Which colour matches aluminium castings the best?

E28 technical advice asked and given! Troubleshooting, modifications and more.
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szacsi72
Posts: 286
Joined: Nov 13, 2022 3:41 AM
Location: Hungary

Which colour matches aluminium castings the best?

Post by szacsi72 »

The cast aluminium parts on my M30 are... old. They are not very pleasing visually. I've cleaned them, tried blasting them.. In either way, they are quite dull and ugly. So, I will spray paint them.

However, I really hate the look of regular silver spray paint. In my country we call it "kazán ezüst", and it's that basic flat, white-ish silver you will find everywhere.
It looks like poop, in my opinion.

Did anyone find a colour that matches the original aluminium colour better?
I'm thinking maybe RAL9007 maybe...?

Thanks for your input.
jimoreno
Posts: 1532
Joined: Aug 30, 2007 9:31 PM
Location: Land O Lakes, FL

Re: Which colour matches aluminium castings the best?

Post by jimoreno »

I painted mine with a paint that has aluminum paste in it. It's from a company called Seymour paints and it's called Alumi-Blast. Eastwood also has their own version called Aluma Blast.
This is how my parts turned out. You can also use a matte clear to kind of seal them as the finish is kind of rough just like aluminum.
Image

https://www.seymourpaint.com/product/ca ... can-12-oz/

https://www.eastwood.com/ew-aluma-blast ... 12-oz.html
Mike W.
Posts: 27181
Joined: Feb 12, 2006 12:00 PM
Location: California Whine Country

Re: Which colour matches aluminium castings the best?

Post by Mike W. »

Cool, the site's back up!

On color, it's complicated. Different castings, mostly due to texture, have a vastly different color and appearance. Heads for instance tend to be much brighter and smoother, intakes not so much. Just pick one you like and go with it.
gadget73
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Joined: Nov 22, 2017 10:30 PM
Location: New Jersey

Re: Which colour matches aluminium castings the best?

Post by gadget73 »

I've had pretty good results out of the Duplicolor Cast Coat Aluminum, but no idea if its available where you are. Like Mike said, the texture determines the end finish but the CCA wasn't obnoxiously bright silver. Someone actually asked me where I found an NOS intake and valve cover, so I guess it fooled at least one person.
EuroShark
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Joined: Feb 12, 2006 12:00 PM
Location: Colorado

Re: Which colour matches aluminium castings the best?

Post by EuroShark »

Vapor honing is the best option if you're trying to restore aluminum parts to look like new. It's a wet media blasting process that cleans without damaging the surface, and if done correctly will leave a mildly polished finish that is less susceptible to corrosion. Another benefit is that since it's a surface treatment and not a coating on top of the aluminum, you don't have to worry about eventual flaking or peeling.

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szacsi72
Posts: 286
Joined: Nov 13, 2022 3:41 AM
Location: Hungary

Re: Which colour matches aluminium castings the best?

Post by szacsi72 »

Thanks guys.

Last time I used RAL9007 but it's still way too silver for me.

Yes, vapour honing is nice but unfortunately noone nearby does it. The closest I could try was soda blasting, but I wasn't satisfied with the results.
Shawn D.
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Beamter
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Re: Which colour matches aluminium castings the best?

Post by Shawn D. »

gadget73 wrote: Jun 17, 2024 8:19 AM I've had pretty good results out of the Duplicolor Cast Coat Aluminum, but no idea if its available where you are. Like Mike said, the texture determines the end finish but the CCA wasn't obnoxiously bright silver. Someone actually asked me where I found an NOS intake and valve cover, so I guess it fooled at least one person.
2nd vote for DE1650. Here's how it came out on the intake on my AMC Spirit. This is after 8+ hours of drying outside above 70°F:

Image
stuartinmn
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Location: Minneapolis

Re: Which colour matches aluminium castings the best?

Post by stuartinmn »

I used to use Krylon Dull Aluminum spray paint but it doesn't appear they offer it anymore.
Another possibility is various vintage car part suppliers sell a silver spray paint called Argent - it's mainly used for painting steel wheels but it's also fairly close to the color of raw aluminum castings. One source in the US is Year One but there are others. I don't know if it's a possibility for someone living in Hungary, though; there may be European part suppliers that sell something similar.
szacsi72
Posts: 286
Joined: Nov 13, 2022 3:41 AM
Location: Hungary

Re: Which colour matches aluminium castings the best?

Post by szacsi72 »

I've just found the spray can that I used for an M50 I've rebuilt for a friend of mine, and it's RAL9007.
It looks like this:
Image

Thinking about it, it actually matches NEW cast aluminium really well. It's just that the casting next to it is old and dull... making the painted parts appear too bright.
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