Advice on putting brushed finish on side flanks with crown guards

502 to right · Jan 19, 2025

For watches with brushed side flanks I use a bench top polishing lathe with a 4 inch Bergeon 6723-240-LP wheel to get a nice brushed finish. However, the wheel is too large to finish case flanks if there are crown guards (like the Seamaster Professional 300m).

Does anyone have tips for the proper tool or wheel to finish that area of the case? Does anyone know how an OSC does it?

Thanks.

502 to right · Jan 19, 2025

And I'll add this: I know I could use a scotch-brite type pad by hand, but there's no way that's what Omega uses.

vibe · Jan 20, 2025

These come in a couple of different grits work really well:
http://www.julesborel.com/products/...h-buffs/bergeon-5444-a-polishing-product-fine

502 to right · Jan 20, 2025

vibe
These come in a couple of different grits work really well:
http://www.julesborel.com/products/...h-buffs/bergeon-5444-a-polishing-product-fine

Actually I have a couple of those. Have you used it for this application before? Ideally I'd like to find something that's not free handed. Although I just need to get a satin finish applied. Any scratches will already have been removed. I'll certainly consider it.

vibe · Jan 20, 2025

I’ve used them for the tops of lugs and bracelets. To me it is much safer than machine polishing.

Deafboy · Jan 20, 2025

Two good products for finishing cases:
Flat Emery Sanding sticks
GarryFlex abrasive cleaning blocks

The latter is a soft and conformal abrasive.

I recently refinished the lugs on this Seamaster using the sticks. They come in 8 grit sizes. I was able to easily match the original finish of the side of the watch case.

J!m · Jan 20, 2025

I never use power for "brushing" cases.

I use silicon carbide paper on a block that is held square to the surface and move the case against it in smooth deliberate strokes. Usually just a few are needed to get the proper finish.

it is very easy to create "waves" in the metal if you use power due to inconsistent pressure and/or heat buildup. I only use power for polishing.

502 to right · Jan 20, 2025

J!m
I never use power for "brushing" cases.

I'm not talking about a dremel. See 1:19 in the video below. But you can't use this wheel for the parts I'm asking about (see photo at the bottom).

OMEGA Seamaster 300M James Bond 2531.80..webp

Archer · Jan 20, 2025

502 to right
I'm not talking about a dremel. See 1:19 in the video below. But you can't use this wheel for the parts I'm asking about (see photo at the bottom).

That finish is applied using a belt sander sort of arrangement. The presentation of the case to the belt looks like this…

As you can see for the crown side you use the rounded end of the belt. If you don’t have a machine like this, you need to recreate this same sort of method with alternate ways.

502 to right · Jan 20, 2025

Archer
That finish is applied using a belt sander sort of arrangement. The presentation of the case to the belt looks like this…

As you can see for the crown side you use the rounded end of the belt. If you don’t have a machine like this, you need to recreate this same sort of method with alternate ways.

Excellent. Exactly what I was looking for. Could you let me know what grit is used to replicate the Omega brushed finish? Or what grit is a close approximation? I'm guessing 240 or 320.

On slightly different note, I'm obsessed with watching YouTube videos by Vintwatches. I find quality refinishing videos more interesting than videos that strip down and rebuild movements.

J!m · Jan 21, 2025

That's what I do, but manually. If I need a curve, I create it with a buck of some sort, but I never use power personally. It may take me longer, but I get the same result with the absolute minimum of material removal.

502 to right · Jan 21, 2025

J!m
That's what I do, but manually. If I need a curve, I create it with a buck of some sort, but I never use power personally. It may take me longer, but I get the same result with the absolute minimum of material removal.

Now that I'm thinking more about it, I think I could clamp the case in place and use a dowel with sandpaper adhered to it with 2-sided tape perpendicular to the case flank.

The bonus is that I already have all the materials necessary. I have a spare case to work on and will try this.

J!m · Jan 21, 2025

Well, maybe drill a perpendicular hole to mount the dowel into the base and then bring the case to it. Use the largest radius you can.

The critical thing is to keep the strokes absolutely straight and the paper absolutely perpendicular. Handling a dowel by hand you will not hold perpendicularity. And probably have the strokes going off at an angle if you do.

Change either perpendicularity or stroke angle and you will alter the case shape before you know it (best case it'll look weird). That's why I do it slow n steady by hand. Check often. Use sharpie on the surface to indicate where you are removing material. It doesn't take much effort to remove material.

502 to right · Jan 21, 2025

J!m
If I need a curve, I create it with a buck of some sort, but I never use power personally.

Can you explain this? Thanks.

J!m · Jan 21, 2025

Like your dowel- I like PVC pipe a lot, cheap and many diameters available. Otherwise, I'll turn a round into what I need.

I've made a few movement holders and an aluminum Rolex crystal retainer in aluminum because the plastic ones are not deep enough to clear the vintage top hat with cyclops...

502 to right · Jan 21, 2025

J!m
Like your dowel- I like PVC pipe a lot, cheap and many diameters available. Otherwise, I'll turn a round into what I need.

I've made a few movement holders and an aluminum Rolex crystal retainer in aluminum because the plastic ones are not deep enough to clear the vintage top hat with cyclops...

So use a cylinder of some type, held vertical and stationary, and move the watch case across it? If yes, that shouldn't be hard to configure.

J!m · Jan 21, 2025

Correct.

Or, a solid block, for straight sections or convex radii.

noless · Jan 21, 2025

i usually wrap the sandpaper i am using around a suitable stick till i get the radius i want and then clamp the lot into the lathe and put the brushing on like that. this way the sandpaper is not going to move and there are lots of points of reference around the lathe to let me know that i am going to be perpendicular to the part appropriately.

for what its worth i have found that the cloth backed sandpaper works better than the paper backed sandpaper for this purpose, where that small amount of softness helps get the grain into the gaps without having to push really hard.

at the end of the day though, try out a few techniques and see what works for you. what matters is the result not so much how you got there.

Archer · Jan 21, 2025

J!m
The critical thing is to keep the strokes absolutely straight and the paper absolutely perpendicular. Handling a dowel by hand you will not hold perpendicularity. And probably have the strokes going off at an angle if you do.

Actually it’s not difficult at all to keep the grain going in the right direction when moving the dowel by hand with a little practice. But rather than a dowel, I use a piece of round brass stock. The weight gives it some additional stability that helps keep the grain going the right way.

502 to right · Jan 22, 2025

Thanks for the guidance!