.

 

Thanks Bob, I'll have a discussion with the shop about whether powdercoating has qualities that are better or worse than just plain painting. My expectation is that, in either case, the prep is the key to success when dealing with anything made of Magnesium.

Today, I have a further question - What is the SURFACE finish like on y'all's Bora rims? Can any of you share close-up pics like mine below?

I'm attaching a photo of my current state of failure - looks like worms have gotten under the coating. The thing is, I have grown rather fond of the granular "sand cast" appearance, and would think that can't be replicated once I send them to be refinished. If anything there may be significant pitting from any corrosion taking space under that bubbled coating. I guess I just want to prepare myself for these rims coming back to me with a new unfamiliar surface finish, much smoother than I'm used to.

Thanks,
- Art

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Art, those exhibit some serious signs of corrosion under the paint. Mine which are still original show none of that. Have your rims been refinished before ? If you're going the single stage enamel route you can fill with a bondo like product called Icing and/or plenty of primer which can be sanded smooth. Best talk to your powder coat shop about how they do it. Stock, the Bora's wheels while not perfect castings are really smooth. The early ones have polished lips. Not sure about a 75?

 

I agree with Bob, something is happening under that paint and hopefully it is mainly superficial. Here are some photos of my wheels which I do not believe have ever been restored.

Ivan


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Art,
We already had a discussion on the issue of refurbishing mag wheels early this year:
https://www.ferrarichat.com/forum/threads/the-bora.333525/page-35#post-145789994
The current condition of your wheels looks terrible to me, certainly a bad preparation before coating.
You should really ensure that a proper preparation with the dichromate treatment is carefully performed before final coating that should best be painting and not powder coating.
Wish you good success

 

Thank you all, I'm sorry my choice of wording wasn't clear:

Yes, my Bora rims have been powder coated before and the powder coating is obviously failing and yes the failure of the coating is due to corrosion underneath, and yes, that comes from poor prep when that powder coating was applied back in the 90's. I've somehow grown fond of the aggressively granular appearance. I don't think it can be replicated.

Thanks for sharing what yours look like in original form; the casting is smooth, but not perfect. Mine don't have polished lips.

I'll drop by the shop today and share what they say. f I recall my discussion with them about my last set of rims, powdercoating is best done on a perfectly cleaned "metal-only" surface. They won't guarantee the outcome if the rims need bondo, skimming, or fillers. On that set of rims, we agreed they would not perform any cosmetic filling. Their powdercoating was successful, but of course some pitting telescopes through.

I may need to return to enamel paint finish.
Thank you, ,
- Art

 

Art, I'm pretty sure you can do the conversion coating treatment and then powder coat but that won't remedy any thing that requires filling.
I haven't done the Bora's wheels as mine still look like Ivan's. But wow those Espada wheels did have bondo on them and they were original. I even had one original tire on the spare!

Even so Miura/Espada wheels are meant to be a bit rough. The reproductions in aluminum are not though. Gary Bobileff actually buys those and bangs them up, then paints them to make them seem more authentic.

Good luck.

 

Thanks, the rims are at the powdercoater's for refinishing. They inspected the existing finish and vouched it is NOT a powdercoat. So it was some sort of paint finish that failed. Who knows if it was original even. The metal surface underneath the areas we sampled didn't look bad at all. We selected a new powdercoat finish as close as we could match to the Sikkens CF 9070 from a fan deck. IF the powdercoat comes out acceptably, I'll share pics of the result. If not, I'll discuss with another shop to have them stripped and restored to a paint finish.
Cheers,
- Art

 

Art,
Notwithstanding filling issues, it's not clear to me whether your powdercoater will perform a chromate conversion on the "metal-only" before "finishing".
If not, and considering the current poor condition of your rims, I'm afraid that you may encounter flaking/bubbling issues again in a not so distant future.
Mag wheels are a special beast...

 

This shop has successfully powdercoated Campagnolo mag rims for me before. They take it down to bare metal and start from there. We sampled an area to check for the magnesium's surface condition. Based on their observation, they felt they would have success. I didn't feel the need to ask them for a description of their exact process. Based on prior Campagnolos, I am confident in their abilities to prep the metal properly for powdercoating. The only question will be if I like the resulting surface appearance, depending how or if imperfections 'telescope' through the powdercoat finish.
- Art

 

Having a photo of the naked rim would be nice!

 

Well, I should be able to oblige with photos 'in the buff' some time tomorrow..

The shop just called to apologize they can't powercoat them.. The heat causes so much fluid to exit the pores, it's ruining the coating. Must come from decades of various LHM leaks into the porous metal..

(At least my worst fears were NOT realized when I heard their apologetic tone... that they ruined the rims! Aagh.. )

So - onwards to enamel paint! ..or does The Maserati Hive Mind have other recommendations?
- Art

 

In my best Dr. Seuss tempo ...

I will not gloat I will not gloat I will not gloat. No really I won't.

Plenty of us have struggled with these old rims Art. Welcome to the club.

I have heard word of pre-heating them several times but I can't say I know of any successes.

 

Krylon Dull Aluminum, you’ll be surprised how close a match it is to Original.

 

OK Guys---No choice but to interject:
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First attempt, abject failure as expected!
Then we went to war, per above:

Soda blast; get Dupont involved directly; perfect!
Even had gentle over-spray run on two, to confirm originality!

Color. Simple; from my 996 TT's alloys.
ALZWL.

Regards.

 

Well your photos are pretty blurry but ... your rims look pretty benign in condition. What were their recommendations for treatment and primers?
Bare hands on them not a great idea though.

 

Be honest with you---like Art, never even bothered with the protocol!
Just made it clear they would have to continue until we were all happy!

Part and parcel of the bare metal respray; if you know what I mean!