One of the first Eastwood products I ever purchased was a Golden Cad replica paint kit for a Volkswagen I was resto-modding. I wanted to match the original yellow chromate plating finish on some engine hardware that had corroded. I didn’t need it to be concours-perfect, it just needed to look right when the hood was open.
It worked well for that project, and I used it on several underhood pieces with great success for a novice. But I noticed that on brackets requiring nuts and bolts, I had to be careful not to crack and flake the paint. It could also be difficult to balance the green and red tints, as well as achieve the right gold transparency.
Now, as I work through a more factory-correct restoration on my 1993 Range Rover, I’m torn about how to deal with restoring the yellow zinc or gold cadmium finishes once again. If budget were no object – and believe me, it is – I’d have all my original parts replated or replace them. Of course, many of the parts that were originally plated this way are no longer available new. And some of them, like the fuel injector rail, are available from aftermarket suppliers but not with the original finish. And the money I might spend replating them will be needed for so many other things on this major endeavor.
All of this got me wondering if it might be possible to replicate the look of gold cadmium plating with powder coat instead of paint. After all, powder would at least provide greater durability than paint. And it might even offer the opportunity to get a more accurate replica of the plating finish as well. Last week I took the plunge and tested my theory. Here’s what I got.
What is Gold Cadmium or Yellow Zinc Plating?
If you’ve ever paid attention to all the different finishes on a car, you’ve probably seen shimmering gold hardware. This is most likely a zinc-plated steel part with a yellow chromate finish for added corrosion resistance. On older cars, this may have been cadmium plating instead of zinc, also enhanced with a chromate layer. Due to its toxicity, cadmium is far less common on modern vehicles, however.
Whether it’s zinc or cadmium hardly matters, as the chromate layer tends to make them look the same regardless. If you examine these plating finishes closely, you’ll notice there are three distinct colors at play. The base is a transparent, non-metallic yellow tone that can vary from a subtle platinum/gold to almost brassy. Their density and patten are extremely random, the various chromate elements pooling and settling unpredictably as they dry. Above that are transparent swirls of red and green. No two parts ever truly look identical from car to car.
Replicating these three elements is not easy. The Golden Cad paint kit remains popular today because Eastwood figured out the basic elements a long time ago. The trick, however, is in applying them convincingly, and powder only makes that more difficult in many ways.
Hacking the Gold Cadmium Look with Powder Coating
Determined to at least make a go at replicating the plated chromate finish, I grabbed a sacrificial part for my experiment. The power steering pump bracket is a fairly universal part for older Land Rover V8s. If I screwed it up completely, I could easily find another. I had already blasted mine to bare steel for refinishing, so it was ready to go. I just needed to figure out my recipe.
I would need to apply light coats of whatever gold, green, or red I chose. But I also wanted to fully coat the bare metal to prevent corrosion from starting. I chose to lay down a base coat in a highly reflective silver. I grabbed a couple different gold powders in search of the right tone and translucency. For the green and red tones, I also chose transparent versions to get the candy-like finish.
After several rounds of experimentation, here is what I settled on:
Step 1 – Reflective Chrome
I applied single-stage reflective chrome powder to the entire part with the Eastwood PCS-250 powder gun set on the high voltage setting. This application then cured for 20 minutes at 400º F.
Step 2 – Translucent Gold
While the part was still hot right out of the oven, I applied a light to moderate layer of translucent gold powder. For this application, I applied no electric current at all, using only the air pressure from the gun. This “hot flocking” technique prevented heavy build-up on the edges of the part from the Faraday Effect. Once covered, the part went back into the oven for another 10 minutes at the same temperature.
Step 3 – Translucent Mahogany
Rather than choose a more candy-like red, I went with the slightly darker transparent mahogany powder for the red component. In looking at a lot of yellow chromate parts, the red simply looked a bit deeper than a typical red. This layer of powder was also hot-flocked immediately and applied without any current. The key to applying the red is to do so randomly and sparingly. It tends to gather in puddles but not cover the entire part. As soon as the red powder was sprayed, the part went back in the oven for another 10 mintues.
Step 4 – Translucent Green
A green tone tends to cover the entirety of most chromate-plated parts, so translucent green powder was the final layer. As with the red layer, no current was applied while spraying. A very light but uniform coating was laid down across the entire part, with random areas getting slightly more coverage to create the random effect. With the final layer applied, the entire part finished for 15 minutes in the oven.
Step 5 – Knock Down
After cooling down, I looked at the fully coated bracket from several angles. The overall effect was convincing, though it leaned toward the lighter platinum end of the gold scale. A bit heavier application of the gold powder would be more ideal. The only thing was off for me was the sheen. It simply looked too shiny. I knocked down the shine with a medium (red) scuff pad and very light pressure. This still allowed the various transparent layers to shimmer while eliminating the unnatural clearcoat effect. Using a fine (grey) scuff pad might be the only adjustment I’d make to this final step.
Happy with the results, I’ll be refinishing the rest of my original yellow chromate engine parts using this powder coating recipe. It’s not a true replacement for replating, but should give me a generally correct appearance, great durability, and enduring corrosion protection.
Resources for This Project
- Eastwood HotCoat® PCS-250 Dual Voltage Powder Coating Gun
- Eastwood HotCoat® Single Stage Reflective Chrome Powder
- Eastwood HotCoat® Translucent Yellow Metallic Powder
- Eastwood HotCoat® Translucent Mahogany Powder
- Eastwood HotCoat® Translucent Green Powder