Tavannes Restoration Begins

[John Hinkey]

And so it starts.

I decided to take a slow measured crack at bringing back to life my Grandfather's ~1920 Tavannes watch given to him by his high school for being a coach or something like that. It has a broken balance it appears, so I got two donor watches for parts and practice, which I just received the last of tonight. Been collecting knowledge from you all, tools, configuring the camera/video gear that I have on hand, purchasing lubricants, etc.

And now I will begin.

Here's some pics of the three watches - the two donor/parts watches are at the top and the to-be-restored watch is at the bottom. The decagon-cased watch actually runs pretty well - it has a weak main spring and it loses a few minutes each day, but other than that it runs (the Ebay guy who sold it said it ran occasionally, so I'm pleasantly surprised that it runs this well).
The nickel-cased watch has been abused as the stem is broken/missing, the balance is totally shot, balance spring missing, the clock spring is a hand-made spring/wire and the pallet fork no longer has a fork on the end - it's completely missing! I does have a very similar dial that I may have to use instead of the original. I was advertised for parts and that it sure is. It looks like it's been taken apart a few times.



I managed to gently let the main spring down on the nickel-cased watch despite it not having any stem to grab onto (I just put my thumb on the crown & ratchet wheels to let them turn slowly). I will now take it apart/clean/reassemble this parts/practice movement to learn these processes before I take apart the decagon-case Tavannes to get it back to full working order and accuracy. Only then will I tackle the heirloom watch, which needs a dial restoration, new balance, etc., etc.

So stay tuned for more updates as things progress.

 

[John Hinkey]

And so it really has started.
Started with disassembling the nickel-cased spare parts watch/movement.


and now it's all apart except for the barrel which I'll do tonight or tomorrow:


This was a parts watch off of ebay and boy was it:
Broken balance staff + missing balance spring+ pallet fork had the fork broken off


and the last brass wheel (fourth wheel) that connects to the escape wheel was all bent out of shape:


Overall it went fairly smoothly, though it did take me a bit to figure out how to get the cannon pinion separated from the center shaft without a cannon pinion tool - seem Tavannes machined in some features that allowed a strategically placed small screwdriver to gently pry it off.

It was pretty dirty, especially the pallet jewels, so I will practice cleaning everything as well as re-assembling (and oiling) the parts as they are. Since the pallet fork and balance are broken I won't be able to see how it runs, but I can at least get power to the pallet fork and see if it snaps back and forth.

This movement is for practice and spare parts - primarily the dial which is in very good shape and extremely similar to the heirloom watch dial which is in very bad shape.

More later -

John

 

[John Hinkey]

Perhaps this thread should be moved to the Watch Repair forum? Or since it's an European pocket watch it stays here.

 

[John Hinkey]

Last thing for disassembly was to remove the mainspring:

I assume this is "set"? since it's still in a spiral or is this normal for a 1920 vintage Tavannes pocket watch?
I assume I'll need a new mainspring for the family heirloom watch - so how does one go about finding a suitable replacement after taking measurements of the barrel and the spring?

Thanks -

John

 

[gmorse]

Hi John,

I assume this is "set"? since it's still in a spiral or is this normal for a 1920 vintage Tavannes pocket watch?
I assume I'll need a new mainspring for the family heirloom watch - so how does one go about finding a suitable replacement after taking measurements of the barrel and the spring?

Yes, this is set; a blue steel spring will always be this general shape, but a mainspring should expand to at least three times the barrel diameter when out of the barrel. If you can't find a specific mainspring for this model, (and any 'NOS' springs you come across will be blue steel and will have been in their constraints for many decades now and prone to fracture, so are to be avoided), then go to David Boettcher's excellent website, where you'll find useful information and also some calculators. With this information you can go to one of the big materials houses and search through their springs.

Next question, do you have a mainspring winder?

Regards,

Graham

 

[John Hinkey]

Thanks Graham!

This looks to be just about 2.5x the barrel diameter - so it's marginal at best then.

No, I do not have a main spring winder.

 

[John Hinkey]

Hi John,


Yes, this is set; a blue steel spring will always be this general shape, but a mainspring should expand to at least three times the barrel diameter when out of the barrel. If you can't find a specific mainspring for this model, (and any 'NOS' springs you come across will be blue steel and will have been in their constraints for many decades now and prone to fracture, so are to be avoided), then go to David Boettcher's excellent website, where you'll find useful information and also some calculators. With this information you can go to one of the big materials houses and search through their springs.

Next question, do you have a mainspring winder?

