Rainbow effect / smudge mark on Submersible reps and solution

[jitai]

I have a modded PAM24A but little do I know about that it comes with a sandwiched crystal until Zigmeister pointed it out to me.

Well. The crystal was fine at first until recently when a rainbow effect or smudge mark started appearing at the edge of the crystal and across the cyclop. It can't be seen when you look at the crystal directly but they show up at some angles.

I did some research on my own and realised that the crystal on most PAM24 reps with A7750 actually comes with 2 piece. The upper layer crystal is the sapphire with slight rounded domed top while the lower layer is a piece of glass (mineral I guess). The upper layer sapphire is where the cyclop is installed and the lower layer will have a hole to let the cyclop sit in. The rainbow smudge mark is caused by the melting of the glue holding the sapphire and mineral glass together.

If yours is currently ok. I will suggest that you avoid leaving the watch under sunlight or rush it with hot water as it this glue react with the applied temperature.

Here's a pics to show the problem. Notice the smudge mark across the cyclop?

Below are some solution I thought that it will work.

1. Source for a slight domed crystal with flat base and add a chieftang's cyclop

Result - not possible as the there is no offering for a sapphire crystal for the required diameter and thickness.

Even if it is possible to find one, the thickness of the crystal with the cyclop will obstruct the minute hand.

2. Remove the existing sandwiched crystal, open them up and applied UV clear glue.

Result - not possible as the thickness of the glue need to be uniformly or evenly applied and not likely to be done by hands.

Even if it can be done by super steady hands, dust particles will be attraced on the glue surface.

Just as I was about to give up.

I was lucky that I manage to find a low cost PAM24 rep with 21J movt. When my watchsmith remove the crystal. Below are what we discovered

1. The crystal is not sapphire but mineral glass (expected for the price) but hey it comes as a whole piece and not sandwiched

2. Cyclop is separately installed on this version but need to realign again.

3. the mineral glass diameter is larger than the sandwiched crystal.

Mixture of good and bad news. Good news is it is very unlikely I will encounter the rainbow smudge problem anymore if the mineral glass can be used.

Bad news is, the mineral glass cannot be fitted as its diameter is larger.

Luckily, my watchsmith told me he is able to reduce the diameter of the mineral glass. It will not be possible if it is a sapphire as the material will be harder. However, there is some risk that the mineral glass will crack if it is unable to take the high temperature created from the buffing machine.

Well. I am game so I ask him to proceed.

The result?

Problem solved and bye bye to rainbow smudge for good.

My PAM24A is really modded to the max and bullet proof now.

Hope this information is useful for all PAM24 sub owners.

Edited June 21, 2009 by jitai

[coolfire]

Well done buddy

Enjoy your beloved 24A & wear it in good health too!

[blackbard]

Good work and write up. Its a good thing you found someone local to work on the piece...

I have a modded PAM24A but little do I know about that it comes with a sandwiched crystal until Zigmeister pointed it out to me.

Well. The crystal was fine at first until recently when a rainbow effect or smudge mark started appearing at the edge of the crystal and across the cyclop. It can't be seen when you look at the crystal directly but they show up at some angles.

I did some research on my own and realised that the crystal on most PAM24 reps with A7750 actually comes with 2 piece. The upper layer crystal is the sapphire with slight rounded domed top while the lower layer is a piece of glass (mineral I guess). The upper layer sapphire is where the cyclop is installed and the lower layer will have a hole to let the cyclop sit in. The rainbow smudge mark is caused by the melting of the glue holding the sapphire and mineral glass together.

If yours is currently ok. I will suggest that you avoid leaving the watch under sunlight or rush it with hot water as it this glue react with the applied temperature.

Here's a pics to show the problem. Notice the smudge mark across the cyclop?

Below are some solution I thought that it will work.

1. Source for a slight domed crystal with flat base and add a chieftang's cyclop

Result - not possible as the there is no offering for a sapphire crystal for the required diameter and thickness.

Even if it is possible to find one, the thickness of the crystal with the cyclop will obstruct the minute hand.

2. Remove the existing sandwiched crystal, open them up and applied UV clear glue.

Result - not possible as the thickness of the glue need to be uniformly or evenly applied and not likely to be done by hands.

Even if it can be done by super steady hands, dust particles will be attraced on the glue surface.

Just as I was about to give up.

I was lucky that I manage to find a low cost PAM24 rep with 21J movt. When my watchsmith remove the crystal. Below are what we discovered

1. The crystal is not sapphire but mineral glass (expected for the price) but hey it comes as a whole piece and not sandwiched

2. Cyclop is separately installed on this version but need to realign again.

3. the mineral glass diameter is larger than the sandwiched crystal.

Mixture of good and bad news. Good news is it is very unlikely I will encounter the rainbow smudge problem anymore if the mineral glass can be used.

Bad news is, the mineral glass cannot be fitted as its diameter is larger.

Luckily, my watchsmith told me he is able to reduce the diameter of the mineral glass. It will not be possible if it is a sapphire as the material will be harder. However, there is some risk that the mineral glass will crack if it is unable to take the high temperature created from the buffing machine.

Well. I am game so I ask him to proceed.

The result?

Problem solved and bye bye to rainbow smudge for good.

My PAM24A is really modded to the max and bullet proof now.

Hope this information is useful for all PAM24 sub owners.