[crc32]

Hi Forum!

Obviously, bronze watches are more and more getting in style and recently I saw lots of old Komandirskies skinned down, so I thought I'd give it a try myself. A couple of years ago I bought a bunch of them and I still have some parts in spare for experiments like this.

First of all:

DO NOT TRY THIS AT HOME OR WITHOUT SUPERVISION OF A RESPONSIBLE PERSON.

Improper handling of hydrochloric acid (HCl) can seriously damage your watch, your health or cause an angry wife. I am not responsible for any damages caused to your watch, your health or your marriage.

So, this is my starting point, the "before" picture:

Forget about removing the coating mechanically (using sandpaper, a Dremel, etc). Not only does this take ages, it also scratches the surface and will never work thoroughly.

For a start, dissect watch into all its parts. Don't forget to remove all the gaskets, including the one of the crown/stem. If you wish, you can leave the crystal as it will not react with the HCl.

Put all the coated parts (case, crown, bezel) in a plastic container (e.g. a tupperware box). Please make sure that your wife will not need it anymore. I recommend not using it for the storage of food anymore after this experiment.

Fill it with HCl, make sure all the parts are covered completely. Don't fill it to the very top, as it can be hard to carry around afterwards, and a few drops on the parquet will cause some very special effects. (This will transform "angry wife" into "raging wife")

Store it on a place where noone (ie. children, pets, wife, neighbor, anyone else) will not be able to reach it. For sure, noone will assume the liquid you put your watch parts into is pure acid.

IMPORTANT: Do not breathe the vapors of the liquid unless you want to live on disability benefits for the rest of your life.

If you find yourself asking what I require that amount of HCl for - I also use it for cleaing the pool...

Wait and watch the magic happen. After 15 Minutes, the chrome plating is gone completely, turning the HCl green. Be patient, leave it for at least 120 minutes, as there seems to be some binding material under the coating that takes longer to resolve. Another advantage of this process is, you can be sure that the case and the bezel are now free of any dust, dirt or skin scales.

So, here you go, your watch just turned into 18k solid gold. Or brass, that is. If you wish, you can now easily remove the painted dots in the bezel using a toothpick.

IMPORTANT: Do not dispose the Hcl into your toilet or a sink, as results to the piping are unpredictable.

Now rinse, rinse again, and then rinse. Make sure you get that acid out of the watchcase unless you want random funky effects on the dial and/or the movement and/or your skin.

To add an instant aged look, follow the "egg treatment process" as described here and on some other various locations on this forum.

Now rinse thoroughly again. I image it can be awkward to explain the remainders of eggs in the movement to your watchmaker.

Carefully assemble your watch, and admire the astonishing result: Your watch has just aged 50 years in one afternoon.

Hope that was helpful for some of you, I am very interested in your comments / improvements.

 

[schnurrp]

Thanks for that christian! I've done that before but it took 24 hrs. to work probably had to do with both the thickness of the chrome plating and the concentration of the HCL. Chrome can also be removed by reverse electroplating. Google "Caswell reverse electroplating" for lots of info. Caswell is the premier do-it-yourself plating company.

 

[sq100]

Nice writeup! :-!

 

[jose-CostaRica]

sweeeet! it's nice to see the plexy does not need to be taken out.

 

[WelshWatchNut]

Each to their own of course but the finished product looked like it was dredged from a river....not for me as I like the shiny finish. Enjoyed the informative write up though!

 

[Chascomm]

I agree. Perhaps it's just the photo but the post-egg watch just looks to me like it needs a thorough cleaning. I'd rather let nature take its course on an unplated Vostok.

 

[saturnine]

So I gave my new Komandirskie a bath in muriatic acid and am a bit perplexed by the results.

Before:

After over 24 hours total in acid:

The result is that the case, moreso than the bezel, looks to still have a metallic paint applied to it. The overall shine is gone, but now it's sparkly... I already ruined the crown stem in keeping it in acid for too long and I don't think it's going to have any further affect on the case as it hasn't changed it's appearance in the last 8 hours in the acid. Has anyone had the same/different results?

 

[Rimmed762]

I tested different types of cleaners while cleaning my shot brass (rifle cases) and two things came to mind.

Leaving brass into hot water where there are those dishwasher tablets gave brass a very greenish tint.

Vinegar made brass turn reddish.

Or vice versa. Just if easy homemade colouring is wanted.

 

[Matt_Bored_O]

.......Vinegar made brass turn reddish.....

This makes sense.

Acid leaches out the zinc in brass, which turns red.

I'm a horn player (cornet) and it is amazing how fast a brass musical instrument can begin to develop 'red rot'.
The acids in human sweat and especially saliva attacks the brass and causes small pockets of zinc to leach out and
create small red spots.

Brass instruments are coated with lacquer to protect the brass.

 

[Matt_Bored_O]

So I gave my new Komandirskie a bath in muriatic acid and am a bit perplexed by the results.

I assume it was originally TiN coated.

I guess this requires a different method to remove?

 

[Matt_Bored_O]

.
Add baking soda (sodium bicarbonate) to neutralise the acid before disposal.

But I'm not sure it is safe to pour into a drain or in the toilet since the solution contains
a form of chromium.


I buy HCl / Muriatic Acid in the Plumbing section of the hardware store.
The best one is the type that professional plumbers buy. It is usually a higher concentration.
Plumbing supply shops which serve the plumbing industry should have it.

 

[schnurrp]

I assume it was originally TiN coated.

I guess this requires a different method to remove?

Google does not list HCl as a means to remove Titanium Nitride coating. Nitric acid is suggested but nitric will eat brass in high enough concentrations so you would have to do some experimenting.

 

[saturnine]

So I gave my new Komandirskie a bath in muriatic acid and am a bit perplexed by the results.

I assume it was originally TiN coated.

I guess this requires a different method to remove?

As in I should have bought a silver case as opposed to gold? Dammit.

 

[Matt_Bored_O]

As in I should have bought a silver case as opposed to gold? Dammit.

You can use a buffing or polishing wheel with mild abrasive.

Keep moving constantly the wheel or the case, to remove the coating uniformly.

 

[Lord Dunsany]

Are we sure this wasn't simply coated with clear lacquer at the factory? I've patinated other brass objects and this is how they look after partination, but before I removed the coating. Try some lacquer thinner.

I assume it was originally TiN coated.

I guess this requires a different method to remove?

 

[Matt_Bored_O]

Are we sure this wasn't simply coated with clear lacquer at the factory?

I was quoting the description used by most sellers.

It is not uncommon for manufacturers and sellers to be 'flexible' in their product descriptions.

Brass musical instruments are always coated with lacquer and not TiN.