Bumper Modification

[bird 60]

I also like the Idea, especially with the '60. The ends of the center piece is hidden & doesn't look quite right. If it was me, I would place the bumper guard mounts closer together, in the center. However, mine is going to stay the way it is as it looks like new,& no damage. The cost for us to fill holes & re-chrome would be around $2-3 thousand. How much $ was the end result Del.?

Chris.....From OZ.

[Y-Blokkah]

I learned more about plating in the 10 minutes it took me to read this thread than in the previous 20 years of my life.

I’ve never had a problem with nickel and chrome processes because they were cheaper and to me they looked “factory”.
But now, I’m a grumpy old coot and I’m liking that hexavalent method more and more.
After all, the 59’s gonna be my last restoration/rebuild, right?

I’ve always thought on a 55 Crown, the two step process on the bumpers and grille better matched the half acre of buffed stainless you put back on the car.

With no real stainless side trim on a squarebird, going all the way with hexavalent seems to make more sense.

Oh, and pulling off those bumper guards was the right thing to do. It looks seriously kick-*** now.

[del]

Total cost was $1450 - $100 to fill the divots, $1350 for remaining corrosion cleanup and re-chroming.

[simplyconnected]

I'll try to summarize the chrome plating process for both pot metal and steel.

We always used hexavalent chrome. Today, it's nearly outlawed by all corporations. I say 'nearly'. The chemical process for neutralizing the potassium cyanide is expensive. Plating tank samples must be submitted to the EPA to ensure none of it enters the ground or waste water system. Hexavalent chrome is carcinogenic. Trivalent chrome is not.

Trivalent chrome is widely used today. The trained eye can see a blue tinge in it but it closely resembles hexavalent chrome.

The old process involved plain old nickel plated on steel but it tarnished to a golden color. Everyone had to polish it get the tarnish out.

Then, we used the two-plate process: Nickel plate then (hexavalent) Chrome plate. Chrome is so thin, you see the bright nickel through it. The purpose of chrome is to stop nickel from tarnishing.

In every plating process where the part is under high visibility, the base must be polished to a mirror shine because every tiny scratch will show through. For example, we polished the top side of our bumpers but not the bottoms. I takes too long to do all the surfaces and nobody ever sees the bottom or insides.

"Show Chrome" is a three-plate process. The metal must be polished first. If the pot metal had pits, they were drilled or ground out to get down to base metal. Steel must be rust free. Since copper will stick to just about anything, this is the first plate in either, pot metal pieces or steel pieces.

After copper plating, pot metal pieces still have divots from drilling out the rot. Lead solder is used to fill the divots because it sticks so well to the copper plate. Then the pot metal piece is smoothed, polished and re-copper plated.

After polishing the final copper plate, nickel is plated on either the pot metal or steel piece. Again, another polish, and finally hexavalent chrome is plated.

There's your three-plate process - copper-nickel-chrome and it's done as 'show chrome' on either pot metal or steel.

Notice the number of times we polish. In a plating shop, the polishing room is larger than the plating room and polishing requires more people. That's why plating is expensive.

There's more to this... Plating does not warp metal because the plating process is done while submerged. Sandblasting warps metal. Another method of removing rot is by chemicals like sulfuric acid, etc. Again, the plating company must not use chemicals that will dissolve the part. This happened to me on radio knobs with that little spring steel piece inside. The little piece was GONE on six of them.

When you bring your pieces in, COUNT THEM. Your order may be mixed with other work. A good plating shop will not lose your pieces and they will offer a warranty. - Dave

[Y-Blokkah]

Coolness! Thanks.

Back in the early 90s I tried to get my 56 Merc headliner a/c vents plated.
The pot metal surrounds were easy enough, but the plastic louvres were another story.
“Nobody plates plastic” is what I heard again and again.
So how’s it done? It isn’t just paint, is it?

[simplyconnected]

Ernie, think about it... We've been plating plastic since before model cars came out.

AMT was situated in Troy, Michigan, next to my city of Royal Oak. Many of the women in my area worked there. It was a plastic injection mold company but they also plated those 'trees' of parts that included the chrome bumpers, hub caps, etc., for model cars. We had to scrape the plating off for the glue to stick to the plastic. Most plastic parts today are done using an ion-deposition process. Some, you can see light through the chrome.

Other plastic model trees included clear or colored parts like windshields and tail lights. The women would bag the parts and box the whole thing with instructions. They made hundreds of model cars with features that looked exactly like the real thing.

One of the plating companies by my house displays a glass Coke bottle that they chrome plated to show, they can chrome just about anything. They start with a cleaning 'strike', then another strike that will etch and adhere to glass, then another strike that copper will hang on to, etc. At Ford, we nickel test-plated the aluminum rotor housing of a Mazda rotary engine. During the reliability tests, the plating separated from the aluminum because of the different expansion coefficients.

One of my buddies had his stainless grille chromed. It looked nice until the plating started peeling off. Again, different expansion coefficients. - Dave

[Y-Blokkah]

Thanks Dave,

My response to him was similar as I brought up plastic model chrome parts, but they had said that it needed to conduct electricity and plastic doesn’t so they used some other process that “looks like chrome”.
I guess I knew he was wrong, but other than on that Merc, I’ve never really had plastic that needed chroming.