Precision hand polishing/lapping

[dms5150]

Hi there, I have an old Seiko with a case that is precisely faceted with very flat surfaces. Would like to attempt to restore the case, but am weary of rounding off the edges as I polish. Need to hit each face at the exactly correct angle and do it again and again across multiple grits of paper.

Are there any mounts/tripods/clamps that people use to orient a watch at the precise angle they need for flat sanding/lapping? Even with a lapping machine, you'd probably need to mount the watch against something so it faces the machine at the exact angle right?

Looking for some hints and advice from the professionals out there.

 

[Al J]

Well, not many professionals I've ever seen use abrasive paper for case refinishing - they use a proper polishing machine with the correct buffs and compounds. I don't have the benefit of seeing the case you are working on, but if done properly on a bench lathe you can avoid rounding off sharp edges, but like anything in watchmaking this is a skill that has to be learned and practiced to be very good at.

If the case is being lapped, then usually there will be custom jigs and fixtures that would be used to present it at the correct angle. It's specific to the case, so you would have to come up with something for that.

Cheers, Al

 

[DeweyC]

Well, not many professionals I've ever seen use abrasive paper for case refinishing - they use a proper polishing machine with the correct buffs and compounds. I don't have the benefit of seeing the case you are working on, but if done properly on a bench lathe you can avoid rounding off sharp edges, but like anything in watchmaking this is a skill that has to be learned and practiced to be very good at.

If the case is being lapped, then usually there will be custom jigs and fixtures that would be used to present it at the correct angle. It's specific to the case, so you would have to come up with something for that.

Cheers, Al

Aj,

When I took the Coaxial COurse in New Jersey, They showed us the case refinishing dept. Do you remember he had like an 8 inch charged flat faced wheel that against which he handheld the case?

For the OP, maybe you are looking for a dividing head?

 

[Al J]

Aj,

When I took the Coaxial COurse in New Jersey, They showed us the case refinishing dept. Do you remember he had like an 8 inch charged flat faced wheel that against which he handheld the case?

For the OP, maybe you are looking for a dividing head?

You mean this?



This is used for applying the sunburst finish to cases like the old first generation Dynamics (what he's refinishing in the video), Speedmaster Mk. II's, etc.

If you look at Omega's working instruction 93, which covers refinishing techniques, they do use a lapping wheel for flattening out a surface that is already distorted, but the final polishing is done in the traditional manner with a bench lathe.

Cheers, Al