My first attempt refitting and adjusting pallet stones using shellac

[JohnR725]

Yes it would be better if you could leave the jewels where they are and just move them around. Just a reminder the stones are slightly different angle and you don't want to mix them up. Plus of course you don't want to misplace one as that would be a new fork.

[Endeavor]

5 hours ago, JohnR725 said:

Just a reminder the stones are slightly different angle

An important piece of info I didn't know ! Currently both Miyota jewels are floating in the same jar, so it's going to be a kind of 50/50 . The good thing is that the Miyota was a scrap movement ....... I guess that's the reason for trials, valuable lessons are to be learned ! Thank you very much for your input

BTW; I like your wording; "misplace"

Edited August 6, 2022 by Endeavor

[VWatchie]

On 8/6/2022 at 7:32 AM, Endeavor said:

In case of the Omega 861, where the entry-jewel is deemed to sit slightly too deep, instead of stripping the whole fork wouldn't it be wiser to just warm the fork, melt the old-shellac and try to push the jewel in a bit further?

I believe that's what the professionals do. Personally, I like to do one small step at a time for maximum control. Trying to adjust the stones with the shellac in place I worry I might make a mess, but perhaps I'm overly worried. Perhaps the risk of losing a stone and the additional work of removing the old shellac isn't really worth it. Of course, if the old shellac has deteriorated to the point it's starting to fall apart, which it is not in your case, it needs to be replaced anyway.

On 8/6/2022 at 9:22 AM, JohnR725 said:

Just a reminder the stones are slightly different angle and you don't want to mix them up.

 

On 8/6/2022 at 10:08 AM, Endeavor said:

An important piece of info I didn't know ! Currently both Miyota jewels are floating in the same jar, so it's going to be a kind of 50/50

No worries! The difference in angle is absolutely visible. The angle of the impulse surface on the exit stone is quite a bit steeper than that of the entry stone. Have a look at the third and fourth images in the below-linked post. If you place the stones side by side you will clearly see the difference.

 

Edited August 8, 2022 by VWatchie
clarification

[Endeavor]

After circling around and around it, I finally adjusted the pallet-jewels of my 1975 Omega Speedmaster Mark II.

Inspired & guided by this article, and after having had a huge learning curve replacing "Garnet"-jewels for modern (too small, too low) jewels in a 120 years old pocket watch, I decided it was time to tackle the job.

There are many valuable tips in this article and all I like to do is to share a few of my experiences.

Like VWatchie, I also found that Acetone is a very effective way to remove the old shellac, more effective than industrial isopropanol. Acetone is widely available, no need to look further than your wife's nail-polish remover.

In my case the Acetone turned to old shellac in a white transparent substance, which later, while cleaning the fork-slot, caught me out. I simply didn't see it and hence the fork-slot wasn't cleaned properly.

As for applying the shellac; I tried the "pulling strands on peg-wood"-method and the "creating small balls"-method. To me, the "small balls"-method worked the best. If the size of the ball is too big, one can "nibble" it down with some fine tweezers.

As for the ease of adjusting the depth of the jewels, again I came to the same conclusion as VWatchie. For me it worked far better, and far more relaxed to adjust the jewels without the Shellac applied. As VWatchie said, hopefully there is enough friction between the jewel and the fork-slot to keep the jewel in place for testing. When Shellac is applied, one has to melt it, do the adjustment above a hot plate and there is time-pressure. Plus, without the Shellac, it became for me far more easy to see if the jewel had moved or not. Adjusting the jewels became for me far less cumbersome when done without Shellac.

As for melting the Shellac; initially I used a timer, to get an idea of how long it took for my alcohol burner / pallet-fork heater to get to the Shellac melting-temperature. That worked fine one day, not the other. The alcohol-burner I'm using is not producing a consistent heat and when heating 1 minute was fine on the day, it totally melted the Shellac to "water" on the next. The method I'm using now is to place the Shellac ball on the end of the fork-slot and heat the pallet heater above the flame, performing checks on very regular intervals. One sees the Shellac-balls slowly melting and continues until your are happy with the distribution. If the size of the Shellac ball is slightly too big, you stop before it flows out too far. If the ball is slightly too small, you just heat somewhat longer until it flows out far enough.

