[saturnine]

Comrades, I am in need of help understanding Vostok Amphibian crystals.

I have a Soviet 470 which I acquired recently & decided to give it a thorough cleaning. In so doing, I removed the crystal and cleaned the inside rim of the case where the crystal sits. After polishing the crystal I reinserted the tension ring within the crystal and reassembled the case using all the same parts save for new crown & caseback gaskets. I then tested for water resistance in 5" of water - sadly the empty case took on water within seconds. I'm rather certain the ingress is at the crystal as the crown & caseback were quite tight. I took it apart, flipped the tension ring within the crystal around the other way & reinstalled with crystal press, hearing a satisfying snap in the process. Same water test, same results. I went through this a few more times, always with the same results. Very sad.

Next I dug out some of my spare amphibian crystals and tried to insert them. I couldn't get a single one to fit, their diameter was too great. I measured the extant crystal - 31.1mm. All the spare crystals I have measure 31.5/6/7mm. What the Stalin? That's quite a difference! Now, I'm not entirely certain where I have acquired some of these crystals, I know 1 or 2 have been sent along with dials from Amil, but they all exhibit the same Amphibian thickness with the same dome & generally the same height. The only size listing for an Amphib. crystal I can locate is from Favinov at 31.2mm for a new one.

Setting aside my confusion over crystal sizing, how can I reinstate a measure of WR? While I was cleaning the crystal rim on the case, I was removing white powder which I assume is old glue. Is it necessary to glue these in to retain WR? I did not believe this to be the case, but if so, is a substantial bead of GS Hypo cement sufficient? I won't be scuba diving but I don't want to worry about every little drop of water, which I currently would. I really don't want a new crystal as they have a pronounced shoulder from the crystal to the bezel; these Soviet crystals have a nice smooth transition (no shoulder) from crystal to bezel.

Also, the tension ring appears to be beveled on one edge, what is the proper positioning of this?

Help me Obi-WUS, you're my only hope!

Patient Zero:

 

[kev80e]

I'm not sure of the official exact size but I think it's probably either the wrong crystal or in such an old watch , I have read somewhere that the case could be slightly warped or damaged over time. Doesn't help you much but I'd see if I could find a slightly bigger crystal.

 

[antilucem]

I'm not sure of the official exact size but I think it's probably either the wrong crystal or in such an old watch , I have read somewhere that the case could be slightly warped or damaged over time. Doesn't help you much but I'd see if I could find a slightly bigger crystal.

I happen to have a spare 'new type' Amphibian crystal from Meranom and the tension ring so I measured them.

Crystal was 31.29

Ring was 29.19 (could have slightly larger as it tried to compress when measured but I took several readings).

I would be very interested to hear how you solve the problem and actually what the issue was.

Hope this helps.

Barry.

 

[saturnine]

The more I read about crystals the less inclined I am to believe that is the culprit of the water ingress. It has the tension ring installed and the crystal snaps in snugly. In fact, when installing the crystal with only my thumbs, I couldn't get it to seat evenly - I could only do so with a press.

Do new gaskets need to be "broken in" before providing proper WR? I didn't replace the crown tube gasket but that shouldn't matter... Right?

I am just very baffled and frustrated by this, especially considering how quickly it takes on water.

 

[engblom]

The gaskets will work directly.

You could put it under water without movement and check if you see bubbles coming. Then you should be able to locate the culprit.

 

[OrangeOrange]

The more I read about crystals the less inclined I am to believe that is the culprit of the water ingress. It has the tension ring installed and the crystal snaps in snugly. In fact, when installing the crystal with only my thumbs, I couldn't get it to seat evenly - I could only do so with a press.

Do new gaskets need to be "broken in" before providing proper WR? I didn't replace the crown tube gasket but that shouldn't matter... Right?

I am just very baffled and frustrated by this, especially considering how quickly it takes on water.

I'd change the crown gasket too. That one probably has the most wear. However, changing all your gaskets does not guarantee water resistance, the case could be slightly pitted or something so it would not be water resistant anymore. It's an old watch so I wouldn't go swimming with it anyways.

