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Discussion Starter #1
Just like to pick the brains of others who do watch repairs about attaching crowns to the stems. I was just curious as to what method others are using on the threads when installing a new crown or assembling a whole new crown and stem assembly. I have never seen anything specific mentioned in any Seiko assembly or repair manuals. I am currently just using super glue. I have not had any come loose yet. I have also tried just gripping the stem carefully in a pair on needle nose pliers and twisting the stem by hand firmly with nothing on the stem and that has also seem to work also. I think the metal in the crown threads is a bit soft and by giving it a good twist it distorts the threads in the crown thus making it hard for the crown to unwind. I am curious as to what other people do when then need to attach a crown. I'm always looking for new or better ideas.

Michael
 

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I use blue thread lock applied to the thread of the stem. Srew on the crown and then leave to set for an hour or so
 

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Discussion Starter #4
That was the method I was thinking about. I wanted to see if others were thinking the same thing. The Loctite seemed to be the best solution I just wanted to be sure. I'll just have to go grab it out of my tool box in the garage. Thanks for the response.

Michael
 

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After researching this, I chose Loctite 290 (red). Not had any failures yet.

I went with this on the grounds that if I did want to undo the crown/stem in the future, then with this it 'should' be possible.
 

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Discussion Starter #7
I have to wonder what some stems were attached with sometimes when I buy a parts watch and I am breaking it down and labeling the individual parts. I have come across some crowns that seem to be welded on to the stems. I have had good success though removing just about any stuck crown after a good soaking in acetone. Most have come of with a good grip in the needle nose pliers and just the power of my thumb and forefinger.
 

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After researching this, I chose Loctite 290 (red). Not had any failures yet.

I went with this on the grounds that if I did want to undo the crown/stem in the future, then with this it 'should' be possible.
Id be sure to let that cure for a good couple of hours before you put the stem back into the watch. 290 is for pre-assembled fasteners and works by Caterpillar attraction, its also a sealant and will fill pourous surfaces. If it wicks back along the stem into the tube/ movement you could end up with problems.
 

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Id be sure to let that cure for a good couple of hours before you put the stem back into the watch. 290 is for pre-assembled fasteners and works by Caterpillar attraction, its also a sealant and will fill pourous surfaces. If it wicks back along the stem into the tube/ movement you could end up with problems.
Good advice :D

I always let them set for a few hours or longer outside of the watch. Doing this stops me trying them out before set.
 

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I have to wonder what some stems were attached with sometimes when I buy a parts watch and I am breaking it down and labeling the individual parts. I have come across some crowns that seem to be welded on to the stems. I have had good success though removing just about any stuck crown after a good soaking in acetone. Most have come of with a good grip in the needle nose pliers and just the power of my thumb and forefinger.
Heat (eg from a soldering iron) can be your friend. It will soften epoxies and cyanoacrylates. We like CA glues and rarely use loctite red (and never use blue just doesn't hold well enough for most mechanical movements). On simple quartz with low cannon pinion friction, we might just use crystal cement or nothing, at all. Allowing sufficient curing time for whatever you use is a must...CAs that humidity cure, may take awhile...CAs that UV cure, may cure very slowly or not cure at all.

We use the tools in the attached image, along with a pin vise. Your cutters should be hardened and ground for "flush cut"...

Best regards, BG

BTW, what is "...works by Caterpillar attraction"...not familiar with the term...thanks
 

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Never use super glue. Put it away and never bring it near any watch part again.

I use LockTite blue. I agree that some times a good job of hand tightening with the stem held firm by pliers ****could**** hold, why risk it? Just use the LockTite and let it dry overnight before installing in the case due to the stories told of dials being ruined by the off gases.
 

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Discussion Starter #14
Never use super glue. Put it away and never bring it near any watch part again.

I use LockTite blue. I agree that some times a good job of hand tightening with the stem held firm by pliers ****could**** hold, why risk it? Just use the LockTite and let it dry overnight before installing in the case due to the stories told of dials being ruined by the off gases.
There is one trick to using super glue that does away with the off gases produced when it is cured by air. They sell an accelerant for CA glues that freezes and cures the glue instantly rock hard. Still it is always dangerous to have CA glue fumes near any clear acrylic. They can really destroy them pretty fast. I would not blame anyone who would not want it near their watches. It could come back and bite you. I guess in the end it is up to everyone to make their own choice. No one method is ever perfect in every single situation.

Michael
 

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Not knowing any better, I did my first crown a few days ago and just held the stem firmly in pliers and screwed the crown on. It was very tight to screw on, but seems to be sound. Should I take it off and Loctite it? Doug
 

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To hold the stem I usually use a brass jawed sliding pin vise. The brass will not damage the stem. Failing that a nice smooth jawed pin vise will do the trick. You want to avoid raising a bur on the stem shank as this can damage the mainplate. The bur will act like a boring bar and open up the hole in the plate. I use a good quality pair of side cutters to cut the stem and a credit card sized, medium grit diamond hone to flatten and then slightly bevel the end of the thread. A file would work just as well. Avoid deforming the thread as much as possible as you don't want to damage the potentially softer metal of the crown. I use a very small amount of red Loctite which I apply to the thread of the crown to secure it. This prevents it running back down the stem and secures any potential fumes. Using loctites means there is less chance of the crown coming loose. There is nothing worse than a watch coming back because the crown has come unscrewed! Gently warming the stem is usually enough to break the Loctite.
 
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