As for adjusting the jewels; one can use brass tweezers to push the jewels, from the rear, further out of the fork-slot, but I used peg-wood to push the jewels back in. I did some adjustment testing on junk pallet-forks and when using steel tweezers, the chances that you chip the impulse-plane or the back of the jewel, are very high. With steel-tweezers I had a 100% chip-score with the jewels of both test forks.

One very important "adjustment"-lesson I've learned from @nickelsilver; if you move one jewel, it affects the other: https://www.watchrepairtalk.com/topic/23176-1975-omega-861-amplitude-after-24hrs/#comment-196690 .

It surely does !!

Many thanks to VWatchie for penning this thread and thanks to @nickelsilver and @JohnR725

 

 

 

 

Edited January 10, 2023 by Endeavor

[VWatchie]

Congrats @Endeavor and thanks for sharing experiences made, much appreciated 

Now, it's going to be truly interesting to hear what this manoeuvre did for the amplitude!?

Edited January 10, 2023 by VWatchie

[Endeavor]

Well, sadly that was not the only problem. The Omega 861 has a common problem, the wear around the main-spring barrel, as @nickelsilver mentioned here; https://www.watchrepairtalk.com/topic/23176-1975-omega-861-amplitude-after-24hrs/#comment-196628

Sure enough, look at the wear marks inside the barrel bridge and top of the ratchet wheel ..... sigh

It seems however, that the arbor / barrel-play takes a big part of the blame ..... not that difficult to correct.

The arbor / barrel-bridge, if required, is another challenge (I don't have the equipment for the "bushing-trick", so perhaps to ream out and inserting a jewel?)

 

 

Edited January 10, 2023 by Endeavor

[JohnFrum]

Here copper circuit stripboard and a soldering iron are used. 

 

[nickelsilver]

It's normal to see some wear marks where the ratchet wheel contacts the bridge. As it is just floating there it does make contact- I put a little grease there but it's often dry. You'll need to get a good look at the barrel pivot hole in the bridge and plate, look from the inside with some backlight, the pivot usually doesn't make it all the way through, so it can look round and nice from the outside, but egg shaped from the inside.

[JohnR725]

4 hours ago, nickelsilver said:

It's normal to see some wear marks where the ratchet wheel contacts the bridge. As it is just floating there it does make contact- I put a little grease there but it's often dry.

I think technically it's supposed to float above the main plate but I would agree typically you'll see wear it has touched. Then exactly what you're doing I will put grease anyplace I see that parts are wearing. I also like to check any of the steel components like ratchet wheels to make sure that there is no burrs on the edges of the teeth because sometimes that happens and that's why you'll see the wearing. 

5 hours ago, Endeavor said:

so perhaps to ream out and inserting a jewel?)

Usually they put bushings bushings in as it's hard to get a jewel of the correct size to fit.

[Malocchio]

Ok guys I got myself a heating table and started experimenting with shellac and pallet jewels. I'm really a pallet noob. Here's an unedited video of the shellac melting. First the flakes melted into funny blobs when I had the table set to 100 degrees. I had to up the temp to 150 to get the shellac spreading more. How do you like it? Any comments appreciated. I also post some pics of the side profile.

 

[VWatchie]

On 12/24/2024 at 11:42 PM, Malocchio said:

First the flakes melted into funny blobs when I had the table set to 100 degrees. I had to up the temp to 150 to get the shellac spreading more. How do you like it?

That was a very interesting and useful video. Thank you for sharing! Interesting to see how the shellac contracts into a small bulge. That is, we don't have to be super precise about how we place it on the fork as long as it is in on the lower part as seen in your video.

On 12/24/2024 at 11:42 PM, Malocchio said:

Ok guys I got myself a heating table

Please tell us more. Show us a picture.

[Malocchio]

19 minutes ago, VWatchie said:

That was a very interesting and useful video. Thank you for sharing! Interesting to see how the shellac contracts into a small bulge. That is, we don't have to be super precise about how we place it on the fork as long as it is in on the lower part as seen in your video.

