Scratched as new (almost)

[ricardoch]

Hi, I hope you all are fine

Those days I found an old omega f300 cone case sleeping on the drawer polished as a mirror when I bough it, many years ago cheap as scrap.

I decided to give it a try and among other tasks, rescue it's finish, and discovered that it's impossible to do it by hand, each run marks his scratches in a different direction giving even worse impression than mirror polish, so decided to take the challenge of scratching it in a radial and homogeneous pattern.

I read somewhere a post about redoing an Omega cone surface, and found it really difficult, doing supports, regulators and so on, and requiring even a grinding machine, impossible and not to inspiring for me.
Saw even someone using a dremel that took the hell out of me.

Below it's the simple contraption that allowed to do it, maybe you can find it useful for your projects, it's cheap, easy to build and makes the redo a piece of cake.

All the secret is to guarantee that sanding paper (or whatever you use) attacks the surface always in the same "radial" direction, this is impossible if you grab the case or sand paper by hand, any minor deviation will shine as a photo flash ruining the look.

So to do it you may elaborate a complex rotating support, or take a simpler approach.

As the watch is round, almost any "support" that "fills" the case will allow to rotate it around that position keeping the angle and relative position of the case.

So with just a few sticks laying around I've been able to "build" a really simple "fill" to firmly support the case in a fixed position, allowing it to rotate freely but preventing any displacement up down, right or left, so keeping the case in the same relative angle no matter how much you rotate it.

The second challenge was to make a sanding "device"  to scratch the cone wall without any lateral displacement, so, just up and down motion along the cone wall, with any lateral distraction.
Again an old lumber piece and a single carpenter clamp did the trick.

Below are a few photos of the job, cheap, easy and efficient, I hope you find it useful.

It was fun to repair a watch case with lumber, sand paper and carpenter tools, still thinking what use give to the hammer.

My apologies, but don't know how to lay the photos in their  place

Ask if any doubt.
Cheers and take care
Ricardo

[steve1811uk]

That's a really nice finish. What type of abrasive paper did you use? Manufacturer and grade?

[ricardoch]

11 hours ago, steve1811uk said:

That's a really nice finish. What type of abrasive paper did you use? Manufacturer and grade?

Hi Steve, 
Thanks for your comment.
I'm really not sure which brand it's , as per the shape and touch I think it could be 3M wetordry sand paper, possibly 500 grade, used dry, but again not sure, as it was a tiny piece lying around that I used to test, and liking the result decided to go ahead.
Any sanding paper will do as it only lightly scratches the surface with very little pressure. Maybe the only important thing is to use a good quality paper to avoid too much debris.
I think omega's original grind is a little deeper, but as it looked great didn't tested any coarse grade.

I hope it helps
Have a nice new year and take care.
Ricardo