Removing oring from waterproof crowns

[HectorLooi]

Recently a new member asked how to remove the oring from a waterproof crown. He was redirected to an old YouTube video where the washer was forced out by stuffing in multiple orings into the groove in the crown until it bulged the washer out.

I always thought that method was a waste of good orings.

So I toyed around with the idea of pushing in the washer with a domed staking tool. I first had to soften the old oring by soaking it in acetone for about an hour. Then I selected a domed staking tool with a centre hole just slightly larger than the hub of the crown. The washer is quite malleable and was easily domed in until the rim was smaller than the lip holding it in.

The next task is to find an oring of the correct size to replace the damaged one.

[nickelsilver]

That's excellent! I'll be curious if the ring flattens out well enough to re-use. In the past I just pried out the ring and made a new one; this looks like much less frustration and safer overall.

[HectorLooi]

I managed to find an oring that fits the crown. The washer was surprisingly easy to flatten back.

 

[Malocchio]

That looks a lot easier than the current best practice. Was there any material over the washer like there is in old Seikos? In this pic you see that a strip of metal got torn away when I pushed the washer out. That was pretty nerve wrecking but turned out great. I used a stump from the Horia clone. Now I wonder why did I use a bench vice and not the jewel tool for the pressing.

[HectorLooi]

The rim of the crown was burnished over the washer, forming a kind of lip. That lip is what appears to be torn in your photo. 

I'm not sure if my method would work on all crowns. I might have to modify an old stake to form a more pointed tool for smaller diameter crowns.

But it worked very well on this crown from a Sekonda 30 jewel automatic watch with a Poljot 2616.1h movement. It sure beats all the other methods I've tried.