Pallet jewel - shellac

[PeterS]

I wanted to test the travel between the banking and the guard pin and managed to loosen the exit pallet jewel in the process of doing so. No harm done, it's NH36 I bought for testing. The exit jewel is under the pallet bridge, very much impossible to test it. I couldn't get there with an oiler so I used a curved dental too. I wasn't applying much pressure, at least I don't think so but considering the scale, the dental tool is quite large. After all this, I didn't manage to test the travel on the exit jewel, entry was fine and accessible.
Couple of questions:

Was it my fault or was the jewel not secured properly? I thought you'd have to heat the shellac to loosen it or apply a lot of pressure to remove it. Not that you'd want to do it with pressure without heating it first, I'm just trying to work out why it happened. This is a new movement btw.

Do I need to remove the old shellac and apply new? It is as secure as it can be with a loose jewel, it runs well when I assemble it and put it on the timegrapher. The jewel doesn't move back and forth, it pivots down if I apply medium pressure. I'd be tempted to heat it and add more shellac. I'm sure the correct procedure would be to remove the shellac from the jewel and the fork and apply new but it is in perfect position so I'd rather just heat it and add little more shellac.

 

[JGrainger]

In theory adding a tiny bit of shellac to a pallet jewel seems like a straight forward task, largely that (on it's own with no precise adjustment required) is pretty simple. Despite that, it does take a bit of practice - drawing the shellac into a fine point of suitable thickness so it doesn't just melt and float about in heat current above a traditional tool for the purpose.. and adding more might not be necessary.

You could try reheating the pallet on a brass plate, so that the shellac reflows.. you can try sticking a bit of shellac on the plate to know when it should be warm enough to melt.

[PeterS]

OK, so it is not necessary to remove the shellac. I'll try reheating it first and see whether it's going to set. If not, I could perhaps try a very small flake/shaving on the top and heat it until it starts melting.
It sounds straight forward, but considering the size of the pallet jewel, I know it's going to be a nightmare at first.

I'm going to have to make the jig first of all. I'll have to look for a thick piece of brass or copper, 1/4 inch ideally. According to the book I have here it is better as it retains heat longer hence doesn't have to be reheated as often. Cousins only sell 3mm sheets though.

[saswatch88]

OK, so it is not necessary to remove the shellac. I'll try reheating it first and see whether it's going to set. If not, I could perhaps try a very small flake/shaving on the top and heat it until it starts melting.

It sounds straight forward, but considering the size of the pallet jewel, I know it's going to be a nightmare at first.

I'm going to have to make the jig first of all. I'll have to look for a thick piece of brass or copper, 1/4 inch ideally. According to the book I have here it is better as it retains heat longer hence doesn't have to be reheated as often. Cousins only sell 3mm sheets though.

Go on ebay and by a vintage pallet warmer/ jewel setter. They make the job a 1000 times easier. A combination tool is also good to use and they are more common than the jewel setting warmers. Like my grandfather use to say “they just dont make them like they use too” i believe that also applies to watchmaker tools.

 

 

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[jdm]

4 hours ago, saswatch88 said:

Like my grandfather use to say “they just dont make them like they use too” i believe that also applies to watchmaker tools.

But in some cases one can make his own, below our Host Mark Lovic demonstrates

 

[nickelsilver]

Reflowing the shellac should work, but if you want to add some it's good to make a "shellac applicator"; heat a corner of shellac above your flame until it just goes liquid, then stick a toothpick in and pull away. You'll have a long strand, break this off a few mm away from the end of the toothpick and you can now apply it where and how you want.

[PeterS]

3 hours ago, nickelsilver said:

Reflowing the shellac should work, but if you want to add some it's good to make a "shellac applicator"; heat a corner of shellac above your flame until it just goes liquid, then stick a toothpick in and pull away. You'll have a long strand, break this off a few mm away from the end of the toothpick and you can now apply it where and how you want.

That's really good. Far better than the flake/shaving I was thinking of.

[PeterS]

I'll see what is on Ebay. To speed it up, I'll probably end up making one from the 3mm piece if I can't find anything there for a reasonable price.
If I find a thick piece of brass/copper I'd like to make one as per the picture bellow.
The 'slot' and the hole are there to stop transferring heat from one side to another leaving the other side cool.