Opening an 80's Hamilton

[untakenname]

I've been trying to open this watch tonight but there's no indent on the back to get a knife/screwdriver under.



I've tried twisting the front as it looks like it could possibly unscrew but haven't applied a lot of force as don't want to damage it, I've been on youtube and seen 'crystal pullers' but these seem to be for vintage watches and this isn't that old.


Anyone have any ideas?

[Barchettaman]

Possibly a silly question but have you checked round the caseback with a loupe?

Sometimes the little slot for the caseback tool is tiny.

[bazza.]

In the 2nd photo you can see where the opening lip is

[untakenname]

I'm pretty sure the mark in the second photo is from trying to pry it open with a small blade

Managed to take better photo of the mark with at 10x from a 3rd hand soldering magnifier



I went around the circumference first with a pin to see if there's any hidden depressions but couldn't find any and now it hits the mark made but it didn't before.

[UnclePat]

With a case back that’s of clearly different composition - unplated stainless steel - to the middle case, I’d be very surprised if that were anything other than a snap-on case back.

I very much doubt it needs a crystal puller to take out the movement via the front, as that is typically only necessary for mono-bloc case types.

The scalloped bezel around the crystal is almost certainly decorative-only, so it’s a waste of time twisting it.

It’s hard to tell because the photos aren’t particularly sharp, and it could just be the angle, but in the latest photo it looks almost like there’s a long, asymmetric edge to the case back, on the lower side opposite the crown. If so, I’d start there. EDIT: On second glance on a bigger screen that just looks more likely to be visual distortion caused by the magnifying lens, rather than an actual protruding lip.

If not, then as others have suggested you really need to get a closer look for a lip or hollowed edge indicating where to pry it off – typically between the lugs.

As a last resort, then a sharp, broad knife blade – a Swiss Army Knife works well – could be slid anywhere between the middle case & case back (but don’t do it against the crown, or you’re liable to snap it off) and gently levered off. Use the length of the knife edge as a lever and rotate the whole length of the blade to pry it upwards (i.e. don’t use the tip of the blade, hold the handle and twist it like you would a key in a lock).

Some electrical tape would help avoid undue scratches to the case, and a sturdy, folded protective tea-towel in hand in case the knife slips towards you.

If it’s really snug as a snap-on case back, then you may have trouble getting it back on afterwards without a case-back/crystal press, but I’ve used a hard-back book or similar in pinch, with a really firm & evenly spread downwards pressure. Just be careful what surface the crystal rests on whilst doing it, or you could crack it in the process.

Before poking around inside, I’d probably get a cleaner environment to work in & brush away any dead skin & crud before fully removing the back.

Make sure you don’t slip and damage the copper coil too when replacing the battery, or you’ll be in bother.

Good luck.

Edited by UnclePat on Wednesday 30th October 14:16

[untakenname]

Thanks very much for the advice, I took the strap off and wedged a thin knife on the straight part of the case between the lugs and with a little bit of persuasion the back popped off.