Jump to content

Fitting a watch crystal


Recommended Posts

Hello again. Following my request for help finding a watch back the only option seems to be fitting a low dome crystal instead so the back becomes see through, curtesy of philipk5

My question is how much bigger than the actual size of the hole should a watch crystal be to ensure a tight fit but still fit in.

The diameter measures 27.8mm and as it's only a cheap watch which I want to fix as usable for my son but I don't want to spend loads of money buying a range of sizes.

Any advice would be appreciated.

Thanks, Mike

Link to comment
Share on other sites

If you still find it loose and you need it to stay put.....on a cheap watch....just a tiny bit of super glue applied to a well cleaned oil free case..three or four tiny spots..so you wouldn't notice it.and the crystal will stay in place .

  • Like 1
Link to comment
Share on other sites

If the internal diameter of the case measures 27.80mm then a 28.00 low dome acrylic should be able to be fitted using a "claw". It needs to be tight enough to provide some sort of seal and not fall out but not so tight it won't fit!!.

If you use any sort of adhesive it will make removing the acrylic somewhat difficult in the future (probably next week when a proper case back turns up). 

Also make sure that the crystal doesn't foul the stem &/or pushers and any moving parts.

Photos of your watch front & rear may remind someone they have something in their scrap bin?

Hope this makes sense, and helps keep another watch in use.

Cheers

Phil.

  • Like 1
Link to comment
Share on other sites

A simple cheap alternative would be to make a case back from a CD (Compact Disc)

I have a habit of stringing up CD's in the garden. After they have weathered the coating comes off and they are clear but not as transparent as a watch crystal. Also the ones I have had are 2 part laminates which easily separate after weathering. I have used these in the past for emergency crystals in cheap watches.

In this case you could use a new CD. Cut out a circle which fits tightly into the case. Cut another circle which fits over and to the overall diameter of the case and glue the 2 together. Alternatively just cut a circle which fits the overall diameter of the case and glue it on but glue it all around so to seal it. Trim if necessary with a file, sandpaper etc.

It should not scuff up as quickly as a crystal. I use scissors to cut after the CD has delaminated ie one half but I use my scroll saw to cut a full thickness CD

Link to comment
Share on other sites

   the use of glue, on the crystal, will reduce the value of any watch!  if you must use it,  use epoxy,  on the bezel, because it can be removed easily  with 200 degrees farenheight.    there are many instructions on proper "crystal replacement".  vin

Link to comment
Share on other sites

If you have the dimensions I can have a crystal custom made to any profile or flat, costs are at most two euros.

I also have abundance of desent european quality vintage NOS flat crystals at low price.

Cutting is done with grinding stones.

To alter one and make fit yourself. Use a razor blade to shave off the circumference down to a perfect fit. 

The art of perfect fit is patience.perfect fit gathers no or minimun dirt. 

The diameter is to be 2/100 of a millimeter larger for tight fit.

If polymer try heating the case , insert the crystal, keep under press, raise tempto get the polymer melt fit. 

A good press insertion dose a lot of good for flat crystals.

Regards joe

Link to comment
Share on other sites



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • Many thanks for your advice (being borne in mind at present) & offer Dell. When I was given the clock the plastic anchor was loose on the arbour (it had split at the 'hole') &, after repairing this, I have been trying to determine whether the spindle (pin) should be perpendicular when the pallet is sitting on a flat surface; or whether, when installed, its L-R extremes (or alternatively its tick & tock points) should lie at equal angles from the vertical when moved with spring absent. I can get the clock to run but in every such configuration the top block has to be turned anti-clockwise (from above) by quite a bit in order to be 'in beat' & it always runs fast (despite the pendulum being set to as slow as possible). This makes me wonder if there is any particular feature of/fault in a torsion spring clock which determines which turn direction (if any) is necessary to get it 'in beat'; & whether there would be a different set of settings that would get it running nearer to time at somewhere around the mid timing/inertia position which would then allow tweaking of the fast/slow setting.
    • Now this has happened I bet China or India just to name two will start to produce none genuine parts.  I did. But idiot Boris Johnson failed miserably in his negotiations. The E U stitched up the UK like a kipper. Nigel Farage  offered his help but big head Boris declined. So this is why we are in this mess all because Johnson wasn't clever enough.  
    • Hands up all those who voted to leave the EU 😂, oopsie.  UK has just signed the Hague convention, next year that will provide cross border clout to British courts.
    • Ive heard about that oil before for the lever pins. I found it easy to work on , it didn't have a whole lot of pivot wear but i bit sloppy on the lever cock, i think you have to live with what you have or bin it. Stiff to wind and set ?  Not a cannon pinion issue that has no friction thats made up further back and if I remember the barrel drives the hour wheel. No problem on this one .Let me know when you start it as i have another that donated to this one, i can work alongside you with it, two heads are better than one. 
×
×
  • Create New...