Please tell us more. Show us a picture.

https://a.aliexpress.com/_EyKdzCy

I was originally planning to get one for drying parts but people pointed out that it can be used to melt shellac. That was my second try on the video. First time I put the flakes more like in the middle of the jewel hoping they would melt straight down but they ended up as little shellac balls too stubborn to melt any more despite turning up the heat. Putting the flakes further in the back seemed to help. The fork is on a small steel staking block. I should try some better heat conducting material like copper or aluminum.

[mbwatch]

1 hour ago, Malocchio said:

The fork is on a small steel staking block. I should try some better heat conducting material like copper or aluminum.

Definitely try a different medium. I saw the video and thought "Six minutes!!!" All your energy is going into heating up that big steel staking block. A little sheet of brass with a hole drilled to accept the pallet arbor will make this much faster. The only thing with using a hot plate like this though is that you might need to come up with a solution where one side of the pallet is insulated from the heat. You won't always want to be melting the shellac on both stones at the same time. Old school pallet warmer tools often only conducted heat to one side, and you could turn the fork around to heat the other, or only one half of a split piece of brass would be held over a flame so the other stayed cool - the fork suspended across the 2 halves.

15 minutes ago, mbwatch said:

All your energy is going into heating up that big steel staking block

This is heavily on my mind because I am staying at my in-laws' house this week. All of their cookware is thick cast iron and it takes 15 minutes to bring a saucepan of water to boil.

[Neverenoughwatches]

3 hours ago, VWatchie said:

Interesting to see how the shellac contracts into a small bulge. That is, we don't have to be super precise about how we place it on the fork as long as it is in on the lower part as seen in your video.

Could be some capillary action taking place in the space behind the stone, the mass of the shellac is then held in that vicinity .

[Malocchio]

2 hours ago, mbwatch said:

Definitely try a different medium. I saw the video and thought "Six minutes!!!" All your energy is going into heating up that big steel staking block. A little sheet of brass with a hole drilled to accept the pallet arbor will make this much faster. The only thing with using a hot plate like this though is that you might need to come up with a solution where one side of the pallet is insulated from the heat. You won't always want to be melting the shellac on both stones at the same time. Old school pallet warmer tools often only conducted heat to one side

Some Euro coins are made of 89% copper and 5% aluminum, sounds like a good (and cheap) heat conductor. I've been watching those old pallet warmers on ebay.

[Neverenoughwatches]

2 hours ago, Malocchio said:

Some Euro coins are made of 89% copper and 5% aluminum, sounds like a good (and cheap) heat conductor. I've been watching those old pallet warmers on ebay.

Brass is the most often obvious choice for pallet warmers.

[Malocchio]

2 hours ago, Neverenoughwatches said:

Brass is the most often obvious choice for pallet warmers.

10 cent coin got a new life as a pallet warming platform. A lot more copper than in brass so I bet it'll do the trick.

[GPrideaux]

I'm glad to have found this thread. One of the issues with the c1920 Bulova I'm attempting to repair is missing shellac on one side of the pallet.

A question for those who are experienced with this: should I remove all the shellac from both sides, or will it be sufficient, if I can, to just clean one side up and apply new shellac to just that side? (I suspect the shellac is original to the watch so more than 100 years old.)

There's no hurry on this ... I first need to work out how I can replace a broken rubbed-in escape wheel jewel.

Hmm ... is the guard pin bent or is it just the angle of the photo? Add it to the list of issues for this watch.

[Neverenoughwatches]

40 minutes ago, GPrideaux said:

I'm glad to have found this thread. One of the issues with the c1920 Bulova I'm attempting to repair is missing shellac on one side of the pallet.

A question for those who are experienced with this: should I remove all the shellac from both sides, or will it be sufficient, if I can, to just clean one side up and apply new shellac to just that side? (I suspect the shellac is original to the watch so more than 100 years old.)

There's no hurry on this ... I first need to work out how I can replace a broken rubbed-in escape wheel jewel.

Hmm ... is the guard pin bent or is it just the angle of the photo? Add it to the list of issues for this watch.