 

[Rimmed762]

Amphibia with new proper crystal and new gaskets will be (IMHO) waterproof. If the caseback isn't warped.

I have never seen pitted Amphibia. Or not even pitted Komandirskie (from critical places) but I am sure there are some.

 

[Mr. Wolf]

I'm really interested about this too because I also need to change the crystal and want it to be waterproof. One thing you can do to be sure whether it's the crystal or something else is filling the case with water upside down without the caseback and see where it leaks. Maybe it's the crown tube.

 

[saturnine]

I'd change the crown gasket too. That one probably has the most wear. However, changing all your gaskets does not guarantee water resistance, the case could be slightly pitted or something so it would not be water resistant anymore. It's an old watch so I wouldn't go swimming with it anyways.

The crown gasket is new, it's the crown tube gasket that was not changed.

 

[VWatchie]

I'm in the same situation but I've decided to draw the conclusion that my watch case is now water resistant despite containing some water. Yes I agree; that certainly sounds like a contradiction in terms but please let me explain!

So, here's the story… I'm restoring this vintage Amphibian:

Since the crystal contained some cuts along the edge (hardly visible in the picture) that wouldn't dissolve using Polywatch, I decided to replace it and ordered a spare from Meranom. At the same time I took the opportunity to order a rubber seals set.

BTW, I measured the diameter of both the original and the replacement crystal with my calipers and (as I suspected and hoped) they measured exactly the same; 31.1 millimeters as can be seen here:

However, when I had removed the crystal I got the idea to first try to remove the cuts using Autosol. It worked perfectly, and I then finished it off with Polywatch.

Now, with the original crystal looking like new there was no need to use the spare. However, as I wasn't convinced the crystal would be water resistant I decided to test it first. So I assembled the case without the movement and sunk it in a bucket of water. For the first few hours it looked like a success; there wasn't a trace of water on the inside. However, after about 24 hours the inside was soaked and looked like this:

(The three white strips under the crystal is water drenched KLEENEX which I put inside the case to be able to more easily detect any water ingress).

Needless to say, the test was a failure. Taking off the case back and studying the inside of the case I realized the water ingress had come, at least mainly, from the case back despite having used the new rubber seals set. I realized that I had used way too little silicone grease on the rubber gaskets and decided to start all over, this time following the instructions in this video.

So back in the bucket of water it went. Again, after a few hours there wasn't a trace of any water, but again after 24 hours a mist and some tiny drops of water could be seen on the inside of crystal.

However, carefully studying the rest of the inside of the case by looking through the crystal using a magnifier, I noticed the rest of the case seemed completely dry. So as expected, no water ingress from the case back or crown. At this point I was beginning to suspect condensation; that the air trapped inside the case had been cooled by the surrounding water in the bucket and had released its water. Now, if condensation was the actual cause, keeping it in the water filled bucket for another 24 hours or so should reveal the answer. Any further water ingress would definitely add to the mist and drops of water on the inside of the crystal, whereas if it was a matter of condensation the amount of mist and water drops would remain the same.

Come the next day and I compared the accumulation of mist and water drops with the image above and couldn't see a any difference whatsoever. The mist looked no thicker and no thinner. The drops of water were in the exact same places and were no thicker or thinner.

My final conclusion is that the mist and water on the inside of the crystal must be the result of condensation. That is, that the watch is indeed water resistant but not immune to condensation.

I realize that my skills in watch making and physics leave a lot to be desired and that I therefore could be wrong, but I sort of feel or believe that I have a strong case. If someone could prove me wrong or put some serious doubt in my mind I'd really appreciate it!

Hope this was helpful!

 

[saturnine]

Thank you for this. Though it seems your last sentence was cut off mid-thought and leaves me in great suspense.

 

[VWatchie]

Thank you for this. Though it seems your last sentence was cut off mid-thought and leaves me in great suspense.

