How to Properly Attach a Watch Bezel?

[TimeWerks]

I have been working on a Maurice Lacrois watch with an 18k gold plated bezel and I don't want to mess it up.  Here is a picture with bezel placed on the case without the gasket inserted.

 

The bezel was off before I received the watch, and it was really obvious someone else was in the watch before me so I am not entirely sure how it would have been attached from the factory.  Based on the messed up gasket that came with it (seen above),  my guess is that is needs to be a red gasket (0.5 mm thick x 0.9mm tall).

One side of the gasket has a bevelled edge, and I am pointing that outward from the bezel towards the case.  I have tried pressing it dry and also with a bit of silicon grease.  The gasket selected is the only size that fits snugly on the bezel diameter.

I tried pressing the bezel in, but it does not want to compress the gasket in all the way round.  Not sure if I am using the wrong size or type of gasket, or not setting up the press properly, or need a stronger press.  I have tried a chinese screw down press and a heavier duty green lever press.   I have selected concave plastic dies for the top and bottom.  Picking dies slightly wider than crystal diameter of both bezel and clear case back.

Sorry for the horrible press picture.  You can't really see it, but part of the gasket is not fully pressed in on a third of the circumference of the watch every time I try pressing it down.  I have tried flat dies for the bottom and also concave dies.  The bezel never is secured to the case.

I tried using the old green lever press as well with similar results.  What press is recommended?

Should I be using metal dies with protective plastic sheets instead of plastic dies so there is less give?

Do I need to use a different type or thickness of gasket?

 

[ColdWind]

If my memory serves me right, the last time I worked on a Maurice Lacroix I fit the red gasket to the case first then press in the bezel. It really does not require lot of force cause I was able to press down the bezel by hands. I only use a pressing tool afterward to make sure the bezel sit all the way down. For red or white plastic gaskets, sometimes you put the gasket in the bezel/case back first then press, sometimes you have to put it in the case first. If it doesn't work try the other way around.

[TimeWerks]

Thank you for your response ColdWind.   I did try inserting the red gasket into the case initially, and was not successful in my first attempt at that.   I will try that again since it really does not seem to want to go in attached to the bezel itself.

[RichardHarris123]

I don't know but I  would definitely grease it and are you sure the stepped bit faces the way you have it?

[watchweasol]

Hi are we totally sure it’s a round gasket and not a flat one. Perhaps it won’t fit as it is unable to compress the gasket you have, I would try a red flat gasket and see how it goes 

[RichardHarris123]

I think it's the correct gasket, just not sure which way round it goes.

I think the step goes into the bezel. 

[TimeWerks]

I did apply some silicon grease to the gasket but it still did not allow the bezel to push all the way in.  I could try it the other way round so that it steps into the bezel instead.  I think I already tried that by accident before I realized there was a bevel (step) on one side.  I will be away for a couple of days so unfortunately can't experiment at the moment.

I am not sure what type of flat gasket would work.  Assuming it is not an i-ring (which I believe are strictly used for crystals), not sure what flat style gasket would work.  All the red gaskets I have seen are the same main dimensions of around 0.55 mm thick by 0.9 mm tall.  If I could find a thinner gasket I would try that.  I have not found the white gaskets mentioned earlier.

[Kalanag]

On 12/12/2023 at 2:55 AM, TimeWerks said:

…The gasket selected is the only size that fits snugly on the bezel diameter...

I assume that the volume of the gasket doesn‘t fit the volume of the annular gap. The rubberlike Arnitel material (thermoplastic elastomer) can be deformed easily but is not compressible. Therefore I would try gaskets with smaller diameter in order to reduce the thickness by stretching.

Edited December 13, 2023 by Kalanag

[TimeWerks]

Thank you once again for the suggestions, the problem was resolved.  Found a white gasket that was half the thickness of the red gasket (0.45 instead of 0.9 mm), and I was able to successfully attach the bezel to the case.  Placed the gasket on the bezel, with the chamfered side facing out.  With the right gasket it went in much easier.