Regards,

Graham

So here are my spring dimensions:
1.67mm width
0.21mm thick
Barrel dimensions:
15.54mm ID
2.12mm deep w/o the cap installed, which will take off about .4mm
arbor OD = 4.65mm

So various ways of calculating the length are from 16.2 to 18.5 inches

On Otto Frei it seems I have two 1.7mm width options:
Metric Width: 1.7 mm, Metric Strength: 0.21 mm, Length in Inches: 15.5
Dennison Width: 8, Dennison Strength: 3
and
Metric Width: 1.7 mm, Metric Strength: 0.2 mm, Length in Inches: 16.25
Dennison Width: 8, Dennison Strength: 3.5

I assume it would be better to get the 0.21mm/15.5 inch length vs. the 0.2mm/16.25 inch length.

At Cousin.UK I could only find:
1.70 x .20 x 460 x 15.5 Non-Automatic
which is 18.1 inches long, but only 0.20mm instead of the 0.21mm the spring I have on hand is. 15.5 is the barrel diameter which is close.

Thoughts?

- John

 

[gmorse]

Hi John,

David's first calculator gives the following for your existing dimensions:
Results: spring length = 411, turns = 6.5, barrel/arbor = 3.3, barrel/spring = 74, arbor/spring = 22.

With a spring thickness of 0.20, it gives:
Results: spring length = 432, turns = 6.9, barrel/arbor = 3.3, barrel/spring = 78, arbor/spring = 23.

Using the 'Reverse Engineering' calculator, (just the barrel ID), the suggestion is:
Results: spring thickness = 0.192, length = 481, turns = 6.3, fill = 55%.

I wouldn't worry about the odd few hundredths of a millimetre on most of the dimensions, but as you can see, the thickness does have an effect, since the strength is proportional to the cube of the thickness. You'll notice that the calculators take no account of spring height because the strength is directly proportional to it, and the thickness has a far greater influence. Although the strength is inversely proportional to the length, as long as the ratio of 'free space' areas in the barrel is approximately correct, the length is less important.

If you're really certain about the internal height of the barrel, (you must measure this accurately to be sure, the lid must close properly and the spring mustn't bind), there are several 1.8 mm, 1.9 mm and 2.0 mm high, 0.19 mm and 0.20 mm thick springs available from Cousins. There's quite a lot of choice, many of which would be quite satisfactory. The present spring may be the result of an earlier compromise on the part of the repairer, so it's always worth checking the barrel dimensions very carefully.

However, we have to work with what's available, and since the present spring may not be original anyway, the watch should run quite happily on a 1.90 x .20 x 440 x 14 Non-Automatic (GR5658) or a 2.00 x .20 x 420 x 16 Non-Automatic (GR5900). These lengths are within the acceptable range and should give adequate running duration, allowing you to use them as they are without having to reduce the lengths. As you don't have a spring winder, I'd go for the smaller barrel ID so that you can pop the spring straight in from its constraint ring. Just make sure its the right way round first!

Regards,

Graham

 

[John Hinkey]

Thanks.

I used a digital caliper and I've got lots of machining experience, so my 1.67mm and 0.21mm dimensions are quite accurate as well as the barrel dimensions. I would not go above a 1.7mm spring width based on my measurements, but I'll check my barrel measurements again to be sure.

- John

 

[gmorse]

Hi John,

I was thinking of the barrel dimensions rather than those of the existing spring. The thickness of a barrel base isn't easy to measure with a vernier caliper.

Regards,

Graham

 

[John Hinkey]

Hi John,

I was thinking of the barrel dimensions rather than those of the existing spring. The thickness of a barrel base isn't easy to measure with a vernier caliper.

Regards,

Graham

I have other precision measuring tools that I will use and get back some measurements later today after I get done what my day job requires!

- John

 

[John Hinkey]

I have other precision measuring tools that I will use and get back some measurements later today after I get done what my day job requires!

- John

Based on some additional careful measurements and modeling in CAD:

When the top snaps in it really is slightly recessed around the edges as the CAD indicates.

From the above model I get 1.78mm distance internally between the snap in plate and the main body of the barrel. That's likely +/-0.02 at best and likely +/-0.05 with measurement error and uncertainty stack-up.

So a 1.8mm width main spring might just fit, but 1.7mm width would be safe. 1.9mm no way.

Since this is a practice watch I would get a 1.7mm and a 1.8mm and see which one will fit. I can use this barrel on the heirloom watch and it will be interesting to see the barrel and spring in the heirloom and working parts watches as well when I take those apart.

So my earlier 1.7mm choice should be OK and I will find a 1.8mm spring as well and order both. I'll recap my selections before I place the order.

- John

 

[gmorse]

Hi John,

Excellent, so now you're sure of the barrel dimensions and in a good position to order a spring. If you go for one designated for a 15 mm barrel, around 440 mm long, it should just pop in from the constraint ring without worrying about a winder. These springs are supposed to be ready lubricated.