If the shellac remaining is stable then there is no real need to remove that side of it, though one wonders why the other side is missing. Maybe not original, what is there looks a bit heavy and clumsy . The guard pin does look to bent, a picture from directly above will confirm it. This is the beginnings of understanding the escapement, adjusting pallet stone depth and how it affects the banking, guard pin and fork horn shakes. I can recommend a cheap good book if you can get it in OZ that deals with just the escapement, its old, over 100 years but all the principles still apply." Practical lessons on the lever escapement by TJ Wilkinson.  I think the rubbed in jewel is going to be harder to manage, needing some tool acquisitions. 

[VWatchie]

4 hours ago, GPrideaux said:

A question for those who are experienced with this: should I remove all the shellac from both sides, or will it be sufficient, if I can, to just clean one side up and apply new shellac to just that side? (I suspect the shellac is original to the watch so more than 100 years old.)

Removing the shellac from just one side would probably be very difficult. Additionally, there's a significant risk that the pallet stone will come out of position. In practice, cleaning the entire pallet fork from shellac will likely be easier and better. After a hundred years, the shellac has probably become very brittle, so I would think it's an advantage to replace all of the shellac.

4 hours ago, GPrideaux said:

Hmm ... is the guard pin bent or is it just the angle of the photo?

It looks bent. In an ideal scenario, it would be soft enough to bend back to a straight position. See the example under the heading "Guard Pin" in the following post.

[GPrideaux]

2 hours ago, Neverenoughwatches said:

Practical lessons on the lever escapement by TJ Wilkinson

Thanks, I've grabbed a digital copy from archive.org.

I'm starting to think that this watch is going to be beyond my ability for quite some time. I'm up to eight distinct issues with it, some simple (drowing in oil: solution - clean it; wad of fibres preventing the train from turning: clear it), some possibly non-issues (the guard pin might be one of these -- the base of it is not centred between the horns of the fork, but the tip of it does appear to be central), some looking intimidating but turning out not so bad (what looked like a bent balance wheel sprang back into shape when I released where the ends had been caught), some that need new skills but that I have some idea about what to do (the missing shellac, and balance end-shake so great that the pivots can come right out of their jewels: solution - bend the cock to be more parallel with the plate, I think) but some I still don't know how to deal with (the broken rubbed-in jewel). I think I'm not the first person to butcher this movement: I very much doubt this gouging out of the mainplate around the pallet jewel was how Joseph Bulova intended it to look (although the clear jewel and the pristine nature of the rubbed-in setting makes me suspect the 'adjustment' was done with the jewel in place):

 

[Neverenoughwatches]

21 minutes ago, GPrideaux said:

Thanks, I've grabbed a digital copy from archive.org.

I'm starting to think that this watch is going to be beyond my ability for quite some time. I'm up to eight distinct issues with it, some simple (drowing in oil: solution - clean it; wad of fibres preventing the train from turning: clear it), some possibly non-issues (the guard pin might be one of these -- the base of it is not centred between the horns of the fork, but the tip of it does appear to be central), some looking intimidating but turning out not so bad (what looked like a bent balance wheel sprang back into shape when I released where the ends had been caught), some that need new skills but that I have some idea about what to do (the missing shellac, and balance end-shake so great that the pivots can come right out of their jewels: solution - bend the cock to be more parallel with the plate, I think) but some I still don't know how to deal with (the broken rubbed-in jewel). I think I'm not the first person to butcher this movement: I very much doubt this gouging out of the mainplate around the pallet jewel was how Joseph Bulova intended it to look (although the clear jewel and the pristine nature of the rubbed-in setting makes me suspect the 'adjustment' was done with the jewel in place):

 

Looks to be some countersinking going on with more than just the lever jewel. There's a few different tools for removing and rubbing in jewels and settings, something surprisingly I don't own . Lets have a looksee at Ebay.

[tomh207]

1 minute ago, Neverenoughwatches said:

Looks to be some countersinking going on with more than just the lever jewel. There's a few different tools for removing and rubbing in jewels and settings, something surprisingly I don't own . 

Yet!

Tom

[Neverenoughwatches]

Couldn't find anything on Ebay just now, but found these in our archives. You could forgo the rubbed-in method if you aren't so fussed about originality and if that option isn't feasible. Just go for standard jewel replacement. 

[RichardHarris123]

I couldn't care less about replacing a rubbed in jewel with a friction fit one but I know others may disagree.