Seiko 6309A Pallet fork not locking?

[BillM]

Hi there,

I am rebuilding a Seiko 6309A movement and have it all cleaned and mostly back together, however after installing the pallet fork I noticed that when I add a bit of power to the gear train the pallet fork oscillates back and forth without stopping/ locking. I installed the balance anyway and tried to get to run, but of course it will not run correctly.

Any ideas about what might be the issue here and how to fix it? 

I'm new and have not come across this before, so any help would be greatly appreciated.  

Thank you,

Bill

OK, well I figured it out, one pallet stone was slightly out of place. Not sure how it got moved, clearly I did it somehow.

I was able to move it back into place and it works fine now. 

It felt like the stone was still held tightly, so I don't think I'll need to redo the shellac. 

[JohnR725]

2 hours ago, BillM said:

It felt like the stone was still held tightly

You might want a mixup some shellac and alcohol and make a glue and just touch it up on the stone that was loose. Because If it moved one time it may move again.

[BillM]

Yes, I agree, I've never done that before, so I’m in research mode right now.  Looking at making a pallet warmer, hopefully I can just re-melt what’s there and that’ll tighten it back up.  

Edited January 13, 2023 by BillM

[BillM]

OK, So I made a simple pallet warmer and tried to re-melt the shellac, but the stuff just would not melt, in fact one piece came loose and I put that piece on a separate
copper plate and tried to melt it, it simply got darker and darker but did not melt.
So I guess I'll have to order some shellac and and replace what's on the pallet currently.
Great learning experience, sure hope I don't mess it up, LOL!

[JohnR725]

4 hours ago, BillM said:

So I made a simple pallet warmer and tried to re-melt the shellac, but the stuff just would not melt

It don't actually know but it's very possible that your pallet fork has epoxy not shellac. Because normally when heated up it should melt there can be variations in the quality a shellac but it should melt eventually.

[BillM]

8 hours ago, JohnR725 said:

It don't actually know but it's very possible that your pallet fork has epoxy not shellac. Because normally when heated up it should melt there can be variations in the quality a shellac but it should melt eventually.

Hmmm, ya I didn’t think of that for some reason, but makes complete sense now that you said it.  

[BillM]

I found this old container of flake shellac in my late fathers stuff and tried to melt it, strangely it will not melt, it gets soft and then turns to rubber and then just crumbles. 
I used a very controlled heat plate with a thermocouple, not just an open flame.  
it also does not dissolve in isopropyl alcohol. What the heck? 
 

[dadistic]

Different stuff than watchmakers use. To dissolve this, use ethanol, or denatured alcohol (ethanol with nasty stuff to keep you from drinking it).

Cheers!

[JohnR725]

3 hours ago, BillM said:

isopropyl alcohol. What the heck? 

Isopropyl alcohol has amusing properties. If you look up on woodworking groups there are Some people that claim it will dissolve the shellac. But that alcohol is used as the final rinse as our cleaning machine at work and it does not dissolve the shellac. But I know the shellac itself very use even the watchmakers kind varies over time and because watchmakers acquirer old stuff that can be quite a bit of time were some is better than others.

My current favorite is one of the watchmakers locally purchased a pound or so of  flake shellac from the woodworking store and gave everyone a little bag of it. This stuff melts beautifully and flows really nice. You put a little chip on top of the fork and just heated up and it flows beautifully.

 

[BillM]

1 hour ago, dadistic said:

Different stuff than watchmakers use. To dissolve this, use ethanol, or denatured alcohol (ethanol with nasty stuff to keep you from drinking it).

Cheers!

I have some soaking in Methanol and it’s not devolving in that either.   
 

[BillM]

I received my new shellac today and ran some tests, this stuff melts great and works best at 110c-115c (made a new pallet heater too).

Everything went well, got bit too much on one stone, but it looks ok.
I left the original "epoxy" in place and just added new shellac at the back of the stones. (some shellac flowed over and around that old epoxy). The stones now feel tight and look ok to me.
I installed the pallet and ballance and everything is back up and running. 
Thanks for the help-
Bill