clean up and polishing Windshield and rear glass molding

[Sauron327]

The moldings seen polished to a screaming shine are incorrect. Except for one remaining NOS driprail mldg, I've had NOS moldings and they do not look like the pretty polished pieces. I've polished stainless as stated earlier and the evidence of flash chroming is obvious when it's cut through.

[IZRSSS]

Cutting through? I think you mean a white residue. This has more to do with getting the metal too hot and burning the stainless. Screaming shine? The only way to get a screaming shine is to get it chromed. This is why stainless is polished and buffed.

As I stated earlier, flash chrome is foreign to me and it sounds like a fine overlay and not something you would burn through but easily cut through. I don't doubt anyone about flash chrome I would just like to see something that explains the process. Does it mean the same thing as re-chromed or is it a completely different process and finish?

[Sauron327]

That's not what I'm talking about. I've never seen white residue on stainless and I've got a pile of it. White patina is found on the aged anodized aluminum. When one removes the dents as I have and uses various grits of paper prior to buffing a deliniation can sometimes be seen in the finish. It's the flash of which John is speaking. I've never burned the stainless from excessive heat. I'm well aware of buffing techniques from countless cars painted over the years. Common sense. There is a big difference between highly polished stainless and an original piece; that is what I mean by a screaming shine. When you find out all the details and procedures in the flash chroming process kindly post them or a reputable link.

[IZRSSS]

When you find out all the details and procedures in the flash chroming process kindly post them or a reputable link.

 
When the details are found you should see them right here. I'm not the one that knows that's why I asked. This should clear it up for a lot of us.

I'm wondering if its similar to the anodized finish found in aluminum?

If stainless moldings were chromed at the factory then maybe they should have a brilliant shine. I just can't see chrome coming out any other way. Sorry if it sounds like I'm beating a dead horse but it just doesn't make sense. Some say they don't want a brilliant shine but then say it was chromed at the factory. You can't have it both ways. However, once we have "An explanation of the process", it should answer a lot of these questions. Why don't we give it some time...  

[Sauron327]

It's obvious the process is different because the appearance is different. That was also pointed out by John in reply #14. The anodized finish on aluminum is not the same and can be removed differently. Some use oven cleaner and other chems. I never had a reason to. But those I've sold trim to have and then sent it out to be re-anodized. Add that your research work. I'm not overly concerned with all the details but perhaps others are.

[IZRSSS]

Not really sure why you hijacked my question but with all due respect I still want to know from someone that was there...

[Sauron327]

Not really sure why you hijacked my question but with all due respect I still want to know from someone that was there...

 This thread was started by someone else on Dec. 9, 2009 and has had input from various members. It's an open forum. If privacy and one on one problem solving are preferred, an off site discussion is best suited to meet that need.

[IZRSSS]

Not really sure why you hijacked my question but with all due respect I still want to know from someone that was there...

I have nothing further to discuss with you.

[L78 steve]

All I can add is there is definitely a coating of something over the raw stainless on front and rear window trim.

[IZRSSS]

I assume this is what John is referring to?
 
http://www.finishing.com/283/70.shtml

I digress...had no idea chromium in its natural state is clear.

[JohnZ]

I digress...had no idea chromium in its natural state is clear.

Here's the short version:

"Show Chrome" (not seen on factory parts like bumpers) is a 3-step process - copper plate, polish, nickel plate (that provides the "silvery" color), polish, then chrome plate (chrome is clear, provides the "shine", and protects the underlying nickel from oxidation and pitting).

"Factory Chrome" omits the copper-plating stage - nickel is plated directly on the polished raw steel part, then it's chrome-plated.

"Flash-Chrome" is only the final clear chrome plating (about a half a thousandth of an inch thick); used on polished stainless steel trim parts to protect them from oxidation.

[IZRSSS]

I feel more confident about discussing this process with would be platters. As I mentioned earlier, this term was totally foreign to me and now it all makes sense.

I'd give just about anything to download that brain of yours.  I like so many others have followed your responses to everything GM. You are a wealth of information and we can always count on you.

Thanks again John!

[m22mike]

This has been a very interesting thread, and a great chance for some to learn about something they knew knothing about.
There is some good information in Jeff Lilly's book. "How to Restore Metal Auto trim".
 In his book he states that GM SS trim has been flash chromed since 1957 ! I believe it to. They also use a 57 Chevy wheel cover as a test piece, and go into detail on how to remove the flash chrome layer using a muratic acid solution.
  As stated in this thread already, when you break through the flash chrome there appearance of the two finishes is drastic.
I have had limited success with GM SS trim when I remove all the FC. I have found that the base metal is not of very good quality, sometimes even porous, and it flat will not come up to a nice bright luster no matter what you do.
 A few years back I polished some 64-65 Dodge trim that was not flash Chromed. It looked like jewelery when finished. I could tell there was a big difference in the quality of the sheet stock used ?
 On very nice used trim with little or no deep scratches you can get away with some wet sanding, 1000- 2000 grit.
If you ever do this you will notice the chrome is very hard and progress is slow, and for you guys that get it, as you cut into the base metal, it is like sanding filler compared to the FC on top.
 Allot of trim I see has been damaged from handling after it has been removed from a car. I like to bundel it up with tape to keep it from banding together.
 I carry a piece of Camaro trim with me to cruise nights that has half the FC sanded off. Used it several times to prove a point.

Mike

[sam]

Mike as always you are the Professor!