Jump to content

Broken Stem Inside Crown...


DJW

Recommended Posts

26 minutes ago, jimtone said:

How much alum to how much distilled water? I've seen this advice for dissolving a stem but never a mixture calibration?

No precise mixture is necessary, you can use at saturation.

By the way, we have a section here where most members like to introduce themselves even before asking questions.

 

Link to comment
Share on other sites

  • 4 weeks later...

Thanks, I'll try to find that introduction section. I've soaked the crown (stainless) in alum for 2 weeks with no effect. I've soaked the crown in pure vinegar for 3 weeks with no effect? I really don't want to soak the stem that is in the movement but think that's the only way to know if it is indestructible. 

Link to comment
Share on other sites

1 hour ago, jimtone said:

Thanks, I'll try to find that introduction section. I've soaked the crown (stainless) in alum for 2 weeks with no effect. I've soaked the crown in pure vinegar for 3 weeks with no effect? I really don't want to soak the stem that is in the movement but think that's the only way to know if it is indestructible. 

 Maybe it's a better quality steel in the stem then many old stems. I have done it on several crown. But not all stems rust. Sometimes you have to bite the bullet and buy a new crown. If you can find one? Not the easiest to find for some watches. 

Link to comment
Share on other sites

On 7/31/2018 at 7:53 PM, jimtone said:

Thanks, I'll try to find that introduction section. I've soaked the crown (stainless) in alum for 2 weeks with no effect. I've soaked the crown in pure vinegar for 3 weeks with no effect? I really don't want to soak the stem that is in the movement but think that's the only way to know if it is indestructible. 

If you are UK-based then I can suggest another acid to try.

Link to comment
Share on other sites

  • 6 months later...

is it possible that my stem is stainless?  This is not working at all for me.  i even put a stem extender in to see if it would work but there is no bubbles or anything happening at all.  I used plenty of the Alum and a small amount of water and heated it up and nothing.  any advice?

Link to comment
Share on other sites

I have the same issue.  no amount of soaking seems to dissolve the stem.  No bubbles at all.  Very dissapointed.  I was really pumped when i saw you can use alum to do this and it's not working for my newer watch.  and its going to cost a lot for a new crown.  so far i can't even find one that will match and the manufacturer has been no help.  

Link to comment
Share on other sites

I don't know if such a thing exists, this small, but if attempting to remove broken studs at a slightly larger scale, a left handed twist drill can be a help.

The idea is to use the drilling action to grab the stud as you drill, and when it grabs, it unscrews it.

However, as I said, I'm not sure where you would get a left handed drill bit small enough to attempt this.

I may have just suggested replacing one intractable problem with an equally intractable one, namely finding such a bit. If anybody knows where to source a left handed bit, then we may have a potential solution. 

EDIT: https://www.ebay.co.uk/itm/GUHRING-HSCO-1-0mm-MICRO-PRECISION-DRILL-WATCH-MAKING-QUALITY-LEFT-HAND-LH-301-1/222408832193?hash=item33c89974c1:g:zAAAAOSwtfhYqIzd

EDIT: These things do exist, so first you will need to figure out what size you need.

Next you will need to figure out if they are worth the expense.

Finally you will need to figure out if you can drill that precisely and with sufficient control not to wreck the bit.

You will also need to kill any thread locker, but that has been covered above.

Edited by AndyHull
Link to comment
Share on other sites

The process I described, along with a few other broken stud removal techniques can be seen here.

https://dannysengineportal.com/broken-bolt-and-stud-removing-tips/

 

Some of these will only work at the macro rather than micro level though. I'm pretty sure they don't make helicoils that small, but I guess you might be able to fabricate something similar.

Edited by AndyHull
Link to comment
Share on other sites

One other trick. Get a very sharp screwdriver bit, the same width as the stud. Tappy-tap-tap it in to the end of the stud, till you have a slot. Now tap the head of the screwdriver, and turn at the same time (this is roughly how an impact driver works).

Don't simply try to turn the screwdriver, cos you will simply strip off the end of the stud. You need to tap down as you turn.

Needless to say, the crown needs to be well anchored while you do this. Protect the ornamental end of the crown against being marred as you whack the end of the stud. Similarly, protect the ridges on the crown against whatever you are gripping it with. Don't crush the crown while gripping it. It would be a shame to ruin the crown while attempting to extract the stud.

