Jewel screw retention question...

September 30, 2014, 13:18

Serge Barlas

Greetings all!

I’m looking for advice on dealing with a problem I have not run into before. I’m working on a 16 size three finger bridge movement and have discovered that the pillar plate jewel screws that hold the lower balance cap and hole jewel tight to the plate will no longer grip the plate. These screws are as loose as a straw in a milkshake. I would guess that over the years of having been serviced the plate threads have worn down to nothing and the screws won’t thread up properly. The watch will not run as the jewels fall out of the plate when it is placed dial down. What can be done to remedy this situation? I have considered using a drop of blue Loctite but I’m concerned about permanent damage. Any help would be greatly appreciated!

September 30, 2014, 19:23

Lindell V. Riddle

Serge,

Since we are at some three to four times the expected service life of these watches, many of them far more more than that and as time goes by we will have to resort to doing some heretofore unorthodox things to keep them going while still trying to keep the basic appearance as close to "original" as possible.

Many would immediately deplore what you contemplate, but short of re-tapping and going with larger diameter screws, which would be a permanent, irreversible alteration of the movement, your solution of "...a drop of blue Loctite..." would seem to be a reasonable alternative that could be reversed if someone chose to do so in the future. For years I have used Loctite Thread Locker on automative, small engine and various other repairs and see no reason why it would not be worth a try, be sure all traces of oil are removed from the screw hole, try it and see what happens, either it will bridge the gap for you or it will not.

This will sound shocking to some who read this, but I was told the originally intended use of what we now call "Super-Glue" was not as an adhesive, but as a "bridging material" in typewriter repairs, not at all unlike what you are considering.

If you do it the Blue Loctite, use only a tiny drop, you really have nothing to lose.

Let's see what others say about this idea.

Lindell

September 30, 2014, 20:29

Roger J. Nolfe

I worked for SCM (Smith Corona Marchant) repairing portable typewriters & mechanical adding machines around 1968-69 and then went to work for IBM's office products division fixing every typewriter you can imagine. We never used "Super-Glue" for anything so I would be curious to know where Lin got this information. I do concur that a tiny amount of blue loctite on a screw can be a better alternative than other possible options since it is entirely reversible with no damage at all to the original parts.

September 30, 2014, 20:48

Steven Ford

Serge,
I agree with Lindell, I think loctite is a fine last resort, because it is reversible.

Roger,
I,too, worked on typewriters, adding machines, and the like from 1973 to 2000, and two things you never use on them was super glue and WD40.
I wonder where that came from, too.

Steve

October 01, 2014, 09:38

Rafal Woler

I suppose Lin was thinkig about intention of use. Super glue was side effect of looking for someting different. (super glue is used also for wound patching...) Actualy same situation was with wd40 (name refers to 40th sample tested, I dont remember what they were looking for but they end up with wd40....)

Rafal

October 01, 2014, 19:20

Serge Barlas

Gentlemen,

Thank you for your responses they have been very helpful. I'm glad that I was not too far off the mark; Like they say... nothing ventured, nothing gained. The watch will not run as is and if a drop of blue Loctite saves it, it would be worth the effort.