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You can spend the money to have it "chromate washed" (not plated) following new zinc plating, but it won't last. It will slowly turn a dull grey from oxidation, just existing in the air.
You could get it done, then shoot it with a protective clear coat; but the clear coat would yield to the heat and petroleum vapors of the engine compartment....unless it is just for "show".
Use several grades of jeweler's polish....it will get you a very shiny housing....clearcoat with automotive heat resistant. I have gotten 5 year out of the polished engine case on my Harley....clean with soapy water on a cotton cloth monthly.
The carb isn't visible as I'm running the stock air cleaner. I was just wondering if plating would provide a level of protection and if so, was it worth doing while it's off and being rebuilt.
The 'protection' is provided by the zinc plating on those parts. The chromate wash is simple, adds a bit more protection (in the short term), and gives it an attractive gold-ish color.
For 'general-purpose' vehicles that like to show similar to stock, the outer surfaces of the carb can be painted for better protection. Eastwood offers some stuff called 'Carb Renew' or you can gin-up your own method for obtaining the chromate 'look', while protecting the metal surface.
There are folks that have disdain for painting carb bodies; but folks have been doing it for many years without adverse issues. Most marine carbs are painted.
Here's an example of painted carbs on an Olds J-2 tri-power intake::
Last edited by 7T1vette; Nov 12, 2019 at 07:22 PM.
This is the stock quadrajet on my 68 L 36. It was done by Cliff Ruggles a few years ago. No extra plating like you see on a lot of the restored carbs. I think it looks pretty good.
Do you use the stock air filter assembly? If yes, then I would not waste the money on a finish that is not visible.
On a side note, I restore vintage Japanese motorcycles and vaporblast the carbs when rebuilding, leaves a nice satin finish.
This is off a '74 Kawasaki H2 750
I also restore and work on vintage Japanese bikes and can attest to the vapor blast.......it is an excellent way to bring aluminum back to being bright......but, these carbs on these bikes are visible.
The above H2 carbs are very porous.....my ultrasonic does not clean them well but later model stuff such as CBX stuff brightens right up........I have ultrasonic clean old Carter AFB's and WCFB's and they brighten up well......
I think Zinc plating is pretty cool but as stated, if you can't see it, then why? Worry more about how the carb functions rather than how it looks.
I have also painted carbs but it takes a ton of taping and razor blade trimming.......usually do this for boats and jet skis to ward off corrosion.
I do not know, but suspect that a zinc plated carb body can be refreshed with a vapor blast treatment at low pressure, so that the surface is cleaned/brightened without removing anything but the oxide layer. If true, it could then be dipped in a chromate wash to give it the original color, as well. But, as I stated in prior post, it won't last many years. I suppose that newly plated chromate-treated parts could be clear coated with oil/fuel resistant paint to keep it looking good for a much longer time.