The screwdriver bit needs to be really sharp, wear safety goggles, cos there is a pretty good chance you will end up breaking the screwdriver bit (hardened steel is not very happy about being whacked). You also stand a good chance of sending the crown flying, and getting hit in the eye by bits of shrapnel is never fun.

Edited by AndyHull
Link to comment
Share on other sites

  • 1 year later...

Hi folks

I've not been on in a while but, got fed up with hoovering and cleaning everything in sight so I decided to find something to fill my time in while we wait to get our lives back.  I bought this Citizen Eco-Drive, it was partly dismantled but seems to be ok. It was missing the stem and crown, hopefully the ones I have ordered from Cousins should be correct, fingers crossed. I have a crown from another with similar case but the stem is snapped off. Am I overly optimistic or is there any chance of ever getting the broken piece out of the crown, it has broken off flush? 

Many thanks

DaveIMG_0332.thumb.jpg.db6cce4d1e19223bd938499d42363c5d.jpgIMG_0333.thumb.jpg.a0351425ffa72e1ec937879a5c897d04.jpgIMG_0335.thumb.jpg.8c523865b49c28ee046f0dc68d09fdef.jpgIMG_0336.thumb.jpg.fabec8da536ede5749f3efe34cb9dc5c.jpg

Link to comment
Share on other sites

Hi   The usual method of removing broken stubs in crowns  is to soak them in Alum (warm) which dissolves steel and leaves the brass intact, from your picture it looks as if the stem is screwed into a steel shaft fitted to the actual crown, so I dont think that method would work,  One could use a screw extractor  which cuts left handed into the screw therfore turning the screw out , the problem being there maybe thread lock or lock tite on the stem .  Heating the stem core will destroy any gaskets in the crown.  Best bet is a new stem and crown        

  • Like 1
Link to comment
Share on other sites

usually it's best if you can dissolve it out but?

I don't suppose you give us a picture of what the crown and stem are supposed to look like?

when I started to do the answer I stopped it but because I agreed it look like dissolving would be bad except? Look at the picture carefully we seem to be missing the square? We still have the rest of the stem there I think so that should unscrew. This is where having a picture of the crown and stem separate would be helpful. But otherwise I think you can just unscrew that part that sticking out.

Otherwise there is another way just not on this crown. On a lot of these the brass tube extend considerably out away from the crown. If you're really careful with a watchmaker's lathe you can trim the tube down just a little bit then grab what's left of the stem sticking out and unscrew it usually with a helping of penetrating oil helps.

  • Like 1
Link to comment
Share on other sites

Its difficult to say but looking at your pics there might be just enough of the stem left for it to be twisted out with fine pliers or a pin vice. I don't think the Alum trick will work. If it was me and it was not possible to twist out I would file level and drill with a fine drill and then force a larger drill into the hole created and twist out. You might have to add heat because some stems are fitted with loctite. 

Link to comment
Share on other sites

Thanks all for the suggestions. I think the bit that sticks out is actually part of the crown. I have heated it with the tip of a soldering iron and soaked it in acetone, there is not much to get a purchase on. When the new crown and stem arrive I can compare them, I'll post a picture of the new parts. A new crown was only 4 quid to be honest, so not really worth the faff of getting the broken bit out I suppose, but it would still be satisfying. I think fine drills would be the way to go.

Edited by Davey57
Link to comment
Share on other sites

I personally use winegar bath for broken stems in crowns. It takes at least 2-4 days and transforms to black mud. You can check the process works when its bubbling around the stem while waiting to dissolve. Heating up the winegar accelerates the process. 

Edited by Khan
Link to comment
Share on other sites

usually it's best if you can dissolve it out but?
I don't suppose you give us a picture of what the crown and stem are supposed to look like?
when I started to do the answer I stopped it but because I agreed it look like dissolving would be bad except? Look at the picture carefully we seem to be missing the square? We still have the rest of the stem there I think so that should unscrew. This is where having a picture of the crown and stem separate would be helpful. But otherwise I think you can just unscrew that part that sticking out.
Otherwise there is another way just not on this crown. On a lot of these the brass tube extend considerably out away from the crown. If you're really careful with a watchmaker's lathe you can trim the tube down just a little bit then grab what's left of the stem sticking out and unscrew it usually with a helping of penetrating oil helps.

