Protecting a brass watch body from sweat and dirt induced corrosion

[Clang!]

Here's the conundrum: I like Timex wrist watches, but most of them are brass cases finished with plating or anodizing. The finish lasts about 6 years under normal weekday wear and tear, and then pinpoint corrosion starts. Within a year or two, the corrosion has reached the waterproof seal under the caseback. You can figure out the rest.

Any recommendations (coatings, treatment, etc.) to preserve the finish or stop the corrosion once it starts? I've heard of Renaissance Wax, and there are touch up laquers for brass instruments, but I'm hoping there are finishes to protect against contant use.

 

[ron_m80]

Fingernail clear coat, or so I have heard. Never tried it myself.

 

[skyhorse]

You can buy a band that covers the bottom of the watch,it will do the trick.

 

[Piso Mojado]

The case is brass, the case back is stainless steel, and the problem is galvanic corrosion. According to Wikipedia:

Dissimilar metals and alloys have different electrode potentials, and when two or more come into contact in an electrolyte, one metal acts as anode and the other as cathode. The electropotential difference between the dissimilar metals is the driving force for an accelerated attack on the anode member of the galvanic couple. The anode metal dissolves into the electrolyte, and deposit collects on the cathodic metal.

The electrolyte is the salt in your sweat, which is why the watch only corrodes when you wear it. One solution is to protect it from your sweat by putting it on a bund strap.

There are a variety of patterns. Get one with a pad big enough to protect your watch, but not too big.

You don't need Chicago screws for a Timex unless you like the look.

 

[Drudge]

I think the patina that builds up on brass timepieces looks amazing but thats just my opinion.

 

[Clang!]

The case is brass, the case back is stainless steel, and the problem is galvanic corrosion. According to Wikipedia:

The electrolyte is the salt in your sweat, which is why the watch only corrodes when you wear it. One solution is to protect it from your sweat by putting it on a bund strap.

I had not considered galvanic corrosion. I would agree with you except that I don't think it's the stainless caseback that's killing it, but the plating on the brass. My current watch (Timex T2e561) has a "silver tone" finish and is probably nickle plated. High phosphorus nickle alloys are commonly used in ENP coatings for acidic and abrasive enviroments, so that's what I figure Timex uses. It is somewhat more cathodic then the brass, so once the coating wears through, sweat (electrolyte) attacks the brass via galvanic corrosion and eats it out from under the plating.

I'll see if I can't find a bund strap to prolong the plating on the back. If I can slow down the plating wear, I can prolong the time till galvanic corrosion starts. Once that starts, I will use nail polish or a similiar fluid to fill any corrosion pitting to keep the sweat away from the exposed brass.