Full Case Restoration Example

The Gruen automatic that came with a movement covered in my previous post had a case that had clearly seen better days. It was originally chrome plated, and while chrome plating is remarkably durable and scratch resistant when treated well (for a great example of how well chrome plating can hold up, see this Sovereign watch), this Gruen had been subjected to some hard wear, and it was heavily scratched, with the chrome plating fully worn through in many spots, as you can see in the photos below:

Now, I generally hesitate to refinish vintage watch cases. The wear on the case, as well as patina on the dial and hands, tells the story of a the watch and is actually an important part of its vintage charm. When you refinish the case, you lose some of this history, along with the originality. Still, there is a point, which may be different depending on you own personal taste, beyond which a watch case becomes so battered that it crosses the line from “vintage and charming” to “old and ugly.” For me, this case had definitely crossed over that line, so a restoration was in order.

So, having decided to move forward with the restoration and removed the crown tube, the first step was to strip the case back to the brass. One of the virtues of chrome plating, its hardness, becomes a headache at this point, as it is quite tedious to remove manually by sanding. Instead, I use an electro-chemical stripping process. This takes the chrome layer off completely in less than a minute.

The case after electrochemical chrome stripping. Notice that there is still a thin layer of nickel plate remaining. Nickel is commonly used as an under-plate for chrome to help with adhesion. Fortunately, unlike the chrome, this layer is easy to sand off.

With the chrome out of the way, it was time to bring out the sanding sticks and start working on sanding & polishing out some of the many, many scratches on this case. With brass cases, I like to start with 400 grit sanding sticks, and then move through a couple of finer grits, ending with 1000 grit. I also have a miniature tabletop belt sander with a 1” belt, but it tends to be pretty aggressive - even with a 2000 grit belt installed - so I generally stick to hand sanding brass pieces.

This case had some pretty deep scratches in spots, so I wasn’t able to eliminate them completely - it’s important not to overdo it when sanding out scratches as you can actually start to alter the design features of the case, so compromise is needed. In any event I personally think it’s fine, possibly even desireable, to leave some imperfections on the surface of a vintage watch case.

After sanding, it was time for the polishing wheel, starting with a firm buff using Dialux Yellow polish, and finishing with a soft buff and Dialux Red (a.k.a. jeweler’s rouge).

The case after sanding and polishing. There are still some visible nicks and scrathes if you look closely, but the overall appearance is much cleaner.

With the brass case fully prepared, the next step was metal plating. Unfortunately, re-plating in chrome was not an option for me. The chrome plating process is quite toxic and carcinogenic, to the point where chrome plating is being phased out or even banned, and it’s not something i’m willing to mess with, even if I could get my hands on chrome plating solution (which I can’t). Instead, when I need to re-plate chrome items I use rhodium. Rhodium plating is attractive and reasonably durable. It produces a finish that has a more neutral cast than chrome, which has a slighly blueish tint, but otherwise provides a similar aesthetic.

So, after adding a nickel under-plate, and then plating in rhodium, here is the final result:

The fully restored case, with fresh rhodium plating applied.

If you found this process interesting, check out the Learning section of my site, where I go into more detail on case restoration and electroplating, as well as a number of other watch restoration topics.