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the chromium in a nickel-chromium plating process is clear...a chromium layer over copper would be copper-colored...


epi

When did Chevy stop nickle plating? When they stopped all plating in 1942 for the war years.

The 1952-53 cars that had the Korean chrome (all exterior chrome except bumpers) did not have nickel under the chrome.The chrome was applied over the copper.To protect the chrome a clear lacquer was applied.After a few years the lacquer broke down, exposing the chrome, and causing it to flake off.After the chrome was gone and the copper exposed it turned brown/green.Chrome is not clear - its "chrome" colored.

From at least 1933 and up I can't recall any nickle finish.Only chrome or stainless.

1934 & 35 trucks had nickle on interior door hardware and park brake handle. Chrome on insturment gauge trim.

The 1934-35 cars had chrome plated door and window handles.

Thanks Ray, Gene, I understand Chromium is not a color per se' but a metal, I don't ever recall a Clear metal (transparent), even though I studied Metallurgy at Texas Tech..rather than at A&M.
It was my understanding at the time that Chromium electroplated over nickle is more durable than when it is electroplated directly over copper because copper is so ductile. After watching the process an several shops, it appears to me that the electro-chemical process is pretty straight forward, the beauty and duriability is in the skill exhibited during the cleaning,preperation and polishing.

the nickel plate is usually deposited about a thousandth of an inch thick, then the chromium at less than ten-millionth inch thick...I'd always been told that, at that thickness, it's pretty transparent...


epi

At that thickness the Chromium is probably 40 to 100 molecules thick. The molecules aren't very large.

macky,

yeah, not too thick, but still...at 40-100 molecules, that might be enough to be opaque, or at least obscure...what do you think?..


epi

Once again Chatter has taught me much more than just the answer to the original question.

Hope this discussion continues with some more information...

Actually not much light of any wavelength will penetrate a layer of Chromium that is deposited by the electro plateing process, that is why it is so effective the more it bounces around and is reflected the less transparent the metal appears, and the more shiney it is, isn't that what makes the shine, reflected light of all wavelengths? Just a side note: Silver reflects more direct light than a equally pure layer of Chromium so why don't we silver plate our bumpers?

macky,

because the silver, unlike chromium, tarnishes easily...

I happened to be chatting with a friend today who is a metallurgist & nuclear physicist...he agrees with you that some, but not much light would penetrate a normal layer of chromium plate...

so, that got me thinking: many nickel-chromium electroplate processes use a thicker, first layer of semi-reflective nickel, followed by a thinner, highly reflective layer of nickel, before the chromium...

and, if the chromium were completely opaque, it wouldn't matter what underlying layers were applied first (colorwise, that is...the copper would still be needed to give a smoother surface)...

so, for now, I think I'll amend my statement: chromium is not clear, but translucent...it is inherently shiny metallic, but also relies on nickel for what we expect & like in an object that has been "chromed"...

I learn something new everyday...


epi

That is the name of the game making your stuff shiny, and durable. Physics and Metallurgy and electrical processes, hardly anything is "home-made" anymore, just think about it, If Henry **** had of been an mechanical engineer or perhaps a Liberal Arts grad, maybe just maybe he would have had a overhead valve, four cylinder, Faunce Green model "A" Sedan with a Dunsmire Grey Wheels, and Golden Yellow stripes! or maybe even a Paul Revere Green coach with a rear fuel tank and a Stewart Warner Vacuum fuel pump!

Engineers make things happen! and I don't mean drive trains!

Hey Dudes! Go here: http://freepages.pavilion.net/users/nickfull/chrome.htm

Kepi:

I sure enjoy reading YOUR posts. They're informative. A guy can actually

learn something reading what YOU write. (I left plenty of room in-between

the lines for folks to fill-in what they'd like!!!)

Bill.

interesting link, dog...

I didn't have a chance to read it thoroughly, but it does seem to suggest that it's the addition of barium (barium acetate & acetic acid) that makes "black chrome"...this was a question that came up earlier in this thread...


epi

JYD, your link is great...seems like this guy is also saying anyone can chrome their own stuff at home. This might give the EPA a heart attack...

Maybe the local club here (AACA) can get together and have a chroming party instead of a BBQ...

Glad that you liked the link. If you do a search on Google you will find a lot more information on nickel and chrome plating.

Of course we, the buyers, don't really know how many 'steps' were used and what thickness applied...until much later, after the warranty has expired...

Makes you want to watch them do your parts….

"Makes you want to watch them do your parts…."

Especially if you take some very rare and irreplaceable parts to your local plating shop!

years ago, I had a buddy (now deceased) that owned a plating shop...one day, I called about some parts he was doing for me and he said that they were all ready, except one...I asked why, and he replied that it was momentarily lost...down in the bottom of the vat...seems like it happens from time to time, as things get bumped off the tree...he had to go "fishing" to find it...

if the platers aren't on top of things, they don't even know a there may be a problem with a item until the piece is damaged or even disappeared (if it's the strip tank)...I lost one irreplaceable brass strip this way...only a few minutes too long in the strip tank and nothing left but the hook of the tree when he pulled it back up...ouch...


epi

And.......that happens way more often than we would like too! I know a dude that lost a rare passenger side door ashtray out of a 1932 cabriolet that way. The local plater didn't know what kind of metal it was so he dumped it in his strip tank anyway. The part was stripped alright....there was nothing left of it!

I have yet to be in a large industrial sized chrome plating place that was organized enough to be able to keep track of all the thousand of different parts that come and go, There must be a black hole somewhere that has jillions of lost freshly plated parts in a big old pile.......I have gone with my brother and he always really get involved with hunting every part that he takes in, sometimes they get out of order when one part fails to pass final inspection before polishing and has to be recycled back through the process. In short it just looked like a huge mess to me.

Chromium is indeed clear -

One chrome shop to avoid is Superior Chrome in Houston Texas. They destroyed two complete 1940 truck grills, trim and crowns through poor handling, novice boooger welding and poor packaging -

The owner was not willing to accept responsibility and on the one hand said he personally inspected them and that they "looked great" and on the other hand the parts could not even be assembled because of the poor welding that was done on the bars to stabilize them during polishing. Chrome was delaminating and grill crowns were packaged in carboard boxes and crushed in transit.

You are always better off if you can find someone local so you need only be concerned about one neck to grab.

Chrome plating is Chrome metal and is not clear! I wonder where this misconseption originated? anyone know?

That isn't what I have found about Superior Chrome in Houston for bumpers, anyway. I had a couple of bumpers and bumper guards done there a couple of years ago and they did a superior job, packing was really good and we had no problems with them. ( they are local to us)
They picked the bumpers up at the VCCA swap meet in Grand Prairie and then shipped them to me in Midland for a very reasonable price. One bad job is just one bad job, just the same as one good job is just one good job. You should always try to do business with the locals even if Vendors on the left Coast are nearly all very over priced.
(IMHO)