Now that is a good plan. Or drill it out with a very fine bit

Sent from my GT-N5110 using Tapatalk

Link to comment
Share on other sites

Just to satisfy your curiosity, here’s a picture of the new crown.  The one I showed has snapped off flush. Going to try the vinegar on the old one, cheaper than buying a lathe:lol:

Thanks again for all the replies.56EDEF9E-939A-4BD7-8AAC-539F58A25187.thumb.jpeg.09fe9cef5709b5bfc74ea92cf9255dcb.jpeg

Link to comment
Share on other sites

  • 1 month later...

Hello everyone,

Due to some clumsiness, I've broken two stems off in two different Seiko crowns. I've performed a search of the site, and the best methods to salvage the crown seem to be either dissolving the stuck portion of the stem in the crown or using a screw extractor.

Someone please correct me if I'm wrong, but I feel like the acid methodology only works where the material one is intending to dissolve is different from the material one is intending to save? These are Seiko stainless steel crowns I'm trying to save, and I don't know what the material the broken stem is made of. Even if the acid method were to work, I'd need to remove the rubber gaskets from the crown in advance. This feels quite daunting to me. The attractive part of this methodology is its price: Esslinger.com sells Bergeon Vissin Liquid For Extracting Broken Watch Screws Bergeon 4503 for $17.95.

I'm more inclined to try a screw extractor. This method is pricier, but appears to me to be safer for the crown. I'm eyeing the Horofix Aluminum Screwdriver Screw Extractor at $59.95, as the Bergeon tool is significantly more expensive. I believe the 0.40mm blade provided with the Horofix kit will do the trick.

The easy and cheap way to remedy my problem is to (a) stop stupidly breaking stems off in crowns; and (b) take advantage of the readily available supply of Seiko crowns and stems on the market. The problem here is shipping time, with ~30 day waits for a part.

I'd appreciate any advice or insights here. I know that the easy and correct method here is probably just buying a new crown and stem, but I'd like to improve my skills and salvage the two crowns I've broken stems off inside.

Cheers,

Dan

Link to comment
Share on other sites

Hi Dan,

just a few weeks ago, I was faced with exactly the same problem: broken stem for a Seiko 7S36-03J0 case (a Seiko 5 watch).
I also had to get rid of the broken off part sitting in the crown.

For me, the alum procedure worked out perfectly: mix alum-powder in water, keep warm, drop the crown in the liquid and see the stem dissolve...
The process took a few days but worked out perfectly without doing any harm to the crown.

Upfront, I asked myself the same question about the different materials you mentioned, but decided just to give it a try (it‘s not an omega-crown...)

Cost: around 4 bucks for the alum-powder and a bit of patience.

I agree, still to be managed is the task of removing the o-ring from the stem and putting it back on afterwards.

I‘m just a hobbyist, so the pros around here might give more details or additional information.

Hope this might help a little bit.

KR
Thorsten

  • Like 1
Link to comment
Share on other sites

Wonderful, thank you for the tips Thoast and Nucejoe. I'm feeling much better about the alum treatment if I can readily slip a new rubber gasket on the crown.