Lessons I learned so far about Gaskets.

Lubricate or not?  If the part needs to be twisted on, use a gasket with fomblim or silicon grease on it.  If it is pressed straight in place, do not grease the gasket.  The grease itself is not a sealant, it's a lubricant, and meant to avoid damaging the gasket when it is being maneuvered into position.  O-rings are the most common type of gasket you would grease with a very thin layer.

Gasket will often have a proper side up.  Check carefully for a chamfered edge on a red or white gasket that should be on the leading edge going into the piece.  An L-ring gasket would fit with the L sitting down in the inside ledge of the case or bezel (the crystal will press against both the side and the bottom to get a good water seal).

What size gasket?  Measure the outside of both of the shoulders on the case and bezel to see what the difference is and order the appropriate width. Try 0.1 mm larger as a starting point.  Measure the depth of the shoulder to determine the height of the gasket.  Try to be flush with the top of the bezel with respect to crystal gaskets.

Gasket just a bit too thick?   Sometimes a very small .001 difference is all it takes to go from failure to success.  You could try picking a gasket one size smaller in diameter and gently stretch it by rolling it between your index fingers.   Alternatively you could try putting it on the case back and placing it in the freezer for an hour for it to shrink a fraction.  Try putting the gasket in the case instead of on the bezel. 

When pressing in gasket, triple check that there is a consistent spacing between the case and the back or bezel all the way round.  The gasket needs to be pressed in evenly to avoid any pinches in the material. Use the old gasket until you are finished all your post checks, then put the final new gasket on.

I had to search several places to find sets of the different types and sizes.  No one supplier has all the styles.  Different subset of styles are available at CousinsuUK, Esslinger, Cas-ker, JulesBorel, OttoFrei, Startime, Timeconnection,  AliExpress and TheORingStore. 

Black-O ring: - common case back gasket.  Need ID (inner diameter) and cross sectional thickness of gap you need to fill.  Watch material shops have sets of thinner gaskets, but I needed to go to theOringStore to find thicker gaskets for an Aquastar I was repairing.  They have different shapes, and different types of gasket material, but no convenient set for a range of watch sizes.   AliExpress is where I found inexpensive sets of O-rings with a range of inner diameters and thicknesses of 0.5, 0.6, 0.7 or 0.8 mm.   You normally grease o-rings.

Red Gaskets  - Guccii, Tissot, Omega watches

These need to be an exact fit and are normally are put in place dry.  "The rubberlike Arnitel material (thermoplastic elastomer) can be deformed easily but is not compressible" - kalanag.  You can find them at regular watch material shops, but most seem to be a similar thickness of 0.9 mm.  Don't reuse these gaskets.

White Gaskets - can be used interchangably where red gaskets normally would be used, but I found them to be available in thinner sizes than red gaskets.  Assorted boxes on AliExpress.  Don't reuse these gaskets.

Green Gaskets - similar to red gaskets but specifically more water resistant?  I have never seen these for sale, but understand Red Gaskets can be used instead.

Silicon Gaskets - very thin O-ring style used for Gucci, Tissot type watches.

Flat Gaskets - like a flattened ring, normally about 0.5 mm thick, need to match ID (inner diameter) and OD (outer diameter) of the gap it is placed in. It will be pressing against the case back.  Found an assorted box of watch diameter sizes at CousinsUK.

Thin Flat Grey Gaskets - older style to protect from dust, but not water resistance so replace with a different newer style.  

Lead gaskets - some vintage watches had these, carefully remove, safely dispose of the lead and replace with an O-ring gasket.

I-Ring Gaskets - shrink-less plastic used for flat mineral or sapphire crystals.  Don't grease these. 

L-Ring Gaskets - shrink-less plastic gasket for thicker crystals often on divers watches.  Don't grease.

Crown Gaskets - very small O-rings used for "waterproof" crowns.  These will go either inside the crown, or fit over the crown tube depending on the watch.