Dirt or corrosion on Seamaster caseback embossing?

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iosist

·Jul 23, 2025

I'm looking at this eBay 166.010 - not as nice as some of the others been looking at, but perhaps that will be reflected in the final price. The only thing that really sticks out is this brown residue on the caseback. I would normally assume that it's normal for old watches, but if it could have been easily cleaned in an ultrasonic machine (the seller specializes in parts and watchmaking tools), why wouldn't they have done it before taking photos? The rest of the watch looks pretty clean but I've included all the pics below. Thanks again!

 

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Dan S

·Jul 23, 2025

Looks fine to me.

 

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iosist

·Jul 23, 2025

Dan S

Looks fine to me.

Do you think a watchmaker could get it cleaned up nicely in a service? It's not at the top of my priorities but a crisp hippocampus engraving would be a nice thing to look at.

 

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Davidt

·Jul 23, 2025

Almost certainly just dirt and grime.

 

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SOG53

·Jul 23, 2025

Seller laziness

 

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watchyouwant

·Jul 23, 2025

Find out. Take a toothpick and try to remove it ...

 

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darkguyver

·Jul 23, 2025

Davidt

Almost certainly just dirt and grime.

I agree. Some warm soapy water and a toothbrush should clean that up nicely.

 

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DON

·Jul 23, 2025

Wrist cheese. Used to clean it off with stim-u-dent sticks

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darkguyver

·Jul 23, 2025

DON

Wrist cheese. Used to clean it off with stim-u-dent sticks

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Wrist cheese 😂🤣😂🤣

 

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Dan S

·Jul 23, 2025

SOG53

Seller laziness

Dirty watches often sell for a premium.

 

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impalla62ss

·Jul 24, 2025

Hydrosonic bath should do the trick

 

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darkguyver

·Jul 24, 2025

impalla62ss

Hydrosonic bath should do the trick

Just take the back panel off the watch and place it in the hydrosonic bath rather than put the whole watch in it. Otherwise you may damage the watch

Edited: Jul 25, 2025

 

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impalla62ss

·Jul 26, 2025

darkguyver

Just take the back panel off the watch and place it in the hydrosonic bath rather than put the whole watch in it. Otherwise you may damage the watch

Watchmakers typically remove the movent first, but your suggestion of just doing the case back would be a cheaper option.

 

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bazelot

·Jul 26, 2025

it's just dirt.

 

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darkguyver

·Jul 26, 2025

impalla62ss

Watchmakers typically remove the movent first, but your suggestion of just doing the case back would be a cheaper option.

Yeah, I know that watchmakers take apart everything including the movement to clean them in hydrosonic baths. After they have been cleaned they put the watch back together again, and oil it.

 

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hant26

·Jul 27, 2025

They have a huge selection of watches, so they probably don’t bother cleaning the case or bracelet of a specific watch. This one is really nice, but the second hand might need to be replaced.

 

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AG77

·Jul 27, 2025

Good call on the second hand. Definitely too short, not right.

 

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iosist

·Jul 27, 2025

hant26

They have a huge selection of watches, so they probably don’t bother cleaning the case or bracelet of a specific watch. This one is really nice, but the second hand might need to be replaced.

Oh wow thanks for pointing that out! I definitely wouldn't have noticed the incorrect second hand. Seems like genuine ones can be found pretty readily and cheaply at least! I wonder though if one part being aftermarket might indicate other problems with the watch?

Edit: Upon further investigation, OEM second hands do not seem to be readily available whatsoever 😅

Edited: Jul 27, 2025