Cheers,

Dan

Link to comment
Share on other sites




  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • Yes I have that in my watch list a JUF if cheap enough I will have a go , if nothing else it will be good for spares
    • Less give a damn- more **BLEEP** it! …nice that it is keeping time I’ve done a couple of these (one with your assistance) and there’s a third that needs work on the tension between what drives the hands and the barrel. Did you have any issue with that? …and I saw Ranfft make a small comment in a thread re: pin pallets- a couple drops of Tillwich blu, let it run down the pins. It is good for 20 degrees of amplitude… I’m using this oil as a cheat code on my unmotivated Venus chrono…
    • This is a very sad day for the industry.. For most of us being amateurs the cost of replacing parts for ETA,s etc will be beyond affordability for the customers.   see full statement below   We have now received the decision from Judge Michael Green on whether or not the High Court has jurisdiction to hear our claim against Swatch, and sadly it is not the decision we had hoped for.   As we have pointed out in previous news items (see below),the rules that Judge Green had to apply strictly prevented him from examining in any way how the Swiss Court arrived at its verdict, even if it is blatantly obvious that the verdict is wrong.   As Swatch’s lawyer was summing up in the last few minutes oft he hearing, the Judge twice pinned him asking if it was alright if, as a result of the Swiss verdict, consumers had to pay 50% more for their watch repairs. After some stumbling, their lawyer’s reply was “Yes”, so  I am quite sure that Judge Green left his court fully aware that the Swiss verdict does not reflect the norms of British Competition Law. However, the rules simply do not allow him to take that simple fact into account.   Judge Green noted that our two arguments relating firstly to British Competition Law now being different from that of the EU, and secondly to the contention that the legality of the Authorised Service Networks has not been tested, had both been mentioned in the Swiss verdict. Because they had been mentioned, he felt that to allow us to argue them again would constitute re examining the Swiss case, and could not be allowed.   As to our claim that we were denied our right to be heard because our evidence was not considered, our lawyers had argued that the evidence we provided could not have been looked at because had the Swiss Court done so, it could not have reached the conclusion that it did. In his verdict, Judge Green highlighted general statements in the Swiss verdict that evidence had been looked at, and acknowledged the arguments we made to him, but again he considered that this was re-examining the Swiss verdict, and could not be permitted.   Our case has attracted considerable interest within the Legal community, and within minutes of the decision being made public we were approached for comment by one of the largest subscription news services, Global Competition Review. They asked us two very pertinent questions, and I reproduce them for you below along with our responses, as they neatly summarise the consequences arising from our case.   What are the key takeaways?   Enormous damage has been done to the fundamentals of UK and European Competition Law by the Swiss courts. It has always been the case that the effect on consumers and competition has to be considered in any decision making, but we now have a ruling that states even monopolists can remove wholesale markets from the supply chain without any consumer benefit based justification. Those entities looking to subvert Competition Law and exploit consumers for their own benefit will be looking at this very carefully.   Has the court made the wrong decision? If so, will you appeal?   The issue lies not with the High Court, but rather with cross border jurisdiction treaties that have no requirement in them for foreign jurisdictions applying UK law to take account of the Ratio Legis [a legal term for the fundamental reasoning why the law was written] of that law, and have no remedy within them for UK Courts to overcome decisions that clearly do not.    After eight years of work, and a very considerable sum in legal costs, I can not begin to tell you how disappointed I am at this outcome. For the time being, there is no further route through the British Courts that Cousins can follow. However, I promised that we would fight to the end, and that promise stands.   The UK is no longer part of the Lugano Convention, whose rules Judge Green has applied, and as yet nothing permanent has replaced it. The political tide turned against repair prevention by restricting supply of spare parts some time ago, and our efforts on behalf of the Watch Repair industry have resulted in high level contacts within several Government Departments. You can be sure that we will keep working to overcome this unjust situation that we now all find ourselves in.    I will keep you advised.   Kind regards   Anthony
    • Dell fancy a challenge🤣   https://www.ebay.co.uk/itm/285785684626?itmmeta=01HT29WVJY21Q94C73GYHGBTFX&hash=item428a277a92:g:15YAAOSwNRVmBAUz&itmprp=enc%3AAQAJAAAA0DIe4QLQBW66rSyIMiyBuk8GY%2B86pQ%2BQnxGbcNq7egAGe5DIs9YMmiWJIbZtMSxwNJIiJxuojbq523IeUSBQ6pJEIQ0tfz2ChrBR03BksmKINyklg1IK4GAfAcYY9Hta9wVeSZSZN7ZCNAfZTgKs9c4%2BUIUZ3Qjc3QjUXDn2uPRo1FiYOEewMG5A26EXb%2BclBgrqtbOmM6P3bea%2F8ZImOAXNI1HtbmtMk84pIGoM6ISwaM1PKFuADtTFMccS5e3ZjndCbXYXHrW3CecsV0edw3M%3D|tkp%3ABk9SR8q588nQYw Darwin’s theory of evolution has not been proven to be absolutely.  😀 
    • A already know the size movement I have the problem is the dial a had purchased has a dimension 20.6mm wide a want to find a watch case that going to fit the dial perfectly 
×
×
  • Create New...