Pressure testing A7750 in my Carrera

[TagMatty]

Hi... a quick question to anyone that ownes a Tag Chrono (or any chrono for that matter). Has anyone pressure tested their chrono with a A7750?

I've read through this http://www.rwg.cc/members/index.php?showto...ressure+testing and its made me a little cautious to go ahead and pressure testing mine.

Comments anyone??

[Toadtorrent]

There are a couple ways to pressure test...some don't involve water at all so there's no risk of water penetration.

You can do the home brew pressure tester (do some research to find the post...can't remember where it is off hand) using a Nalgene bottle and bike tube parts...or go to a watchmaker/repair guy in a shopping mall. A test costs between $30-$50 usually. Even the tests with water are safe for the watch if done correctly.

BTW...you test the case really...and not the A7750 movement.

[TagMatty]

There are a couple ways to pressure test...some don't involve water at all so there's no risk of water penetration.

You can do the home brew pressure tester (do some research to find the post...can't remember where it is off hand) using a Nalgene bottle and bike tube parts...or go to a watchmaker/repair guy in a shopping mall. A test costs between $30-$50 usually. Even the tests with water are safe for the watch if done correctly.

BTW...you test the case really...and not the A7750 movement.

lol no no no... there will be no "home brew pressure test"

I'm going to take my watch into a watch maker and have him do his thing. I'm fully aware that the test is on the case and not the movement. I assumed that when caution was given in presure testing chronos it was due to the higher number of penetration's in the watches case and therefore it's a little harder for rep fractories to ensure proper water resistance... if that makes any sense!!!

Correct the newbie if i'm wrong

[Toadtorrent]

lol no no no... there will be no "home brew pressure test"

I'm going to take my watch into a watch maker and have him do his thing. I'm fully aware that the test is on the case and not the movement. I assumed that when caution was given in presure testing chronos it was due to the higher number of penetration's in the watches case and therefore it's a little harder for rep fractories to ensure proper water resistance... if that makes any sense!!!

Correct the newbie if i'm wrong

You got it!! I've never had one test to 5atm...others have had consistent luck. That's the world of the rep...luck of the draw.

Caseback, crystal and crown are generally fine...the chrono pushers as you have said are the weak point. Some of the current reps have the double gaskets on the pushers (which is all I have on the pushers of my camera scuba cases) so they should be fine...but often tolerances in manufacturing may lead to leakage. The designs themselves are sound...the tolerances and QC/QA (e.g. forgotten or dry gaskets) are more common in the rep world.

Here's the home brew pressure tester...cool. I've wanted to try it...have the parts, but haven't had the time to build it yet:

Home Brew Pressure Tester With Nalgene Bottle

[rek001]

So is there any method to waterproof the chrono pushers in addition to gaskets?

How about silicon grease, or would the grease mess up the mechanics of the pushers?

[Shundi]

I used WD 40 on caseback and crown gaskets but I think I read that silicone can cause the gaskets to expand or something like that so I've taken to using the grease you can get from Ofrei. I just unscrew the caseback and remove the stem then grease up (in the case of a Rolex rep) the caseback and crown/stem gaskets, carefully reinsert the stem/make sure it's working (toughest part for a noob like myself) and replace the caseback. My SeaDweller is been on shallow(ish) dives down to 50-75ft and in the shower/pool and is perfectly fine...I usually reapply the grease every 6 months or so.

[gbc]

I used WD 40 on caseback and crown gaskets but I think I read that silicone can cause the gaskets to expand or something like that so I've taken to using the grease you can get from Ofrei. I just unscrew the caseback and remove the stem then grease up (in the case of a Rolex rep) the caseback and crown/stem gaskets, carefully reinsert the stem/make sure it's working (toughest part for a noob like myself) and replace the caseback. My SeaDweller is been on shallow(ish) dives down to 50-75ft and in the shower/pool and is perfectly fine...I usually reapply the grease every 6 months or so.

Actually rubber doesn't react to silicon as it is inert. It reacts to mineral based oils. Thats the reason you seeing warnings on condom packaging not to use mineral oils such as petroleum jelly as a lubricant .... it damages the entegrity of the seal

One should also not use WD-40 as it was never designed as a lubricant to begin with. The designation WD actually refers to Water Displacer - 40

[crwolf79]

I just had my new Tag Link Chrono resized at the mall at one of those Dakota Watch kiosks. I know, the travesty. Anyway, they had a little flyer that described their pressure testing service, and recommended that anyone do it when replacing a battery (what's a battery...) Anyway, I asked what it cost, and he said $5. No water involved. Unfortunately, he said that his read-out on the thing was broken, and it only indicated pass/fail, but not the atmospheric pressure that it made it to. So I opted to save my $5 and do it at a different mall when I came across another Dakota Watch place.

I haven't even gotten my Tag wet yet... I'm a little concerned about the water-proof ability of the pushers, and the crown.