Regards

Graham

 

[John Hinkey]

Hi John,

Excellent, so now you're sure of the barrel dimensions and in a good position to order a spring. If you go for one designated for a 15 mm barrel, around 440 mm long, it should just pop in from the constraint ring without worrying about a winder. These springs are supposed to be ready lubricated.

Regards

Graham

Awesome. Some fun for this afternoon or tonight!
In the mean time I will get all the parts cleaned and ready for re-assembly
- J

 

[John Hinkey]

Late last night I ordered:

From CousinsUK:
1.80mm x .195mm x 460mm x 15mm Non-Automatic (GR5410)
1.70mm x 0.20mm x 440mm x 15mm Non-Automatic (GR5107)

and from Ofrei:
83T
Metric Width: 1.7 mm, Metric Strength: 0.21 mm, Length in Inches: 15.5
Dennison Width: 8, Dennison Strength: 3

we'll see if the 1.8mm will fit and we'll see what springs are in the other two watches (the heirloom and the working parts watch).
Should get these next week or so.

Thanks for your help!

 

[John Hinkey]

Update.
Spent time cleaning everything in lighter fluid (Naptha) and doing a full inspection of all the jewels, etc.
Boy, just like the poor pallet fork the jewels are in bad shape. Most are chipped (though none completely cracked). A few look OK.


etc.
It's just a practice movement and I'll put it all back together even though it won't run just to practice.

Things I've learned so far just taking it apart and cleaning it:

• Those screws are tiny and it takes practice to pick them up and let them go when you want to w/o loosing them. So far none have flown away
  • I've learned it's better to squeeze with the tweezers too softly than too hard)
• Having high magnification (in my case a 250x USB microscope) sure is handy to see what's going on
• Those years and years of gunk don't always just melt away with a quick Naptha bath. Some scrubbing is required. Though an overnight in Naptha does a good job.
• A cleaning brush (stiff paint brush) of different sizes and shapes come in handy
• IPA for a final rinse highly recommended
• Pallet stones don't like being cleaned with any kind of force (I knocked one loose). It and the balance were not put in IPA.
• Finding a workable replacement main spring is not necessarily straight forward.

So I plan on putting it back together even though it won't run and practice oiling it too.

After that we'll tackle the running Tavannes watch. We'll put it on the timegrapher (I built my own) and record how well it works, then do the full teardown, cleaning, re-assembly, and oiling to see how well I did. Then if I pass that test we'll do the actual heirloom Tavannes which definitely has some restoration challenges (broken balance, corroded dial, missing crystal, etc.).

Three of my 6 inherited watches are coming back from the pro watch restoration shop this weekend and I'll take images of those.

- John

 

[gmorse]

Hi John,

So I plan on putting it back together even though it won't run and practice oiling it too.

All good stuff, lessons learnt this way usually stick! Sharpened pegwood, (cocktail sticks will do at a pinch), is used to clean out the pivot holes, (both jewelled and plain). Repeat until the point comes out clean. A cheap toothbrush is good for more stubborn deposits in other areas.

If you're cleaning with naphtha, there will be no water involved, so why rinse with IPA? A final rinse with clean naphtha will do very well.

As for lubrication, you may find this BHI document useful.

Regards,

Graham

View attachment 692968

 

[John Hinkey]

Hi John,


All good stuff, lessons learnt this way usually stick! Sharpened pegwood, (cocktail sticks will do at a pinch), is used to clean out the pivot holes, (both jewelled and plain). Repeat until the point comes out clean. A cheap toothbrush is good for more stubborn deposits in other areas.

If you're cleaning with naphtha, there will be no water involved, so why rinse with IPA? A final rinse with clean naphtha will do very well.

As for lubrication, you may find this BHI document useful.

Regards,

Graham

View attachment 692968

Thanks Graham - I've been through the oiling document before.
I have and have been using sharpened pegwood sticks to great effect, though I need to learn to sharpen the tips better to get the point down into the jewels better.
IPA was just a final rinse to remove any stuff that may have been left over from the Naptha. Plus it feels to me that after the 2nd (separate container) Naptha rinse the parts still have a petroleum "feel" to them though you can't see anything. Can't hurt! I'm a 99.5% IPA fan based on other micro-type work that I've done before.

Once question that I have is how to remove the apparent staining/discoloration of the movement components (like this bridge below), like can be seen here in the lower part of the image:

this isn't rust and doesn't seem to come off even after an overnight in Naptha and some heavy scrubbing with a small brush.

