Shining up some Oxidized Chrome

[Falcon Ranchero]

The chrome bumpers on my '59 Lincoln kit are lookin' a little oxidized; not terrible but compared to fresh out the box chrome it could use some shine. Might be a dumb question but would I just use chrome polish or is there some sort of other way to bring the shine back to those pieces?

[stitchdup]

just yse normal body polish. the chrome polish will take off more of the shine as its usually a mild abrasive polish

[Ace-Garageguy]

There is a problem inherent in trying to polish kit chrome.

Most of it is so thin that you run the very real risk of rubbing through it before you bring the gloss back.

AND...often times, what looks like oxidized chrome at first glance is in actuality chrome that's so thin, you're seeing the base plastic through it, especially on vintage kits.

Proceed with care.

Toothpaste is a very mild abrasive, probably safer to use on chrome than more aggressive polishes made for paint.

EDIT: Here's a little more info on deteriorating kit chrome...

 

Edited February 18 by Ace-Garageguy

[peteski]

Time of some education.

Kit chrome (in 99.9%) of the kits is not chrome.  It is a very thin (couple of atoms thick) layer of aluminum applied in a vacuum over a glossy clear coat.  The process is called vacuum metalization or vaccum metal deposition.  The metal layer is very fragile (as Bill pointed out). If it was real chromium (very hard and chemical resistant metal), it couldn't be easily stripped with bleach or lye.

 

Polishing it (polishing compound is abrasive) will instantly strip the aluminum exposing bare plastic.  Your only options here are to strip it, then either paint it using one of several chrome-finish paints, or sent it out to be "replated" (vacuum metalize) as that service is again being offered. 

Edited February 18 by peteski

[Muncie]

experiment and test - whatever you decide to use, try it out on a piece of chrome that you don't care about.  The abrasives in toothpaste (and some auto polishes) vary quite a bit from brand to brand.  I've tried toothpastes that that turned out to be much more abrasive than a good auto polish.  I kinda gave up on toothpaste so it stays in the medicine cabinet. 

[peteski]

While we don't have a more detailed description of what it looks like other than "little oxidized", I suspect that as Bill mentioned the "oxidized" look is due to the metalized layer simply missing and no amount of polishing will bring it back. In order to polish a solid metal surface, the dull layer needs to be abraded off the surface. That is what polishing compounds do, They simply remove it exposing the clean metal underneath. But here since the "chromey" aluminum layer on the plastic surface is so thin, there is no pristine metal to be exposed.  But at this point you have nothing to lose by polishing it - give a a whirl!

[StevenGuthmiller]

 Very unlikely that anything you try to brighten up the chrome will work.

As others have said, it’s most likely due to thinning of the metal layer, not oxidation, and even a mild abrasive such as toothpaste is still an abrasive and likely to make the matter worse.

Unfortunately, refinishing is probably going to be the only option to bring it back.

In that case, I recommend re-plating.

It’s the only way that you’re going to get a durable finish.

 

 

Steve

Edited February 18 by StevenGuthmiller

[bobss396]

I have some 1982-ish stock cars with dull chrome, it some cases it actually looks good.

It does come off easily just rubbing with a paper towel. Drop the parts in bleach, the "chrome" vanishes in seconds.

[Falcon Ranchero]

Thanks for all the info guys; I might just let them be; it’s not terrible but I just figured if there was a simple way I could just do that but it sounds like I better just leave the chrome alone.

[Rodent]

I don't want to bring up the "paint ain't real chrome" debate, but this '59 Ford Galaxie rear bumper and the two '68 Thunderbird bumpers were in pretty good shape, but the chrome was thin in a few spots, especially the top of the '59. A couple of light puffs of Revell "Chrom" and they look pretty good and will be fine on the shelf. Spazstix clear doesn't seem to dull the finish either. The stuff is expensive, but it works for me for this kind of work. I would never have enough parts to send out to a plater, and that T-Bird taillight is never going to come out anyway.

[dmthamade]

Saw this on LSP forum, looks interesting. read to the end.

Tamiya LP48 Sparkling Silver and MRP-31 Chrome - Painting & Finishing - Large Scale Planes

The Tamiya LP48 looks pretty good when applied over gloss black.

 

Don

Edited February 22 by dmthamade