Flash chroming SS moldings

[Bob Hoffmann CLC#96]

First, do any of you agree with me that most SS moldings had a flash of chrome applied when new?  No copper or nickel, just chrome. As soon as the buffing wheel hits an original molding , the color changes & it looks different! So.... why do these chrome shops look at me like I'm crazy when I ask them to flash chrome the parts they've just polished for me??? Is it another example of what the factory does & these guys just can't duplicate? Please enlighten me!   Bob

[The Tassie Devil(le)]

G'day Bob,

The problem I see is that Stainless Steel isn't Chrome-platable, but then, I could be wrong as normal.

It is the Nickel Plate coating that gives the finished article its' colour, and the Chrome Plating is the finish.

Bruce.

[John Washburn CLC 1067 Sadly deceased.]

Bob,

GM was noted for Flash Chroming the Stainless Trim. I've been lucky and just had folks carefully polish the chrome, just enough to polish, not take the chrome off.

If you polich through the chrome you can tell the difference.

I have not checked to see if you can still get this done since I figured without the copper/nickel plating this would be easy.

I await comment. Oh, and Bruce, no disrespect, it is possible, althought not likely, that in this instance you could be dead wrong. Civily yours.

[The Tassie Devil(le)]

I await comment. Oh, and Bruce, no disrespect, it is possible, althought not likely, that in this instance you could be dead wrong. Civily yours.   

G'day john,

It is nice being more wrong than dead.

Being dead is so permanent, and hard to correct.

Bruce.

[Roger Zimmermann]

Yes Bob, you are right. Stanless steel is "yellow" when just polished without any treatment; with the flash chrome, it's "blue" like any part which is chromed. This difference of color is evident if you have, like my '56 Sedan de Ville, a NOS front fender molding (chromed steel) and a front door molding (polished ss steel).
In Swizerland too, people look at me like I would come from the moon when I ask for a flash chrome. Some platers try it, some don't want to hear about that.
I'm also interested to know how this process was done at the factory.

[Wayne Womble 12210]

It may be that you are asking for the wrong process.  In looking through my Electroplating Engineering Handbook, there is no mention of plating SS, but there is a process of electro polishing, called Bright Dipping.

To Smooth and prevent pitting on SS the solution consists of :

29.5% HCL  sp. gr. 1.16
40.0% H2SO4  sp. gr. 1.84
0.5%   HNO3   sp. gr. 1.43
5.5%   TICL4
24.5%  H2O

Dip at 165 Degrees for 2-5 min.


Another solution for Austentistic SS is:

2.5% Nitric Acid.  sp. gr. 1.42
7.5% hydrocloric acid  sp. gr. 1.16
1.0% Rodine 45
Add 10 l. of toner No.1 per 100 gal of bath.

dip 3 min @ 205 deg.

[John Washburn CLC 1067 Sadly deceased.]

Wayne,

The reference for flash chrome:
Flash Chrome Plating
Flash Chrome Plating is a thin (.001" to .0007") deposit of chromium. Despite its thinness, it still provides an excellent barrier to corrosion while maintaining most of the beneficial properties of conventional Hard Chrome Plating.

Seems that industrial folks plate hard chrome and Flash Chrome. Sounds like it is plated to me, but have not found any more details.

[Wayne Womble 12210]

Wayne,

The reference for flash chrome:
Flash Chrome Plating
Flash Chrome Plating is a thin (.001" to .0007") deposit of chromium. Despite its thinness, it still provides an excellent barrier to corrosion while maintaining most of the beneficial properties of conventional Hard Chrome Plating.

Seems that industrial folks plate hard chrome and Flash Chrome. Sounds like it is plated to me, but have not found any more details.

I can find no reference to " flash plating " of stainless in the text book.  However, I did finally find a reference to chrome plating SS.  It says, " The immersion-activating treatment cycle III-1, 5a(2), followed by rinsing, has been used with success for chromium plating on stainless steel automobile parts".  Maybe this is the process that they are talking about when they use the term  " flash chrome".  I am very familiar with these stainless trim pieces. They are very common on the Corvettes that I work on, and I have buffed through my share.

[Bob Hoffmann CLC#96]

THANKS to all who responded. I've taken a test molding to a local electropolishing shop. I have no idea if it's the process I need. I will post as soon as I see the results. Bob

[homeonprunehill]

THANKS to all who responded. I've taken a test molding to a local electropolishing shop. I have no idea if it's the process I need. I will post as soon as I see the results. Bob

04-23-08
Bob, I knoew that I'am a little late in responding, but, when I had the chrome replated on my '38 LaSalle the man at the Plating shop told me that it was a waste of money to have the SS "chromed". He took the SS and polished it to a brillent shine. But, it cost about as much to polish it as if he had "chromed"it. Good Luck, Jim

[Bob Hoffmann CLC#96]

I got my sample part back yesterday after being electropolished. While nice & shiney, it was NOT even close to the factory look. He felt it was not originally flash chromed, but electropolished. I agree. But what was the process??? I made a call to try & contact a retired GM executive but have not heard back. In response to Jim, my moldings are already polished, but I'd like them to look factory as opposed to just polished SS. I'm not even sure that flash chroming the moldings will give the desired look. Still searching. Bob

[Wayne Womble 12210]

Bob,  The Corvette guy discuss this subject from time to time.  Maybe you can get some information from one of them.  This is a  recent thread.

http://forums.corvetteforum.com/showthread.php?t=2006155

[Jeff Maltby 4194]

Bob. What car are we speaking about here ?

Jeffo 49er chapter :<)

[Bob Hoffmann CLC#96]

Jeff, any car that has chromed SS parts on it. The car I'm working on is a 41 Cad. Bob

[Bob Hoffmann CLC#96]

Thanks to Wayne & Southpaw. I've joined both of the forums you sent me. They are both great & I'm waiting for responses. I will post info when I receive it. Regards, Bob

[Bob Hoffmann CLC#96]

OK guys, here are the results. Just picked up the windshield & back glass moldings today. These were SS moldings that had been polished by some other shop & looked yellow.  Now they have the blue chrome factory look that I wanted.  FANTASTIC! The shop that did the work is called Sherm's Custom Plating in Sacramento Ca. 916 646-0160.  Bob

[The Tassie Devil(le)]

So, what actual process did the Shop use to give you what you wanted?

Bruce.

[Bob Hoffmann CLC#96]

Hi Bruce, the work order said chrome only, so I assume that's what they did. To recap, my moldings had been polished because they had been straightened & worked. I think if you had a virgen SS molding as the factory started with, you could just plate it. I had an original molding & compared it to the replated ones. It wasa perfect match. So...... I firmly believe that moldings that have been polished need to be chromed to restore the factory look.  I was at my upholstery shop today. They had a restored 57 Chevy with polished W/shield moldings on it. I put one of my rechromed moldings next to it. Well....... you know the answer. HTH, Bob

[The Tassie Devil(le)]

Thanks Bob,

Bruce.

[Eldorado_64]

I know it's a bit newer, but is or was this process still being uded into the mid 60s? I have done several '64s and never really noticed. I never machine polished but hand rubbed so maybe I never got far enough to remve anything. I did several wheel covers to bring out the high shine of the car surrounds and other polished areas and the really come to a beautifull shine. I know the refinishing polish I used (equal to marine boat polish) is working to take off oxiidised discolor cause I can se the black in cloth as I work.

I did my wheel well moldings and lower rocker pannel trims as well as windows too and they still look as nice but a tad glossier and more briliant then when left in sun for many years.

Brandon J.