Thanks -

John

 

[gmorse]

Hi John,

Once question that I have is how to remove the apparent staining/discoloration of the movement components (like this bridge below), like can be seen here in the lower part of the image:

This is where plain solvents just aren't good enough, the chemicals in that staining aren't soluble in naphtha; all the commercial watch cleaners, whether solvent or water based, have some constituents that are essentially soaps, wetting agents and brighteners, (some include ammonia as a brightener as well, but that's a matter of choice). They work on stains and some corrosion products, and the rinses associated with the solvent types are the same base as the cleaners, minus these extra items in the recipes, so that they remove traces of the cleaner effectively.

For the small usage of cleaners and rinses needed by collectors and hobbyists, the water-based concentrates have their attractions economically, and if you're using IPA as a rinse that should dispose of any remaining water. Using two separate rinses following the cleaner is a good practice whatever type of cleaner you choose.

Regards,

Graham

 

[John Hinkey]

Hi John,


This is where plain solvents just aren't good enough, the chemicals in that staining aren't soluble in naphtha; all the commercial watch cleaners, whether solvent or water based, have some constituents that are essentially soaps, wetting agents and brighteners, (some include ammonia as a brightener as well, but that's a matter of choice). They work on stains and some corrosion products, and the rinses associated with the solvent types are the same base as the cleaners, minus these extra items in the recipes, so that they remove traces of the cleaner effectively.

For the small usage of cleaners and rinses needed by collectors and hobbyists, the water-based concentrates have their attractions economically, and if you're using IPA as a rinse that should dispose of any remaining water. Using two separate rinses following the cleaner is a good practice whatever type of cleaner you choose.

Regards,

Graham

Graham -
Can you recommend a cleaning solution that will de-stain some of these parts that naptha won't clean up?
I see lots of Zenith product on Esslinger, but it's not clear which would be best for manual part cleaning and low usage of an amateur such as myself:

a gallon will last me the rest of my life and it would be nice to use just one cleaning fluid and rinse with water/alcohol/etc.
Thanks -

John

 

[gmorse]

Hi John,

I'm afraid I can't offer you an opinion on the Zenith cleaners, simply because I've never used them; I'm not sure they're even available in the UK. I've always used solvent based cleaners, currently L&R, (the 566 and Ultrasonic Rinse). Although the rinses don't deteriorate over time, the cleaners often do, and you may not finish a gallon before it's unusable.

I think one of the concentrated water based cleaners such as Elma 'Red' would suit your low usage better, as they tend to be available in smaller containers at a lower cost, (from some sellers repackaged as small as 100ml).

Regards,

Graham

 

[John Hinkey]

I just bought some L&R 111 based on some other input that I've gotten. It's a whole gallon worth and I will likely never use it all, but in the end it wasn't that much more expensive than a 100mL bottle of other stuff after tax and shipping. It contains brighteners and other cleaning agents which is what I wanted. After having 3 of my 6 watches stolen, I will be working on at least 3 watches myself, all of which need some significant cleaning of the components.
The Tavannes watch restoration has taken a little pause while I've been dealing with the stolen watch issue (what a time sink!) as well as starting to work on my 1883 Longines (covered in another thread).
Thanks -
John

 

[John Hinkey]

Well, to resurrect this thread I've started the restoration of the actual heirloom watch.
As you can see it's all apart:


The dial is so, so dirty. The mainspring is totally set. And one of the pivots of the balance is kaput.
Also, it seems that this watch has been worked on a lot as there are all sorts of marks and signs of repair internally.

The balance spring looks good, just the staff is broken, so a new staff is in the works.
The jewels so far as I can see are all OK, but we'll really see what's going on after they are cleaned.

So this one will be some work - I may find another donor movement to get the staff as my 1st donor movement also has a broken staff. The 2nd donor movement seems too nice (it's a working watch) to yank the balance out of.

More soon. The adventure really begins.

- John

 

[John Hinkey]

OK, first repair questions for this particular watch movement:

• What advice do you have for that dial? Do I try some water and light cleaning, put it in denture cleaner, throw it away and use one of my similar dials from a donor watch? Certainly using alcohol or something strong will likely ruin it (dissolve the printed parts). The numbers are gold-plated and it's clear that the original dial was much lighter in color (likely white).
• Advice for getting a new balance staff - the balance spring, impulse jewel, etc. of the current one look ok, just the pivot is broken. Just one of my donor watches has an apparently identical balance, but is a fantastic working movement that I'd hate to cannibalize just for the balance staff

Thanks!

- John

 

[gmorse]

Hi John,

What advice do you have for that dial? Do I try some water and light cleaning, put it in denture cleaner, throw it away and use one of my similar dials from a donor watch? Certainly using alcohol or something strong will likely ruin it (dissolve the printed parts). The numbers are gold-plated and it's clear that the original dial was much lighter in color (likely white).

