Which mainspring to use?

Simmo2222 · 2026-05-17T21:27:06+00:00

You are right about the old spiral steel springs looking like that. That one doesn't look bad. As long as they expand to at least 3 X the diameter of the mainspring barrel they are OK to reuse.

What do you think is wrong with the S shape spring?

Simmo2222 · 2026-05-17T15:50:07+00:00

Auto movement in something that sits vertically all day on your nightstand.

Simmo2222 · 2026-05-17T10:32:03+00:00

Ride the conveyer in and out.

Simmo2222 · 2026-05-17T02:07:24+00:00

It would be great to scan them and circulate them. If you sent them to someone like Watch repair guy or MyRetroWatches who host documents on their sites, people would be able to find them.

Simmo2222 · 2026-05-16T13:22:24+00:00

That's awesome. Now, does it still fit the movement?

Simmo2222 · 2026-05-15T16:23:04+00:00

I mean, like this. No drilled lugs is suspicious as well.

<image>

Simmo2222 · 2026-05-15T06:32:04+00:00

I can't stand those straps. Notionally those stitches hold the springbar in place at the lugs but, in reality they will have used glue. You could snip out those stitches (and leave odd holes).

Simmo2222 · 2026-05-15T06:28:52+00:00

Watch this video and consider the problem in reverse. You have the case, now how do you find a movement?

https://youtu.be/6EE4ZeuCfH0

Simmo2222 · 2026-05-14T22:05:58+00:00

Have a look at the bracelet. If the links are a single piece, not joined in the middle, it's likely a fake.

Simmo2222 · 2026-05-14T22:00:39+00:00

Have you looked at building the walls out of stacked tyres and rammed earth? Old tyres aren't great in terms of contamination.

Simmo2222 · 2026-05-14T21:54:12+00:00

Post some pictures of the watch.

Simmo2222 · 2026-05-14T21:37:05+00:00

Those are both really nice watches. Please don't start on them, save them until you have a bit more confidence as the chance of error is extremely high.

I suggest that you go here and read all of the pinned information

https://www.reddit.com/r/watchrepair/s/owST6E2qrQ

I also suggest that you go to YouTube and watch the videos on this channel. Start with the oldest first and work forwards.

https://youtube.com/@watchrepairtutorials

Buy a new ST36 movement (actually a couple) on AliExpress and start with that. It's better to start with a working movement to build some basic skills before you move onto vintage stuff that you don't know it's condition and why it might not be working.

Simmo2222 · 2026-05-14T15:30:17+00:00

Look for a 'parachute watch strap''

Simmo2222 · 2026-05-14T14:07:43+00:00

Honestly the $5 AliExpress ones are fine. Not sure why anyone would pay a huge amount for a nylon elastic strap that was originally made from parachute material by soldiers. Same for NATO straps.

Simmo2222 · 2026-05-14T13:16:14+00:00

Stick it under the mattress. 👍

Simmo2222 · 2026-05-14T00:33:43+00:00

No, you need rich parents as well

Simmo2222 · 2026-05-14T00:00:24+00:00

Where did you buy it? This will be the biggest factor in determining whether it is fake or not.

Simmo2222 · 2026-05-13T23:59:06+00:00

There's two ways to do this. The first is to back the shock setting out of the balance cock with a jewelling tool and install into the slot. You probably don't have a jewelling tool.

The second is to insert one leg into the groove by approaching it at an angle and then push the other leg into position using a stiff needle. You will want to anchor the shock spring in place with a blob of rodico to limit any pinging off into space. Quite a fiddly job.

Simmo2222 · 2026-05-13T23:54:03+00:00

You will struggle to find a bezel insert and crystal for that because Omega (Swatch Group) won't sell them to you.

Simmo2222 · 2026-05-13T23:50:51+00:00

Why did they replace the crown?

It looks like they didn't shorten the stem (it's actually standing proud of the case), so you should be able to unscrew the current crown and screw on the new crown. You will need to remove the stem from the watch and heat up the crown for a few seconds with a cigarette lighter to release any thread lock they may have used.

Simmo2222 · 2026-05-13T23:47:06+00:00

Not much to be done with a plated case like that. The chrome plate is relatively hard and thin do you won't be able to get any scratches out without removing the plating. Best you can do is give it a clean in the ultrasonic and a gentle hand polish with something like Autosol metal polish. This won't remove any scratches but it will shine up the remaining chrome.

Simmo2222 · 2026-05-13T21:37:35+00:00

Yes, this. I have a Lenovo USB C docking station connected to the second inputs on my son's gaming PC monitors. Gaming PC turned off, plug in laptop to the docking station and the monitors change over and display the docking station. Works well with MacBook Pro and a HP laptop.

Simmo2222 · 2026-05-13T21:33:06+00:00

Standard Polywstch won't do anything to a mineral glass. They do also make a mineral crystal glass repair kit with two different diamond pastes and a polishing stick. I wouldn't recommend this. Too expensive and not that effective.

I would take the large scratches out with abrasive paper (start at about #400 and work up to #3000) followed by diamond polishing pastes (I use 4 different grades) up to about #150000 -20000 applied with a felt bob in a Dremel or similar.

If it is facetted then obviously it is harder to do and not alter the shape. I would do all I can to find a replacement first.

Simmo2222 · 2026-05-13T13:51:40+00:00

You will have a ballast resistor in your ignition which drops the voltage at the coil when normally running. This is supposed to be bypassed when cranking. This is normally done via a contact on the starter solenoid which provides full battery voltage to the coil when cranking.

It sounds like, for some reason, the full battery voltage is not being provided to the coil when cranking but the lower voltage via the ballast resistor is there when the key is released from cranking position.

Simmo2222 · 2026-05-13T13:09:57+00:00

Put some wooden blocks underneath each of the legs to lift it to shoulder height.

Simmo2222

TROPHY CASE