Over / under tightening

[sgnu]

How do you know if it's too tight or not enough?

[SrFADE]

Originally Posted by sgnu

How do you know if it's too tight or not enough?

This question has the potential to get some unexpected answers.

[sleddog]

If you're talking about the crown, finger tight is all....
As in when it stop turning without forcing, don't turn it any further!

[pereiraex]

Originally Posted by sgnu

How do you know if it's too tight or not enough?

I use pliers to make sure the crown on my GMT IIc is solid tight before I go swimming. Better be safe than sorry, rather a bit of damage on the crown than having water on the gears and dial faces.

[sleddog]

Originally Posted by pereiraex

I use pliers to make sure the crown on my GMT IIc is solid tight before I go swimming. Better be safe than sorry, rather a bit of damage on the crown than having water on the gears and dial faces.

Always one in the crowd!

[Rolex addict]

Originally Posted by pereiraex

I use pliers to make sure the crown on my GMT IIc is solid tight before I go swimming. Better be safe than sorry, rather a bit of damage on the crown than having water on the gears and dial faces.

A torque wrench is better so you can be exact on how overtight it is.

[sensui]

Originally Posted by SrFADE

This question has the potential to get some unexpected answers.

Subscribed for these answers......yeah....it's a slow day.

[droptopman]

Oh my...LOL

All these years and I had never thought about using pliers to tighten the crown.

Modern crowns have a great set of gaskets so do not need to really be "tightened" just finger tight.

[brandrea]

I tighten until the crown just makes contact - lightly finger tight is all.

[brandrea]

Originally Posted by pereiraex

I use pliers to make sure the crown on my GMT IIc is solid tight before I go swimming. Better be safe than sorry, rather a bit of damage on the crown than having water on the gears and dial faces.

and ... I'm certain you are joking

[pereiraex]

Originally Posted by droptopman

Oh my...LOL

All these years and I had never thought about using pliers to tighten the crown.

Modern crowns have a great set of gaskets so do not need to really be "tightened" just finger tight.

I disagree... I had a old submariner that was "finger tight" and took it for a shallow dive (50m). When I took it into the RSC thinking it could be repaired... well, let's just say they returned it back to me with a sincere apology.

[Cerachrom12]

Originally Posted by pereiraex

I disagree... I had a old submariner that was "finger tight" and took it for a shallow dive (50m). When I took it into the RSC thinking it could be repaired... well, let's just say they returned it back to me with a sincere apology.

If the seals are shot, no amount of crown tightening will make the watch waterproof. And usually the crystal gasket gIves out first.

[sleddog]

Originally Posted by pereiraex

I disagree... I had a old submariner that was "finger tight" and took it for a shallow dive (50m). When I took it into the RSC thinking it could be repaired... well, let's just say they returned it back to me with a sincere apology.

Why, cause it flooded?

If you did infact use a pair of pliers and that's what happened, most likely you were the cause...
There are other seals to fail also. Caseback and crystal, not just the crown.

[J!m]

Engineer 's know:

Tighten until it breaks and then back off 1/4 turn.

[droptopman]

Originally Posted by pereiraex

I disagree... I had a old submariner that was "finger tight" and took it for a shallow dive (50m). When I took it into the RSC thinking it could be repaired... well, let's just say they returned it back to me with a sincere apology.

If you read my post, I said a modern crown. Although my 50 year old Sub with a 700 twin lock crown passed a pressure test recently and was only finger tight.

[Old Expat Beast]

It's designed to be closed finger tight. Forcing the crown closed with pliers will do more harm than good.

[watchdawg]

Impact wrench works perfectly

[DRKBC]

Originally Posted by watchdawg

Impact wrench works perfectly

Good call! you can re-torque your lug nuts at the same time.

[natosub]

When you guys say "finger tight", do you mean finger tight against the case? There seem to be about 2 full turns to the crown:

• Smooth for about 1 3/8 turns
• Light resistance (I assume when you engage the seal in the crown)
• Another 5/8 turn until the crown meets the case

Not to over-analyze, but does finger-tight mean two full turns lightly seated against the case, or just past the point of resistance engaging the seal; say a quarter turn shy of the case?

Don't want to overtighten, but don't want to risk water infiltration either!