It's hard to tell exactly what the finish is on the dial. It seems to be painted, judging by the apparent blisters, (which will be impossible to remove without leaving holes). A weak solution of washing-up liquid in tepid water applied sparingly with cotton buds in a rolling motion is where I'd start, taking extra care with the printed signature and numbers. Denture cleaner is good for enamel dials but not for any other type.

Advice for getting a new balance staff - the balance spring, impulse jewel, etc. of the current one look ok, just the pivot is broken. Just one of my donor watches has an apparently identical balance, but is a fantastic working movement that I'd hate to cannibalize just for the balance staff

If you can't find the correct part from one of the materials houses, you may end up having to get one made. It's not unusual with older watches.

Regards,

Graham

 

[John Hinkey]

Hi John,


It's hard to tell exactly what the finish is on the dial. It seems to be painted, judging by the apparent blisters, (which will be impossible to remove without leaving holes). A weak solution of washing-up liquid in tepid water applied sparingly with cotton buds in a rolling motion is where I'd start, taking extra care with the printed signature and numbers. Denture cleaner is good for enamel dials but not for any other type.



If you can't find the correct part from one of the materials houses, you may end up having to get one made. It's not unusual with older watches.

Regards,

Graham

Unfortunately I can't even tell you what movement number this Tavannes movement is to try to figure out what the correct balance staff is.
Later Tavannes movements have this stamped on the main plate, but not this vintage (1920's).

As far as the dial, I do have a very similar one from one of my (broken staff) donor watches that looks very nice and will fit the original movement:

I'll give the original some water+soap light cleaning to see what I can do, but it looks like the one on the left will likely be used.

- John

 

[John Hinkey]

Ah, unfortunately anything that takes any of the grime off the original (right side) dial is taking the printing off. So we will leave it and use the one on the left as it fits both the case and the movement.

 

[John Hinkey]

Next question is philosophical -
The original 15 jewel movement is pretty dirty, has a broken balance and has had a hard life it appears (lots of tool marks from previous watchmakers, etc.). I have an identical later serial number donor movement that already runs well w/o doing anything to it (I'd still fully restore it anyways) , it fits in the original case and will work with the non-original dial on the left above. I also have my eye on two possible replacement movements currently on ebay that are even newer in serial number, but have 17 jewels and are apparently working/running.

So, since the original dial is not salvageable and the original movement needs lots of TLC besides just a new balance, do you guys usually have any qualms about just completely replacing a watch movement with one that's nearly identical (also a 15 jewel) or replacing it with a movement that's a bit nicer (17 jewel) while keeping the externals of the watch effectively the same?

The engraved case is 14K gold filled and does not have a serial number on it so no one would know except me that I've swapped out the movement.
The dial is nearly identical to the original. Really it's the engraved case that makes this a family heirloom, though at the beginning of this the intent was to use as much of the original watch parts to get it back running again.

Thoughts?

- John

 

[gmorse]

Hi John,

Your Grandfather knew the watch from the outside, by its case and dial, not by the precise details of its movement, and I think in these particular circumstances you would be justified in bringing it back to life in the way you've described.

Regards,

Graham

 

[BillyHelbender]

Personally if it was my grandfathers watch I'd replace as little as possible of the original unless absolutely necessary. I'm guessing it depends on which is more important to you the sentimental value or if the watch looks and works correctly.
Honestly though it's now YOUR watch so there really is no wrong answer.

 

[John Hinkey]

Personally if it was my grandfathers watch I'd replace as little as possible of the original unless absolutely necessary. I'm guessing it depends on which is more important to you the sentimental value or if the watch looks and works correctly.
Honestly though it's now YOUR watch so there really is no wrong answer.

Yeah, I need to do an initial cleaning and fully inspect all the jewels and non-jeweled bearings along with the pallet jewels of the heirloom watch. Part of this decision is how much work it will be to replace/repair stuff vs. movement replacement (which will likely need new mainspring and a full cleaning too . . . with unknown problems of their own).

Thanks for the advice . . .

- John

 

[John Hinkey]

Hi John,

Your Grandfather knew the watch from the outside, by its case and dial, not by the precise details of its movement, and I think in these particular circumstances you would be justified in bringing it back to life in the way you've described.

Regards,

Graham

Yes, it was the case and dial primarily. Kind of like owning your grandfather's '64 Mustang. Replacing the engine with a new/identical or slightly different because the original is worn out, but keeping the paint color, chrome, tires, upholstery, etc. the same is probably OK by him if he were around.

- John

 

[John Hinkey]

Well, well. You take a 1920 PW apart and find strange things.
Here's the main plate with the barrel bridge placed back on it and some arrows pointing to two worn bearing holes and some exposed brass indicating some material had been cut/filed away :

a slightly closer look:


That's areally bad looking bearing hole in the main plate. The other hole is more subtle in its problems.