Hmm... That's funny! It looks perfectly alright to me. Anyway is the following quote what you see as my last three sentences?

"My final conclusion is that the mist and water on the inside of the crystal must be the result of condensation. That is, that the watch is indeed water resistant but not immune to condensation.

I realize that my skills in watch making and physics leave a lot to be desired and that I therefore could be wrong, but I sort of feel or believe that I have a strong case. If someone could prove me wrong or put some serious doubt in my mind I'd really appreciate it!

Hope this was helpful!"

 

[VWatchie]

.

 

[Lokifish]

Here's what I've learned testing my Amphibias and 'dirskies, maybe it will help.


Casebacks with new gaskets needs to be tightened in stages (tighten well, go back hours/days later and tighten again)

While all my watches will pass a 5ATM immersion test, they fail a 5 ATM bubble test almost every time. (all pass a steam box test as well)

Using a sponge cut to fit the inside of the watch, then dusting it with powdered food or fabic dye, is indispensable when trying to track down points of ingress.

 

[herdingwetcats]

To be really certain about the condensation issue, you could repeat the last test, but fill bucket with warm water. I watched the good video you mentioned on this forum, Comrade Swexet, and was answered with some howls of horror fromvComrades who felt dialectic silicone grease was totally wrong, and one must use silicone dive watch grease. For all I know, these are really the same, just throwing it out there. The crown tube has a gasket and also a metal washer which faces the gasket in the crown. I read that replacing these is wise, as the metal washer can easily be mangled: could this be the problem? Best of luck!

 

[VWatchie]

Here's what I've learned testing my Amphibias and 'dirskies, maybe it will help.

Casebacks with new gaskets needs to be tightened in stages (tighten well, go back hours/days later and tighten again)

While all my watches will pass a 5ATM immersion test, they fail a 5 ATM bubble test almost every time. (all pass a steam box test as well)

Using a sponge cut to fit the inside of the watch, then dusting it with powdered food or fabic dye, is indispensable when trying to track down points of ingress.

Thanks! Yes, it makes sense that the case back gasket when new will gradually budge under the pressure of the case back. So it sounds like a very good idea! In this respect a screw down case back has an advantage as it won't need to be re-tightened.

What's a "bubble test"?

Well that sounds like a good method, and I guess warm water is necessary to avoid condensation.

 

[VWatchie]

To be really certain about the condensation issue, you could repeat the last test, but fill bucket with warm water. I watched the good video you mentioned on this forum, Comrade Swexet, and was answered with some howls of horror fromvComrades who felt dialectic silicone grease was totally wrong, and one must use silicone dive watch grease. For all I know, these are really the same, just throwing it out there. The crown tube has a gasket and also a metal washer which faces the gasket in the crown. I read that replacing these is wise, as the metal washer can easily be mangled: could this be the problem? Best of luck!

I have no idea and didn't even notice or consider what kind of grease that was used in the video, so it could be worth considering. Personally I used grease on a tube with the printing "silikonfett www.watch-tool.de". I bought it from a German watch tool site a long time ago and just assumed it was "good German silicone grease" for watch gaskets ;-).

 

[Lokifish]

Thanks! Yes, it makes sense that the case back gasket when new will gradually budge under the pressure of the case back. So it sounds like a very good idea! In this respect a screw down case back has an advantage as it won't need to be re-tightened.

What's a "bubble test"?

Well that sounds like a good method, and I guess warm water is necessary to avoid condensation.

Bubble test example video

Now a straight immersion test would have you place the watch in the water prior to increasing pressure, then leave the watch submerged under pressure for a couple days. That's usually done without a movement in the case for obvious reasons.

 

[Cafe Latte]

Make sure the watch case is assembled in dry conditions if there is little to no water in the air in the case it cant condense. If you have an aircon unit put it on in the room for some time before the job as this will reduce the humidity.
Chris

 

[saturnine]

24h, here are instructions on building your own 3 bar tester if interested.

http://www.christopherwardforum.com/viewtopic.php?t=10816