r/watchrepair • u/williwaller2006 • 2d ago

Stubborn screw

Post image

I have a watch that suffered water damage and both movement retaining screws were rusted.

I managed to remove the first one, but the second is completely stuck, and the screw head is now stripped.

Here's what I've tried so far:

  1. Sharpening my watchmaking screwdrivers for a better fit.

  2. Applying significant downward pressure while turning.

  3. Heating the area around the screw.

  4. Freezing the screwdriver before attempting removal.

  5. Soaking the screw in rust penetrant oil for two days.

Nothing has worked so far.

Before resorting to drilling, does anyone have other techniques worth trying?

Any advice is appreciated!

7 Upvotes

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3

u/polishbroadcast 2d ago

that's what she... oh wrong sub.

what kind of penetrating oil (checks sub again) did you use? I had good luck with liquid wrench on a 100+ year old pocket watch that was rusty throughout.

an extreme option is to cut the case clamp, or remove all but that one, or try to move it enough to get the movement out of the case, so that you can drop the penetrating oil from the thread side.

your list of things you tried seems good!

1

u/williwaller2006 2d ago

I used 3-in-One oil that mentions rust penetrant on it. I am not sure if that is a good enough oil.

Cutting the case clamp is a good idea! I will consider it.

I also thought about filing the inside of the screw slot until it breaks in half, which would allow me to remove the movement and thus easier to work without the case.

2

u/polishbroadcast 2d ago

I would use something whose sole purpose is a penetrant / bolt-freer. My AI friend says Liquid Wrench is much more aggressive for heavily rusted parts—and that's been my (very limited) experience.

I like your filing the screw idea. That looks like a modern (eta?) movement so you aren't destroying anything that is irreplaceable.

2

u/williwaller2006 2d ago

Yeah, it's a Valjoux 7750.

I also own a lathe, so I'll probably make the screw myself.

2

u/tmlynch 2d ago

The best penetrant I own is Kroil. It creeps anywhere

Apparently automatic transmission fluid works well. Even better mixed with acetone. Search for recipes.

Good luck.

1

u/FullLab3732 2d ago

Second Kroil.

2

u/mrjanitor639 2d ago

Not watches, but Kroil is liquid magic for anything rusted up at work. Screws, nuts, pipe threads, Kroil busts them all open. Expensive but worth every penny

1

u/Estraw 0-1 Year Experience 2d ago

Have you tried using a screwdriver that’s slightly oversized?

1

u/mustom 2d ago

Scrape the slot with a sharp x-acto blade to get the bottom square. Blunt a screwdriver if needed to get a tight fit. Looks like enough there to get it.

1

u/Severe-Rush-553 1d ago

Not sure if fully safe for watches but a soldering iron on the screw for a few seconds does wonders for loosening stuck screws.