Crown o-ring gaskets (Longines and Omega)

[ManSkirtBrew]

I'm working on a friend's Omega and Longines, and in both the crown o-rings had turned to goo. I was able to clean most of it out with an oiler, and dissolved the rest out with hairspring dip.

But just now I came across this thread talking about pushing the washer into the crown, and I may give that a go, but I'm trying to figure out how to find the right o-rings. I was wondering if I did find the correct one if I could sneak it in there without having to mangle the washer.

I know the advice is to just buy a new crown, but especially the Omega has sentimental value, so I'd like to replace as few bits as possible.

I'm planning to measure the outside of the crown tube to get the ID, and the inside of the crown once I get the washer off to get the OD, but I figured I'd ask in case anyone has a size listing in their pocket.

Omega case: 168.046-368.846

Longines case: 2579-343

[Klassiker]

The method of doming the washer to remove it, then flattening it out again to sit tight after replacing the o-ring works well. No mangling involved. You will struggle to get the right size of o-ring through the gap. I'm not saying it's impossible, but the potential for damage is great.

[ManSkirtBrew]

On 6/5/2024 at 1:58 AM, Klassiker said:

he method of doming the washer to remove it, then flattening it out again to sit tight after replacing the o-ring works well. No mangling involved.

I gave it a go tonight on the Longines crown. I grabbed the smallest domed stake that fit over the center bolster and started tapping away.

 

After much tapping, instead of doming the washer, it pushed it off the lip it was sitting on and wedged it down in the crown.

I was able to pry up the chrome around the lip, but now I can't get the washer to budge.

Guess we're buying a new one. At least it was a learning experience, although I'm not quite sure what I learned

 

Edit: I did win in the end, but at the cost of galling the bejeezus out of the inside of the crown. I'm on the hunt for a replacement.

 

Edited June 19, 2024 by ManSkirtBrew

[HectorLooi]

Since posting that thread, I've come across a couple of crowns that the washer did not come off. I think it has to do with the width of the ledge under the washer. If the ledge is too wide, the washer won't dome nicely. 

I'm currently working on an idea to grip the inside of the washer and pulling the washer out of the crown, something like a internal bearing puller. 

[Waggy]

Just thinking, there must be something nasty out there that would dissolve the o-ring, or maybe heat - all we need to do is make it brittle or crumbly so we can get it out of there?

Maybe a soak in actone or hot vinegar (acetic acid) for a few days:

 

[RichardHarris123]

4 minutes ago, Waggy said:

Just thinking, there must be something nasty out there that would dissolve the o-ring, or maybe heat - all we need to do is make it brittle or crumbly so we can get it out of there?

Maybe a soak in actone or hot vinegar (acetic acid) for a few days:

 

That's OK for removing the gasket but it will be difficult getting a new one in. 

[Neverenoughwatches]

8 hours ago, ManSkirtBrew said:

At least it was a learning experience, although I'm not quite sure what I learned

 

you did learn something msb , not to hit so hard. In @HectorLooi 's defence i think the idea is to tap tap, check for release , tap tap check for release etc etc.  At some point it should just come free if it doesn't then stop re-think before destruction.

4 hours ago, HectorLooi said:

Since posting that thread, I've come across a couple of crowns that the washer did not come off. I think it has to do with the width of the ledge under the washer. If the ledge is too wide, the washer won't dome nicely. 

I'm currently working on an idea to grip the inside of the washer and pulling the washer out of the crown, something like a internal bearing puller. 

3 very small fish hooks  Hector

20 minutes ago, Waggy said:

Just thinking, there must be something nasty out there that would dissolve the o-ring, or maybe heat - all we need to do is make it brittle or crumbly so we can get it out of there?

Maybe a soak in actone or hot vinegar (acetic acid) for a few days:

 

I have had the problem a few times of solvents softening and swelling the gasket so it wont fit over the tube. I once had a stem that just would not go back in after casing up, tearing my hair out until i realised it was the swollen gasket would not fit over the case tube. Anything petroleum based will soften it right up. Ps. Scott , off topic but i really like the Kerosene,trialled and tested by hand cleaning its bloody marvellous, takes a bit of rinsing off ( not much really, break cleaner zaps it pretty quick ) but the finished clean is fantastic. 

25 minutes ago, RichardHarris123 said:

That's OK for removing the gasket but it will be difficult getting a new one in. 

Thats what the thread was about getting another of the right size back in.  Whatever you do folks, dont put your crown and stems in the solvent cleaners, it fooks the gaskets right up.

5 hours ago, HectorLooi said:

Since posting that thread, I've come across a couple of crowns that the washer did not come off. I think it has to do with the width of the ledge under the washer. If the ledge is too wide, the washer won't dome nicely. 

I'm currently working on an idea to grip the inside of the washer and pulling the washer out of the crown, something like a internal bearing puller. 

When i fit kitchens i use an allen key to pull off the kick boards, insert turn and pull.   With that in mind, 3 bent needles fed into the crown once the old gasket is out spaced evenly apart around the perimeter and then gripped just above the crown thread with pliers and pull. Sounds very fiddly and I'm sure it is, but it might save on the renewal of an expensive crown.

[Neverenoughwatches]

10 hours ago, ManSkirtBrew said:

I gave it a go tonight on the Longines crown. I grabbed the smallest domed stake that fit over the center bolster and started tapping away.

 

After much tapping, instead of doming the washer, it pushed it off the lip it was sitting on and wedged it down in the crown.

I was able to pry up the chrome around the lip, but now I can't get the washer to budge.

Guess we're buying a new one. At least it was a learning experience, although I'm not quite sure what I learned

 

Edit: I did win in the end, but at the cost of galling the bejeezus out of the inside of the crown. I'm on the hunt for a replacement.

 

Looks like the stake was too wide to dome the washer enough before hitting the rim. I collect old stakes for just such situations, in fact i modified the outside chamfer of one yesterday to narrow it to better flatten out a staff rivet,  you can never have enough stakes to modify. 

[Tudor]

Drill rod is good to keep on hand to make stakes from...

[Waggy]

Just kicked off a little experiment..... watch o-rings in acetone:

2 old crowns I had kicking around, placed in acetone

Plan on tidying my workspace today so I am sure to come across a couple more crowns that I can test in vinegar (acetic acid)