As I said previously, this movement is in sad shape - now even more so that just the broken balance pivot.

The good news is that the jewels look in pretty good shape - no obvious cracks, but may have some small chipping in the pivot holes.
The watch is fairly clean overall, except for the mainspring barrel whish has some gummy residue to clean out.

Looks like this original movement is at the end of it's life, despite clearly being worked on in the past several times (according to the jewelers markings on the case). Still, my grandfather passed away in 1967 - so the watch certainly hasn't been maintained in 55 years (f not longer).

So I will be replacing the movement wholesale with either the one I have in hand or this one that I'll be buying on ebay:

since I can't find a similar age/design 17 jewel movement.

Ah the fun of opening up old non-working movements.

- John

 

[John Hinkey]

So, I actually ended up buying this movement (because the one I really wanted suddenly became sold):


It runs (more on this later) and at least if comes with a dial, hands, and a winding stem which may become useful later.

As talked about above this is the movement that I want to transplant into my Grandfather's open face PW.

So last night I threw it on the timegrapher before I completely disassembled it and found:
~3s/day rate, 300 deg. amplitude, but 9+msec beat error. It actually kept decent time over half a day.
So one could say - why mess with it?
Well, you could tell when you wound it up the winding mechanism felt a tad "gummy", when you let down the mainspring it also felt like it would let down most of the way and then very gradually keep going, and I could see some debris/build-up/gunk on many of the jewels, wheels, etc.
Also, likely this watch still had the original blue steel mainspring.

So apart it came - took me about 2 hours with a good chunk of that dealing with removing the balance spring from the balance cock - the little stud just did not want to come off.

I then proceeded to perform an initial brush/pegwood cleaning in Naptha (lighter fluid) and found:

• Jewels, etc. were not too dirty, whatever was on them was more crusty than gummy, so it cleaned up pretty well
• Had the old steel mainspring that was very set
• Lots of wear and gummy stuff in the winding mechanism
• Lots of wear and gummy stuff in the mainspring barrel
• Wheels and their pivots all looked pretty good
• One jewel looked like it had a crack, but no chipped jewels
• Balance spring looked OK - some stuff on the hairspring, but I have yet to clean it
• Canon pinion and the arbor it goes on looked pretty worn - may replace these using my other Tavannes donor movements
• The un-jeweled hole for the center wheel in the main plate looks a bit worn - but I'll see how this is when the donor canon pinion, etc.
• Escape wheel needs some micro-cleaning to get hard crusty stuff off the teeth
• The pallet and pallet jewels look great
• The impulse jewel looks just fine

So not too bad. I'm going to run everything through L&R111 to see what might be left for more manual cleaning. I'm hoping the Nickel plating and the gold paint on the numbering/lettering cleans up better (couldn't get all the dirt out of the numbering/lettering).

The jewel really needs to be replaced, but we'll deal with that later. The main plate is in great shape - way better than the original movement for sure.

Pics below for those hard core interested in such a movement and the fun stuff you find inside a 100 year old watch:
Remove the balance - spring looks in good shape.

The dial side looks OK so far -


Removing the train wheel bridge to see the lovely wheels:

Some wear is now evident -

First look of the mainspring barrel -

ooh some major wear -



some wear also on the setting works side:


Mainspring barrel now open - a bit gummy stuff in there:

Yep, that old spring is pretty set -

and finally that balance cap jewel is just a bit crusy -


More after an L&R111 cleaning.

- J

 

[John Hinkey]

Well, after a thorough cleaning we have a problem - the screw that holds down the cap jewel retaining plate on the bridge that holds the escape wheel is stripped out - see the the shiny plate here on the lower left of this ebay image:

is stripped:



So that screw hole, which only had a few threads in it anyways is stripped out and the cap jewel capture plate is just loose and easily falls off.

What are my repair options?

• Use a flathead screw of the next size up? But I don't have such screws or the tap.
• Stake around the threaded hole to close it in enough to allow the screw to grab onto something? Seems dicey. Don't have these tools either.
• Put a dap of JB weld in the hole and thread the screw in while it sets up? Boy that would be half-assed.
• Use the equivalent donor jewel escape wheel bridge that does not have a cap jewel - I wonder if it will fit? Do this temporarily while I do the rest of the assembly and get it working again.
• Have someone laser deposit some brass around the hole and have it re-tapped? That would be cool, but I don't know of anyone that can do this.

Really, I'd love to just send it to someone that can repair this and not do it myself. Any suggestions?

