Hi All

Nearing the end of my Ploprof overhaul/resto. I’ll be sure to post pics once complete.

I have questions about the step ring that sits between the dial and crystal. It has suffered some corrosion from the melted gaskets and looks a little ratty. See pic. So I picked up a replacement but it’s a little different. It has a groove on top and a black (pvd?) coating. The original is flat on top and dark brown (anodized?).

Was it changed during production run or is the new one a service replacement?

Does anyone know what the coating was on the original? Was it anodized? Or painted? Or something else?

Everything appears original to the watch so the goal is to keep it ‘correct’.

Appreciate the input.

Cheers

 

Hi,
on my 1972 ploprof the step ring was two pice part, lower was I think black plastic and the upper part was made of black anodized brass.
The service replacement part is pvd coated one piece.

 

What is the thin ring laying on top of the screw ring on the left? Is that the compressed crystal gasket?

Is the lower part of the step ring you describe as plastic the same as the ‘rubber segment’ in the exploded schematic? See pic below. Mine was a melted mess so I can only assume it was rubber. Furthermore the seal kit I obtained for it has 2 orings of 28mm ID. Which fits perfectly under the step ring. However the other one is too small for the crystal. Is it supposed to be stretched over the step ring and compressed by its beveled edge squeezing it up to the underside of the crystal? Seems like an odd sealing mechanism to me.

 

The part on the right appears to be upside down. Try measuring the outer diameter of the groove and compare to the diameter of the dial.

Where did you get the exploded view from?

Cheers, Chris

 

It’s the right side up. The bottom side is recessed to fit into the case around the dial. Same as my original step ring.

Another member here supplied me with the schematic but it’s on the internet if you search.

 

OK, you've made up your mind so, good luck.

Chris

 

I don’t have a clue if it’s upside down, backwards or inside out. All I do know is that Chris knows what he’s talking about and it might be worth a second look. In fact Chris is currently servicing my ploprof at the moment.

 

Hi Chris

I appreciate you are a long term respected member here but your dismissiveness made me chuckle.

I didn’t ‘make up my mind’ as to the orientation of the ring. The Omega engineers did that for me by ensuring it only fits one way. The top diameter is greater than the bottom diameter and will not locate in the case upside down. The pic below is of the underside of both rings. Difficult to see on the new ring but on the old you can see a deeper recess to accommodate the dial/movement.

And while I appreciate your well wishes I can assure you that I don’t rely on luck with my rebuilds. Only concrete information.

 

Se my response above. It looks, that there were at least 3 versions of the step ring: two-piece brass+plastic, one-piece full brass, and one-piece modern service replacement.

 

Thanks for all that info.

Interesting there are 3 different setups.

Do you know the color of the original coating (presumably anodized)? Mine is dark brown. Or is this a faded black?

Cheers