Buying gen cases--pitfalls (and pits)?

[Serafino]

I gather there is a fair likelihood that any gen case that is up for sale will be one that is so worn that it made more sense to part the watch out than try to sell it whole?

I have read that some of these cases can be warped? Buying over the internet I guess there's really no way to tell if this is the case with a given example. So it is asking for trouble to order something from someone that has no return policy, since you can't check for warping via a picture?

I also presume that aside from all the usual spots where corrosion can happen and have a cosmetic impact, one has to really be careful of pits or black spots round the outside of the projection which the crystal fits around (haven't managed to dig up that part name yet), and watch for pitting/spots in the threads of the case and back?

Thanks for any help in negotiating this minefield.

[freddy333]

I would say that your suppositions are, for the most part, wrong.

In most cases, cases are sold because the movement was parted out for use in a franken. In these cases, the condition tends to be good. But if the seller fails to post good, clear pics of the entire case, he/she is trying to hide something. As always, buy the seller before you buy the watch.

[automatico]

"In most cases, cases are sold because the movement was parted out for use in a franken."

True.

Some movements are used for parts or replacement in a higher value genuine rolex.

I have purchased quite a few cases in the past 20+ years and they ranged from nos to junk and the biggest problem in vintage cases seems to be case corrosion.

Look between the lugs and on the back side of the case for black pits or specks that will not scratch off with a stiff brush or toothpick...this is a sign of light to heavy corrosion and it can be bad enough to eat all the way through the case but still not appear to be very bad on the outside.

Check the case and caseback where the gasket seals them together and look closely for corrosion and check gasket grooves closely for pits. This can kill a case and the trouble is that it does not show from the outside.

If possible, remove the bezel and crystal and look closely at the top of the case where it was covered by the bezel. There can be some heavy corrosion hiding under a bezel. Look for nicks on the case neck where the crystal or crystal gasket mounts, usually caused by careless bezel removal. A significant nick here can cause a leak that can not be easily fixed.

Lay the case on a level surface and see how much it rocks on the lugs. A little bit is Ok but a lot is not. Had a 16014 that was bent about 4mm on one lug. It was bad enough that the case was bent so much that the caseback seized on the case...junk!

Look for thin lugs from damage repair or careless polishing. Had an acrylic quick set GMT 16750 that looked like it had a peg leg on the 5 o'clock side.

Look for worn or out of round springbar holes in the lugs.

Check damage to cases between the lugs caused by loose fitting hoods. There is not much that can be done about this but if the reference and serial numbers are gone, the case is not worth as much.

Measure between the lugs and make sure the lugs are not bent. I had a genuine 6538 that was 19mm on one end and 20mm on the other. It had lived a hard life.

Make sure the caseback and case threads are good. If possible, wash the case and caseback in hot soapy water, dry it, and see if the caseback screws on and off easily and evenly without gaskets. If it chatters or binds, lube it lightly with silicon etc and try again. If it still chatters or binds, look closely for thread damage or bent case/caseback.

On sporty cases...see if the crown guards are even and pretty close to the right size.

etc, etc...

There is a LOT of junk out there and watch shows, eBay etc are dumping grounds for ratty cases that look good on the outside. Be suspicious at watch shows, trade shows etc if the caseback is screwed down real tight on an empty case so you can not examine it.

I bought a 1603 from a seller in HK and it looked 90% on the outside but was rotted out inside around the gasket area...it is now residing in my trophy case of lost causes. Got a 16220 that was the same way but got a refund. I've seen a whole lot of 16000 type cases that were rotted out. Never saw a rotted out 1550 or 15505 case but I am sure they are out there.

Seen a lot of rotted out submariners, some of them not that old.

Stainless? Maybe.

Corrosion resistant? Sorta.

Rot out proof? No.

[Serafino]

Wow, awesome info. thank you very much. I will digest this and return with any questions.

[Ronin]

I agree with Freddy. Also, I have worked with a case that had pits, and looked worn. Guess what! It still was waterproof and cleaned up just fine. Fear not!