Thanks -

John

 

[gmorse]

Hi John,

There are more alternatives to add to those you've already covered, one of which is to fit a conical plug from the underside and drill and tap it to fit the existing screw. However, this also requires tools you don't have. The stresses on this part are minimal, and the least invasive, and hence most easily reversible solution, is probably to use one of the thread locker products that's designed to work with larger clearances; have a look at the Loctite website, they have a huge range of products.

Regards,

Graham

 

[John Hinkey]

Hi John,

There are more alternatives to add to those you've already covered, one of which is to fit a conical plug from the underside and drill and tap it to fit the existing screw. However, this also requires tools you don't have. The stresses on this part are minimal, and the least invasive, and hence most easily reversible solution, is probably to use one of the thread locker products that's designed to work with larger clearances; have a look at the Loctite website, they have a huge range of products.

Regards,

Graham

Thanks Graham - I will also order a 0.5mm x 2mm flat head screw as the existing screw has a terribly worn slot that makes it almost impossible to do anything with.
I'll measure the existing screw first as it might be a different size.

Also, these guys sell a box of screws for pocket watches, but unfortunately they don't list the screw sizes or shapes:

Screw Assortment for Pocket Watches

and other professional jeweler and watchmaker supplies at Cas-Ker Jewelers Supplies

www.jewelerssupplies.com

Also, if one uses something like JB weld, you can coat the screw with oil so the JB weld won't stick and you can rotate the screw back out after the JB weld sets up.

All not terribly optimal.

I will also try to use a donor bridge and escape wheel to see if those will allow me to get the watch up and going - these are easy to change out with the watch fully assembled once we fix this issue.

 

[John Hinkey]

Hi John,

There are more alternatives to add to those you've already covered, one of which is to fit a conical plug from the underside and drill and tap it to fit the existing screw. However, this also requires tools you don't have. The stresses on this part are minimal, and the least invasive, and hence most easily reversible solution, is probably to use one of the thread locker products that's designed to work with larger clearances; have a look at the Loctite website, they have a huge range of products.

Regards,

Graham

Turns out that a M0.6 screw has a tap drill of just about 0.5mm, so since the hole is stripped out for a 0.5mm screw I think I can just screw in a 0.6mm stainless and let it make the threads in the brass. I just have to screw it in once or twice and it doesn't really need to be tight at all. I also found a 0.6mm stainless nut (that would have to be loctited in place to prevent it from falling out) to use a longer 0.6mm screw. If this doesn't work then we'll do the loctite, JB weld, or have somone make a proper fix to the hole that will fit the original 0.5mm screw. I also found longer 0.5mm screws, but I think they will interfere with the pinion on the escape wheel if I use a nut. The original M0.5 screw is only ~1mm long!

 

[John Hinkey]

Actually, another repair option is to fill the stripped out screw hole with JB Weld, file it smooth on both sides, then drill and tap the hole for 0.5mm thread. The cover of the cap jewel will cover any tooling marks.
There are probably other ways of filling in the hole w/o distorting the bridge or damaging the jewel and then drilling and tapping it, but i don't have those capabilities.
0.6mm stainless flat head slotted screws will be here in a couple of days and will be my first try at a decent repair.

 

[BillyHelbender]

I'd try hot glue fill the hole and screw in the screw. If it doesn't work its easily undoable. I know it sounds rigged but it's also not permanent and could be undone if a better way or more skill present themselves later.

 

[John Hinkey]

I'd try hot glue fill the hole and screw in the screw. If it doesn't work its easily undoable. I know it sounds rigged but it's also not permanent and could be undone if a better way or more skill present themselves later.

Graham will not like this idea!

 

[gmorse]

Hi John,

No, he doesn't, but not because it's using a 'non-traditional' method. I use thread lockers and retaining compounds on occasion where they're appropriate; they have the virtue of being reversible and non-invasive, but getting hot glue to enter such a small hole and restricting it to that hole may not be easy. I would draw the line at soft solder in this particular case, because it can be very hard to remove, especially from gilt surfaces.

Regards,

Graham

 

[John Hinkey]

Hi John,

No, he doesn't, but not because it's using a 'non-traditional' method. I use thread lockers and retaining compounds on occasion where they're appropriate; they have the virtue of being reversible and non-invasive, but getting hot glue to enter such a small hole and restricting it to that hole may not be easy. I would draw the line at soft solder in this particular case, because it can be very hard to remove, especially from gilt surfaces.

Regards,

Graham

I'll be trying the 0.6mm screw repair first as if this strips out more of the hole it won't really affect any subsequent repair options. I just need to screw it in once to make sure it will work, then take it out, oil the cap, then re-install and I'm good to go. If I can't/won't want to take it out after initially putting it in I'll just have to oil the jewel+cap from the other side.

Oh such fun!

