Need some crystal replacement advice

[VWatchie]

I just picked up this Mondaine quartz watch on tradera.com for £11. It's a non-runner so I will replace the Ronda movement (£10.95 at Cousins), polish the case, replace the case-back gasket, and replace the mineral crystal.

Now, the problem is finding a suitable crystal. The original crystal is slightly domed (2.4mm thick dome), measures 36.4mm in diameter, and is 1.3mm thick at the edge. The closest I can get on CousinsUK is 36.5mm in diameter, 3.1mm thick dome, and 1.5mm thick at the edge. I think the replacement crystal would look OK, but the problem is finding a suitable glass gasket.

The case diameter for the glass gasket is 36.9mm and the closest glass gasket I can find on CousinsUK is either 36.8x36.0mm or 37.0x36.2mm. I guess one of those glass gaskets could work but as you can see there's no way the 36.5mm domed crystal would fit the inner diameters of those glass gaskets. I guess I will have to give up on a domed crystal, no?

So, the backup plan is to use a (1.5mm) thick flat mineral crystal as the diameters come in increments of 0.1mm. But, what glass gasket would be the better option? The one with an outer diameter of 36.8 (0.1mm too small) or the one with an outer diameter of 37.0mm (0.1mm too large). Again the case diameter for the glass gasket is 36.9mm. I believe I read or heard that the crystal diameter should be 0.1mm wider than the inner diameter of the glass gasket. Is that correct?

I'm sorry for all the numbers. I've tried to make it as clear as I could. So, I'd appreciate your thoughts on this.

BTW, measuring and sourcing crystals and gaskets is extremely time-consuming! 

[oldhippy]

The main thing you need to think about is not only size but clearance to the hands. Have you looked at other suppliers or the internet. 

Edited May 15, 2024 by oldhippy

[VWatchie]

2 hours ago, oldhippy said:

The main thing you need to think about is not only size but clearance to the hands.

In this case, the underside of the crystal is flat so I assume I don't have to worry about clearance to the hands. However, perhaps I'm missing something. If so, please let me know.

I guess no one has the patience to get into the details of my first post so here's a simplified version of my question:

The case diameter for the glass gasket is 36.9mm. However, Cousins doesn't have a glass gasket with that diameter. The closest are 36.8mm and 37.0mm. Would any of those two options work, and if so which one? I have no problem ordering both and testing them, but If someone already knows it is pointless, there's no reason to order.

2 hours ago, oldhippy said:

Have you looked at other suppliers or the internet.

No, I haven't. Is there someone you can recommend? Preferably in Europe. Thanks!

Edited May 15, 2024 by VWatchie

[ColinC]

I visited this place last year just before they closed their counter service - amazing shop (filled from floor to ceiling!) and the guy that was working there was really knowledgeable and helpful!. Their website isn't as good as Cousins but I understand that if you fill out the contact form they have stuff that isn't on the site.

https://gleave.london/mineral-flat-bottom-domed/

[Zendoc]

Hi @VWatchie - I have model of this Mondaine quartz watch in my collection, just a smaller size. I bought it many years ago, new.  I wonder if  the crystal on your watch is original?  My original crystal was entirely flat.  I scratched it at one stage and replaced it.  There is a dealer located in the UK who sells replacement crystals for Mondaine on the big E - I bought mine from him.  If you PM me, I’m happy to forward the listing details - he may keep different sizes for the Mondaine range?.  The replacement he sent to me was a perfect replacement for the original.  

On a side note, the Ronda movement in these is very easy and fun to work on.  They’re also very cheap to replace.  I learnt a lot about the big date complication when the smaller date wheel spring mechanism malfunctioned and the date changing stopped. I stripped down the movement and it went back together very smoothly and continues to work perfectly.  I like the streamlined aesthetic of the Mondiane line.  I also have one of their big date mechanical movements which runs on an SW200-1. The crystal on that is also perfectly flat, btw.  

Cheers,

John

[mikepilk]

13 hours ago, ColinC said:

I visited this place last year just before they closed their counter service - amazing shop (filled from floor to ceiling!) and the guy that was working there was really knowledgeable and helpful!. Their website isn't as good as Cousins but I understand that if you fill out the contact form they have stuff that isn't on the site.

https://gleave.london/mineral-flat-bottom-domed/

I have recently started ordering from Gleave. As you say, their website isn't great. I find it best to put the item I'm looking for in the search box, rather than going through the menus. They have a lot more stuff than it seems from the website. They had some Omega parts I needed which Cousins didn't have.

