Need advice and tips for replacing UV laminated glass

[VWatchie]

I would like to receive advice and tips for the replacement of a supposedly UV-glued glass. It concerns a fashion watch (Michael Kors) whose original glass is a slightly domed mineral glass. The watch on the right is different but identical.

When I removed the cracked original glass, I found that it appeared to be glued in place. There was no glass gasket. I guess it was glued on with UV glue? I tried to get an original glass but finally had to give up. The diameter of the original glass is 32.1 millimetres.

The closest replacement glass I could find has a diameter of 32.0 millimetres and there is more gap in the case than I expected. Hopefully you can see how big the gap is if you compare the pictures above.

The next size is 32.5 millimetres and is of course way too big. I have heard that you can reduce the diameter with sandpaper but I think that only applies when the difference is very small and 0.4 millimetres sounds a lot to me, doesn't it?

Just in case, I also ordered some flat glasses that fit perfectly in the case but unfortunately, they don't look good.

I have a couple of questions. Is it advisable to glue the glass even though it is too small?

What should I consider when glueing a glass with UV glue (if you think I should do it)? I have never changed a glued glass before. For this purpose, I have bought UV glue and a UV lamp.

As always, I am very grateful for any comments, advice and tips I can get!

[AndyGSi]

First I've never used UV Glue, just the G&S Hypo Cement.

https://www.cousinsuk.com/product/gs-hypo-cement

What thickness is it as Cousins do most diameters?

https://www.cousinsuk.com/product/080mm-domed-cousins

Edited August 27, 2024 by AndyGSi
Link added

[Neverenoughwatches]

53 minutes ago, VWatchie said:

I would like to receive advice and tips for the replacement of a supposedly UV-glued glass. It concerns a fashion watch (Michael Kors) whose original glass is a slightly domed mineral glass. The watch on the right is different but identical.

When I removed the cracked original glass, I found that it appeared to be glued in place. There was no glass gasket. I guess it was glued on with UV glue? I tried to get an original glass but finally had to give up. The diameter of the original glass is 32.1 millimetres.

The closest replacement glass I could find has a diameter of 32.0 millimetres and there is more gap in the case than I expected. Hopefully you can see how big the gap is if you compare the pictures above.

The next size is 32.5 millimetres and is of course way too big. I have heard that you can reduce the diameter with sandpaper but I think that only applies when the difference is very small and 0.4 millimetres sounds a lot to me, doesn't it?

Just in case, I also ordered some flat glasses that fit perfectly in the case but unfortunately, they don't look good.

I have a couple of questions. Is it advisable to glue the glass even though it is too small?

What should I consider when glueing a glass with UV glue (if you think I should do it)? I have never changed a glued glass before. For this purpose, I have bought UV glue and a UV lamp.

As always, I am very grateful for any comments, advice and tips I can get!

I changed the glass to this exact same watch H , the watch itself was 99p with shafted movement and the glass had a chip on the bevel edge and lots of scratches, i got the chip out but the scratches were a different story. So i ordered 2 plain edge from cousins for less than a couple of quid each, swapped the movement out , that was about 12 quid if i remember.  The glass just pressed in, it was tight , the cousins dimensions were a bit off but i did squeeze it in ok. My missus has been wearing it for 2 months and loves it, but then what does she know about watches , i leave her ignorant to the fact that its really crap . Give me a few hours to get you the details of what i used, doing mum stuff today . Next time i see the missus I'll get you a picture of it , the watch looks fine without the bevel cant remember why i didn't order the bevel edge.

Heres the glass H , its not domed just flat, i ordered a 1.5mm and a 2mm thick , but you do have the correct diameter at 32.1mm buddy. The picture shows the old glass on the right that i tried to restore, it was ok but not good enough for me, it does indeed measure 32.1mm. The glass on the left is the cousins 2mm glass that i didn't use it measures 32.15, but i did manage to squeeze the 1.5mm into the case that also measured 32.15. No glue needed just a tight friction fitted, no gasket , i think it pressed into either the steel edge of the bezel or a plastic lip that was inside the bezel. Make sure you protect that DIAMOND  encrusted bezel, i used the polishing cloth that comes with spectacles and folded it over a couple of times .

[VWatchie]

7 hours ago, AndyGSi said:

What thickness is it as Cousins do most diameters?

1.5 mm which unfortunately are only sold in steps of 0.5 mm

[AndyGSi]

Can you confirm the model number.