 

[BillyHelbender]

Crossing fingers for ya!!

 

[John Hinkey]

Still waiting for my 0.6mm screws, so in the mean time I installed the crystal into the bezel. I ordered two sizes from Whites - could not get the larger diameter in at all while the smaller diameter would pop in nicely, but also easily pop out.
So I used the UV glue on the smaller diameter crystal and so far it appears to be robustly clued into the bezel and has survived taking the bezel on and off:


I also shined up the gold-filled case using a silver polishing cloth which took off some stubborn tarnish on the the gold surface near the hing:

the cell phone pics do not do this justice as it looks very nice.

I think while I work out the repair on the 21 jewel replacement movement I will install the replacement dial, hands and 15 Jewel spare movement I have into this case just to make some progress. It's very easy to swap out the movements once I get them working/repaired/fixed up.

- J

 

[John Hinkey]

Well, it turns out you can screw a M0.6 screw into a stripped-out M0.5 threaded hole that's in a piece of brass:

Fixed well enough - it's not going anywhere. I put in the escape wheel and made sure it spun freely and had some tiny bit of end play. It was not a flathead screw like the original, but to the naked eye it looks pretty decent.

Looks like this repair is done. No adhesives of any kind were were used Graham!

Now, feeling pretty good about myself, I figured I'd take 15 minutes to install the mainspring . . . oh the best laid plans . . .

Selected the 1.7mm wide new spring (see way above), greased up the barrel, pressed the spring in and went to install the barrel arbor and found the curl on the end of the spring was too big (by a lot). The arbor was very loose and was not even close to engaging with the hole in the end of the spring.

Ugh.

So, I've seen YouTube videos of people re-bending the end of the mainspring to make the coil smaller while the spring is still in the barrel . . . easier viewed than done. Got it bent to a smaller diameter (yes, with a pair of small needle nose pliers with serrations Graham) installed the arbor and found that I had inadvertently broken off the end. Ruined mainspring.

Pull it out and the spring goes flying - no harm - now I've had that happen to me.

Pull out the 1.8mm wide mainspring that I had also ordered, unwind it from the shipping ring, bend the end to a smaller diameter fairly easily, hand wind it into the barrel and go to put the arbor in and PING off the arbor goes flying across the room. UGH.

Found it inside of a minute due to the dark flooring and bright steel color of the arbor. Phew!

Clean it up and in it goes, and the barrel cover snaps in apparently normally - so for now at least the 1.8mm mainspring is in and I THINK it's not binding (because it might be too wide). Need to re-order the 1.7mm spring in case the 1.8mm doesn't work out.

Phew^2

I think that's enough success and near disasters for the night.

Tomorrow night/this weekend we start putting the whole thing together. Fingers crossed.

- John

 

[gmorse]

Hi John,

All part of life's rich tapestry . . . .

It's possible that gripping the spring with serrated pliers could have induced the failure; only small surface indentations can lead to breakage at this point. Alloy springs, although described as 'unbreakable' in use are in reality very easy to break if you try and bend them too sharply.

Regards,

Graham

 

[svenedin]

I have had exactly the problem you had with your mainspring. Far too often! I have a mainspring winder but if the inner coil is too big the spring won’t hook on the arbor of the winder either. I have broken multiple springs or had “success” only to find that the spring slips after the watch has been used for a while. It’s frustrating. I do wonder whether the answer is to take the hardness off the inner coil and re-harden.

 

[gmorse]

Hi Stephen,

I do wonder whether the answer is to take the hardness off the inner coil and re-harden.

Once you've drawn the temper on a spring and effectively annealed it, it isn't practical to re-harden and re-temper it, you'll never be able to replicate the manufacturer's heat treatment processes. Trying to re-shape the inner coil once the spring is in the barrel is usually unsuccessful; out of the barrel you do have a better chance, so always check the fit of the arbor before doing anything else.

Regards,

Graham

 

[svenedin]

Hi Stephen,


Once you've drawn the temper on a spring and effectively annealed it, it isn't practical to re-harden and re-temper it, you'll never be able to replicate the manufacturer's heat treatment processes. Trying to re-shape the inner coil once the spring is in the barrel is usually unsuccessful; out of the barrel you do have a better chance, so always check the fit of the arbor before doing anything else.

Regards,

Graham

OK. I‘ve never tried to re-size a spring that’s in the barrel already. I did buy the bending pliers you recommended but the radius is rather large. I’ve wrecked tweezers by trying to reshape the inner coil so it really has to be pliers. For me, springs are one of the most difficult and annoying parts of the whole process of servicing a watch (other than Kif springs!). I can see why the modern lazy way is to bin the barrel and drop in a new barrel complete! We don’t have this option….