I need help using a watch crystal press

[easthammer]

I have just got a crystal press and following instructional videos i cannot seem to get the hang of it.  Its a high dome crystal and .02 bigger than the hole and it wont press in. I managed to get it in with the claw type but it leaves marks on the crystal due to the pressure and i dont want any marks. Does anyone have any tips. I have steel and nylon dies. 

 

 

[Melt]

A tiny bit of lubrication will help acrylic and glass crystals slip in. The lubrication I sometimes use is silicone grease but it's a really tiny amount and I only use on the stubborn ones. I guess you can use other slippery substances but don't overdo it.  I once recieved a Seiko diver swimming in silicone grease or Vaseline on the crystal gasket, crystal, chapter ring, dial.......not what I wanted to see!

[VWatchie]

8 minutes ago, Melt said:

A tiny bit of lubrication will help acrylic and glass crystals slip in.

Never saw this and never heard anyone mention it before reading your post. Anyway, it makes sense. I guess  Yes, some crystals are silly stubborn, and I've cracked a few. Next time I'll try with a tiny bit of silicone grease.

55 minutes ago, easthammer said:

Its a high dome crystal and .02 bigger than the hole and it wont press in.

So, 0.02mm or 0.2mm? If it's 0.2mm larger than the hole I believe that would explain why you can't get it in. 0.1 mm larger than the hole I believe is the common practice, and even then that can sometimes be very hard to fit.

[GuyMontag]

The walls on the acrylic die are angled, not straight, correct?

[easthammer]

Just now, GuyMontag said:

The walls on the acrylic die are angled, not straight, correct?

correct but the 0.02mm is proving an issue centring maybe and i cant get it to compress   

22 minutes ago, VWatchie said:

Never saw this and never heard anyone mention it before reading your post. Anyway, it makes sense. I guess  Yes, some crystals are silly stubborn, and I've cracked a few. Next time I'll try with a tiny bit of silicone grease.

So, 0.02mm or 0.2mm? If it's 0.2mm larger than the hole I believe that would explain why you can't get it in. 0.1 mm larger than the hole I believe is the common practice, and even then that can sometimes be very hard to fit.

If i could get 0.01 on the HW acrylic crystals i would but can only get them in 0.02mm increments.

[GuyMontag]

And the lower die is a domed die, not the kind you are showing in the photo?

[easthammer]

42 minutes ago, Melt said:

A tiny bit of lubrication will help acrylic and glass crystals slip in. The lubrication I sometimes use is silicone grease but it's a really tiny amount and I only use on the stubborn ones. I guess you can use other slippery substances but don't overdo it.  I once recieved a Seiko diver swimming in silicone grease or Vaseline on the crystal gasket, crystal, chapter ring, dial.......not what I wanted to see!

Ok will give grease a go next time but i dont think that alone will do it 

Just now, GuyMontag said:

And the lower die is a domed die, not the kind you are showing in the photo?

Both are domed. Ive tried every bottom die and the case is centre to the top die but the crystal doesnt just sit in the hole due to the 0.02mm from what i can see. The pressure I put down just causes it to break when i think i have it centred. 

[GuyMontag]

That aluminum die you are showing isn't a domed die. It should look like this:

[easthammer]

1 minute ago, GuyMontag said:

That aluminum die you are showing isn't a domed die. It should look like this:

Potentially i am using the wrong technique then, apologies i am new to replacing high domed crystals. From what ive seen, I put my watch case on the bottom die and then the top die should just over hang the outer of the domed acrylic and then compress it into the case bezel. 

 

If this is wrong what technique should i use?

[GuyMontag]

For an acrylic crystal it should look like the below. You place the crystal on the lower domed die, bring the upper die down to the crystal and compress it slightly, raise the watch case and compress the crystal slightly until you can feel the crystal click into the case and then while maintaining a slight upwards pressure with the case, back off the upper die.

 

 

 

I glued one of those felt things that goes on the bottom of furniture to the domed die so it doesn't scuff the inside of the crystal. If your press takes the M6 style that screw on, Cousins sells the Bergeon bakelite domed dies individually. I only bought the 14, 16, and 20mm dies and those have worked for me so far.

 

If you have taken Mark's course he has a bonus video covering this.

Edited March 29, 2023 by GuyMontag

[easthammer]

16 minutes ago, GuyMontag said:

For an acrylic crystal it should look like the below. You place the crystal on the lower domed die, bring the upper die down to the crystal and compress it slightly, raise the watch case and compress the crystal slightly until you can feel the crystal click into the case and then while maintaining a slight upwards pressure with the case, back off the upper die.

 

 

 

I glued one of those felt things that goes on the bottom of furniture to the domed die so it doesn't scuff the inside of the crystal. If your press takes the M6 style that screw on, Cousins sells the Bergeon bakelite domed dies individually. I only bought the 14, 16, and 20mm dies and those have worked for me so far.

 

If you have taken Mark's course he has a bonus video covering this.

This makes a lot of sense and will buy the dies. Thanks very much for your help 

[VWatchie]

Looking at the dies in the first post I took for granted you were trying the press in an armoured watch crystal (with a tension ring on the inside of the crystal). In that case, your dies were the right ones to use.

In this video, I show how I do it.

Anyway, for a non-armoured watch crystal, the method described by @GuyMontag is the way to go!

[mikepilk]

12 hours ago, VWatchie said:

So, 0.02mm or 0.2mm? If it's 0.2mm larger than the hole I believe that would explain why you can't get it in. 0.1 mm larger than the hole I believe is the common practice, and even then that can sometimes be very hard to fit.

I like the grease idea. Never thought of that.

For acrylic glasses Sternkreuz recommend 0.2mm to 0.5mm larger than the hole, but this depends on the size of the crystal. I use the Bergeon claw tool and usually use 0.2 - 0.3mm larger diameter. 

8836_Sternkreuz R19 Snap In Glasses Pages 12 to 29.pdf

Edited March 30, 2023 by mikepilk

[VWatchie]

12 hours ago, mikepilk said:

For acrylic glasses Sternkreuz recommend 0.2mm to 0.5mm larger than the hole

Good to know! 

I believe, 0.1mm is what's recommended for armoured glasses (which I initially and incorrectly thought was what the OP was asking about).