Galvanic Corrosion?

[steadyflow]

I know there has been a lot of discussion in the past about the benefits of 904L vs other steels but this post is a little different; I have been wondering about how the watch companies get around dissimilar metal corrosion in the long term?

When two dissimilar metals (say gold and steel for example on a DJ bracelet) are in contact with the presence of an electrolyte (sweat for example) then the less noble metal will sacrificially corrode. Do any of the older bi-metal watches show any form of this corrosion?

How would the caseback of say a DSSD do considering there is titanium next to the 904L, do watchmakers have some trick up their sleeve to minimise this kind of thing? As a subsea NDT inspector by trade I am quite interested in this kind of thing (yeah, i'm a little sad....)

[Tools]

A lot of study has been done on Titanium and Stainless susceptibility to galvanic corrosion because of it's common use in implants..

Since it is considered very unlikely in implant use, it is even more unlikely in a Rolex case back, especially if some minimal maintenance is taken..

[Fredrik]

Have a look in a table of the electrode potentials of different metals and you will notice that titanium and stainless steel(at least 316) is very close. They are also considered quite noble so I do not think you get much between gold and stainless either.

[steadyflow]

Interesting, cheers guys.

[perpetual92]

Especially during the summer or near the ocean I always wipe my watch down at the end of the day (or wash it under water if in the ocean or a pool) with a semi wet paper towel and let the watch air dry. I also remove the bracelet at the end of the summer to really clean it, the case (especially in the lug/case corners) and install new springbars.

Rust around the lugs can be common but easy to avoid (unless your profession is with the Coast Guard) with proper care in the older stainless Rolex watches. When I see rust on a Rolex; its a shame on the owner for avoidable neglect.

[dom_]

I have never seen gold and steel corrode, as an example think of the jubilee bracelets and I have seen them uncleaned and untouched for 20-30 years and worn to the point of nearly falling off. But see no signs of corrosion between the metals.

Old Rolex cases do corrode and I have had to laser weld them up and refinish them a fair few times. Most common places are under the back seal and under the bezel.

[steadyflow]

Good reply Dom, i'd love to see a photo of the laser welding being done, bet that's a niche skill when applied to watches!