Saturday, 3 July 2010

Rust Removal

The question of rust removal has been discussed many times on almost all the fora I frequent. In my limited experience I have found this to be a very effective rust remover-

Yes, that's right, TEA :-). Every time I post this it is regarded as a horological curiosity. So I have decided to show it's effectiveness. I found out about this method on the BHI website. The rusted parts are soaked in a strong brew of tea for as long as required. Apparently, tea has weak tannic acid that is just the right strength to attack rust. when you soak a rusty part in tea the rust dissolves leaving off black wisps into the solution. like these screws-

Only good steel is left behind. Off course, the rusted metal is removed not repaired. So, sometimes you are left with an unusable part. I once soaked a rusty cannon pinnion- centre wheel pair in tea. The rust was removed but they did not snap together again. In this case one would need a replacement part anyway.
So, the subject of my evil experiments is this tiny ladies "Limit of Switzerland" that I
got as a parts lot.This watch is about 17mm dia not including the crown.

The balance swung fine but the train was seized. I decided to go in to practice my
skills (Ladies movements, owing to their size, being much more difficult to work on). Here is what I discovered inside......

The barrel

The escape wheel

The fourth wheel

The barrel bridge

The escape wheel cap jewel carrier,

The key-less works,

.....rust at almost every pivot!

In my four years of fiddling with watches I have never seen anything quite like this. I can only guess that someone used an improper lubricant (Water???) at some point in the life of this poor watch.

So, I soaked all the parts in tea for a few hours, changing the tea once it turned murky. After this I cleaned all the parts in the ultrasonic cleaner. Unfortunately, I neither took pictures of the soaking nor of the parts after treatment.

I was pleased to see that not only does the watch work but it is also keeping time
after this unconventional treatment. The point is that if tea could make this tiny movement work well (with it's tighter tolerances), then it is a very effective method indeed!