[J!m]

Check out the Parker o-ring catalogue. I used to refer to the printed version (still have it) for designing o-ring grooves. All you never wanted to know about optimal compression, static versus rotating versus sliding applications (and they are all slightly different).

Then you can simply make a jig to hold the case and a dial indicator to determine exact o-ring compression as dictated by the experts. Simple.

[Tools]

Originally Posted by pereiraex

I disagree... I had a old submariner that was "finger tight" and took it for a shallow dive (50m). When I took it into the RSC thinking it could be repaired... well, let's just say they returned it back to me with a sincere apology.

What do you disagree with?

If your watch leaked, the gasket in the crown was likely not the culprit as that is not a primary water seal, it is the O-rings around the stem inside. Typically water enters through the crystal to case seal before anywhere else.

Originally Posted by natosub

. . Not to over-analyze, but does finger-tight mean two full turns lightly seated against the case, or just past the point of resistance engaging the seal; say a quarter turn shy of the case?

Don't want to overtighten, but don't want to risk water infiltration either!

The crown should never contact the case. If it does then the crown gasket is not contacting the top of the tube..

[LuminousMaximus]

Originally Posted by Tools

What do you disagree with?

If your watch leaked, the gasket in the crown was likely not the culprit as that is not a primary water seal, it is the O-rings around the stem inside. Typically water enters through the crystal to case seal before anywhere else.



The crown should never contact the case. If it does then the crown gasket is not contacting the top of the tube..

That's good to know!

[Andad]

You are correct Rob and there is too much misinformation on these threads (some in jest) but I will try one more time.

A few years ago Rolex stated on their website that the Triplock seal was rated to 500 Bar with the crown unscrewed. A finger tight seal on the crown is not going to do much at 7400psi?
The finger tight crown is there to prevent operation of the crown when submerged.

As confirmation of this consider the pushers on a Daytona.
They are rated to 100m (plus a margin) and have no screw down seals.
The internal stem seals do the work.
Again the screw down function it there to prevent operation at depth.

The crown should not touch the case when screwed in.

[Old Expat Beast]

Originally Posted by directioneng

You are correct Rob and there is too much misinformation on these threads (some in jest) but I will try one more time.

A few years ago Rolex stated on their website that the Triplock seal was rated to 500 Bar with the crown unscrewed. A finger tight seal on the crown is not going to do much at 7400psi?
The finger tight crown is there to prevent operation of the crown when submerged.

As confirmation of this consider the pushers on a Daytona.
They are rated to 100m (plus a margin) and have no screw down seals.
The internal stem seals do the work.
Again the screw down function it there to prevent operation at depth.

The crown should not touch the case when screwed in.

Makes you wonder why modern non-diver Oysters like the Explorer I & II, GMT, Datejust, etc are only rated to 100m. Even my wife's tiny, acrylic Tudor mini-sub is rated to 200m.

[padi56]

Originally Posted by pereiraex

I disagree... I had a old submariner that was "finger tight" and took it for a shallow dive (50m). When I took it into the RSC thinking it could be repaired... well, let's just say they returned it back to me with a sincere apology.

Would not call a 50m dive a shallow dive.

[Ian Macdermott]

Originally Posted by padi56

Would not call a 50m dive a shallow dive.

I was thinking that.

[Andad]

A 50mm dive is nothing Pete.

Auto correct?

[padi56]

Originally Posted by directioneng

A 50mm dive is nothing Pete.

Auto correct?

It is if you do not have the qualifications and experience most recreational divers today would stick to 40m or less but agree 50mm is hardly enough to get your face wet..

[Tomas Eriksson]

Originally Posted by Old Expat Beast

Makes you wonder why modern non-diver Oysters like the Explorer I & II, GMT, Datejust, etc are only rated to 100m. Even my wife's tiny, acrylic Tudor mini-sub is rated to 200m.

The case back is the main reason. Your wife Tudor has thicker case back that can handle a lot more pressure before it starts to deform.

[Old Expat Beast]

Originally Posted by Tomas Eriksson

The case back is the main reason. Your wife Tudor has thicker case back that can handle a lot more pressure before it starts to deform.

So the Tudor Mini-Sub's acrylic crystal can withstand more pressure than, say, the Explorer's steel case back?