[Neverenoughwatches]

1 hour ago, VWatchie said:

1.5 mm which unfortunately are only sold in steps of 0.5 mm

?  Are you sure H ? I did get a 32.1mm flat mineral glass in 1.5 and 2mm, i used the 1.5mm 

The code is on the packet in the photo.

Just the non branded glass H 

[AndyGSi]

@Neverenoughwatches he's referring to the domed crystals.

[HectorLooi]

I have glued in a lot of crystals with UV glues. Even undersized ones.

I have used the Sternkreus UV glue before but I didn't really like it. The uncured glue smells terrible and the glue doesn't set hard. It has a very thick oxygen inhibition layer and is very sticky even after curing. The sticky surface has to be cleaned off with IPA or naptha.

The Sternkreus glue is also very viscous and requires a lot of force to squeeze it out of the syringe.

I now use UV glues from AliExpress. I have 3 types of glues, one is a low viscosity type that doesn't set very hard, the 2nd one is a medium viscosity one that sets a bit harder, then a high viscosity one that sets really hard.

For gluing crystals, I usually use the low and medium viscosity ones. The hard setting one, I've used it to set pallet stones. My sifu uses it for gluing silicon hairsprings too.

[Neverenoughwatches]

6 hours ago, AndyGSi said:

@Neverenoughwatches he's referring to the domed crystals.

I see that Andy, in VWatchie's  photo the watch on right which is different but identical ?   looks the same as my wife's which had a flat glass, if VWatchie can post the caseback number to verify .

[VWatchie]

8 hours ago, Neverenoughwatches said:

The code is on the packet in the photo.

Just the non branded glass H

Yes, I ordered a few flat crystals including the one you refer to. Unfortunately, it just doesn't look right to me. Not sure the owner of the watch would complain but I'd like to get as close to the original as possible. If there's one thing I've learned it is that looks are everything and I wouldn't want to disappoint the owner.

The question is if glueing in the slightly too-small domed crystal would pose some unexpected problem. I've learned to take nothing for granted when working on watches.

6 hours ago, HectorLooi said:

It has a very thick oxygen inhibition layer and is very sticky even after curing. The sticky surface has to be cleaned off with IPA or naptha.

Thanks for sharing your experience! What does "thick oxygen inhibition layer" mean? Not ever having glued in a crystal I try to imagine what would have to be "cleaned off". Can you elaborate?

6 hours ago, HectorLooi said:

The Sternkreus glue is also very viscous and requires a lot of force to squeeze it out of the syringe.

I don't have the time to order some AliExpress UV glue so I'll have to stick with my Sternkreuz glue for now. The syringe sounds like it could create a mess. Perhaps squeeze out some and apply it with an oiler for better control?

[oldhippy]

I think you are going to have to get the nearest fit and make sure it clears the hands and use one of the recommended cements. The only other thing I can come up with if you have a lathe you could turn it down to fit by using the different abrasives that are about today. 

[VWatchie]

8 hours ago, AndyGSi said:

Can you confirm the model number.

Do you mean the model number of the watch? If so it is "MK-5354".

[HectorLooi]

27 minutes ago, VWatchie said:

What does "thick oxygen inhibition layer"

Photoploymerization is inhibited by contact with the oxygen in the air. So, the surface that is exposed to air is unable to be cured and remains sticky. The air inhibition layer is necessary to be able to add new layers of resin over cured resin. 

Some resin formulations have a thinner air inhibition layer than others and the final "glaze" layer is able cure without any oxygen inhibition layer at all. Your better halves who visit nail salons will be able to understand this. 

The excess glue that is squeezed out when you put the crystal in has to be cleaned off as much as possible. I sometimes have to "tack" cure a few spots around the crystal to hold it in place, so that the crystal doesn't move around when wiping off the excess. Cleaning off the excess now makes cleanup a lot easier than after curing it.

Hope this makes sense.

[AndyGSi]

Just had a look at a couple of different Michael Kors watches and they all appear to have I Rings.

They also all appear to have Standard size Flat Bottom Domed Crystals.

Is there any chance the one you're working on could have been replaced before?

[Waggy]

18 hours ago, VWatchie said:

I have heard that you can reduce the diameter with sandpaper

I have used this method, 0.4mm sounds like a lot, but remember this is only 0.2mm on each 'side'. I use regular wet-and-dry around 600 grit on a flat surface, and use a rolling action with my wrist, then change 90 degrees, then a few more , then change 90.... and so on. I've had pretty good results. Regular checking of fit id needed as it can get away from you!