[Neverenoughwatches]

On 5/15/2024 at 1:49 PM, VWatchie said:

I just picked up this Mondaine quartz watch on tradera.com for £11. It's a non-runner so I will replace the Ronda movement (£10.95 at Cousins), polish the case, replace the case-back gasket, and replace the mineral crystal.

Now, the problem is finding a suitable crystal. The original crystal is slightly domed (2.4mm thick dome), measures 36.4mm in diameter, and is 1.3mm thick at the edge. The closest I can get on CousinsUK is 36.5mm in diameter, 3.1mm thick dome, and 1.5mm thick at the edge. I think the replacement crystal would look OK, but the problem is finding a suitable glass gasket.

The case diameter for the glass gasket is 36.9mm and the closest glass gasket I can find on CousinsUK is either 36.8x36.0mm or 37.0x36.2mm. I guess one of those glass gaskets could work but as you can see there's no way the 36.5mm domed crystal would fit the inner diameters of those glass gaskets. I guess I will have to give up on a domed crystal, no?

So, the backup plan is to use a (1.5mm) thick flat mineral crystal as the diameters come in increments of 0.1mm. But, what glass gasket would be the better option? The one with an outer diameter of 36.8 (0.1mm too small) or the one with an outer diameter of 37.0mm (0.1mm too large). Again the case diameter for the glass gasket is 36.9mm. I believe I read or heard that the crystal diameter should be 0.1mm wider than the inner diameter of the glass gasket. Is that correct?

I'm sorry for all the numbers. I've tried to make it as clear as I could. So, I'd appreciate your thoughts on this.

BTW, measuring and sourcing crystals and gaskets is extremely time-consuming! 

Is the crystal gasket a hard gasket ?

20 hours ago, VWatchie said:

In this case, the underside of the crystal is flat so I assume I don't have to worry about clearance to the hands. However, perhaps I'm missing something. If so, please let me know.

I guess no one has the patience to get into the details of my first post so here's a simplified version of my question:

The case diameter for the glass gasket is 36.9mm. However, Cousins doesn't have a glass gasket with that diameter. The closest are 36.8mm and 37.0mm. Would any of those two options work, and if so which one? I have no problem ordering both and testing them, but If someone already knows it is pointless, there's no reason to order.

No, I haven't. Is there someone you can recommend? Preferably in Europe. Thanks!

The overall size you are aiming for H is 36.9, so whatever combo size of glass and gasket  closest to this, one above and one below. What type of gasket is involved ?

[VWatchie]

12 hours ago, Neverenoughwatches said:

Is the crystal gasket a hard gasket ?

I don't know how to describe it. Maybe as semi-hard. If you've ever ordered one from Cousins you'll know what they're like. I have the original gasket intact but I want "fresh" parts. Worst case scenario I'll reuse the existing gasket with a flat crystal having the exact diameter.

My concern is I can't find a gasket with the exact outer diameter. It's either 0.1mm too small or too large. Anyway, I got a tip from @Zendoc of an eBay seller who's good with Mondaine so I'll get in touch with that seller and see what he can do.

[Neverenoughwatches]

21 minutes ago, VWatchie said:

I don't know how to describe it. Maybe as semi-hard. If you've ever ordered one from Cousins you'll know what they're like. I have the original gasket intact but I want "fresh" parts. Worst case scenario I'll reuse the existing gasket with a flat crystal having the exact diameter.

My concern is I can't find a gasket with the exact outer diameter. It's either 0.1mm too small or too large. Anyway, I got a tip from @Zendoc of an eBay seller who's good with Mondaine so I'll get in touch with that seller and see what he can do.

I was thinking will the gasket stretch at all to match the desired size. 

2 minutes ago, Neverenoughwatches said:

I was thinking will the gasket stretch at all to match the desired size. 

Did i also deduce that the original gasket is thinner (0 .5mm ) than the cousins gasket ( 0.8mm )  could that just be an effect of you measuring the case for the gasket size  H  ?