I use the G&S Hypo Cement, I did get a tube of Seiko UV stuff, but haven't used it yet

[VWatchie]

2 hours ago, AndyGSi said:

Just had a look at a couple of different Michael Kors watches and they all appear to have I Rings.

I looked around a bit too and it seems that MK uses different technologies. They probably contract different factories in China.

2 hours ago, AndyGSi said:

Is there any chance the one you're working on could have been replaced before?

I don't think so. The owner is the buyer of the watch and she hasn't had it for long.

5 hours ago, Neverenoughwatches said:

looks the same as my wife's which had a flat glass

It can appear flat but is slightly domed. The dome on my replacement is more pronounced but still looks better than the completely flat alternative.

[Neverenoughwatches]

1 hour ago, VWatchie said:

It can appear flat but is slightly domed. The dome on my replacement is more pronounced but still looks better than the completely flat alternative

I'll check the case ref. With my wife's , i still have the glass and its completely flat both sides the case and dial look exactly the same where the bracelet attaches may be slightly different.

[VWatchie]

Now I have glued the domed glass with my Sternkreuz UV glue. I used a green oiler and gradually applied the glue to the joint between the bezel and the surface that the glass is attached to. I was quite generous with the glue, but I couldn't see that it had run out on the inside of the watch after I applied the glass.

Next, I put the watch in my UV lamp and let it shine for two minutes. Then I waited for three minutes and then switched on the UV lamp for another two minutes. The latter was probably unnecessary but it was a whim I had in the hope of making the glue harden even more (maybe it has the opposite effect!?)

Finally, I pressed the glass from the inside to make sure it was not loose. I didn't press hard or loose, but I got the feeling that the glass was well seated.

I think I have solved the problem but I have promised the owner a guarantee if the glass should come off. Probably I am worrying unnecessarily.

8 hours ago, Neverenoughwatches said:

I'll check the case ref. With my wife's , i still have the glass and its completely flat both sides the case and dial look exactly the same where the bracelet attaches may be slightly different.

Perhaps it could be that the factory glues on the glass they currently have in stock? It's not exactly Rolex or Omega. On second thought, my idea is probably not correct but it was a thought.

[Neverenoughwatches]

54 minutes ago, VWatchie said:

Now I have glued the domed glass with my Sternkreuz UV glue. I used a green oiler and gradually applied the glue to the joint between the bezel and the surface that the glass is attached to. I was quite generous with the glue, but I couldn't see that it had run out on the inside of the watch after I applied the glass.

Next, I put the watch in my UV lamp and let it shine for two minutes. Then I waited for three minutes and then switched on the UV lamp for another two minutes. The latter was probably unnecessary but it was a whim I had in the hope of making the glue harden even more (maybe it has the opposite effect!?)

Finally, I pressed the glass from the inside to make sure it was not loose. I didn't press hard or loose, but I got the feeling that the glass was well seated.

I think I have solved the problem but I have promised the owner a guarantee if the glass should come off. Probably I am worrying unnecessarily.

Perhaps it could be that the factory glues on the glass they currently have in stock? It's not exactly Rolex or Omega. On second thought, my idea is probably not correct but it was a thought.

The wifes wasn't glued in , it pressed straight out. No glue around the edge of the original. Next time i see her I'll check the ref. numbers, I'm curious as to why yours was domed. 

[AndyGSi]

I've seen a few of the MK5354 for sale and they do all appear to have a slight dome.

There also appears to be 2 different version where the number is either around the edge or in the centre.

I'm interested myself so I've got one coming from a friend to have a look at.

[VWatchie]

11 hours ago, AndyGSi said:

I've seen a few of the MK5354 for sale and they do all appear to have a slight dome.

Yes, that's exactly how I would describe the glass, "slight dome". 

[Jon]

On 8/28/2024 at 7:44 AM, VWatchie said:

I don't have the time to order some AliExpress UV glue so I'll have to stick with my Sternkreuz glue for now. The syringe sounds like it could create a mess. Perhaps squeeze out some and apply it with an oiler for better control?

That's exactly how I use it. The syringe tip doesn't give you the control and will end up a mess. I always find that the Sternkreuz sets really hard. 

[AndyGSi]

Well it arrived, and in person there's less of a dome than I expected, not sure how well the photo will show it.

 

[VWatchie]

On 9/2/2024 at 4:18 PM, AndyGSi said:

Well it arrived, and in person there's less of a dome than I expected, not sure how well the photo will show it.

Excellent illustration! Exactly what I saw!

[CYCLOPS]

could have been a magnified crystal.....UV glue in or use with gasket, they come in different sizes and thicknesses