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Posted

Hi all. 

I recently acquired a really lovely Molnija pocket watch in great shape overall. I have dismantled it and already cleaned it and have noticed that all the parts appear to be highly magnetized as evidenced by all the parts sticking to each other like that nasty stuff to a blanket. I don't have a demagnetizer but will have to get one without question, which leads to a couple of questions; hopefully I'm not repeating something that's already been answered in the forums.

First question is should I go for the Etic demagnetizer that Marc mentions in one of his videos, or get the cheap Chinese equivalent - or is it not equivalent, or would it be better to get the more expensive tunnel type that you pass the whole watch through? Sorry, that's three questions in one, but they are related.

Second question is, can I still assemble the pocket watch while I wait for the demagnetizer to arrive then demagnetize the assembled watch in one fell swoop - or should I wait for it to arrive then individually demagnetize the parts first before assembly?

Third question is how on earth did the parts become so magnetized in the first place; Is Russia now a hot-bed of magnetic activity?

BTW, I can't afford a nice Bergeon demagnetizer, or more correctly I can afford it just, but can't afford the divorce that would shortly follow its arrival. 

Thanks, I'll await your collective wisdom before doing anything else with the watch. 

Cheers from sunny Edmonton

  • Like 2
Posted
Hi all. 

I recently acquired a really lovely Molnija pocket watch in great shape overall. I have dismantled it and already cleaned it and have noticed that all the parts appear to be highly magnetized as evidenced by all the parts sticking to each other like that nasty stuff to a blanket. I don't have a demagnetizer but will have to get one without question, which leads to a couple of questions; hopefully I'm not repeating something that's already been answered in the forums.

First question is should I go for the Etic demagnetizer that Marc mentions in one of his videos, or get the cheap Chinese equivalent - or is it not equivalent, or would it be better to get the more expensive tunnel type that you pass the whole watch through? Sorry, that's three questions in one, but they are related.

Second question is, can I still assemble the pocket watch while I wait for the demagnetizer to arrive then demagnetize the assembled watch in one fell swoop - or should I wait for it to arrive then individually demagnetize the parts first before assembly?

Third question is how on earth did the parts become so magnetized in the first place; Is Russia now a hot-bed of magnetic activity?

BTW, I can't afford a nice Bergeon demagnetizer, or more correctly I can afford it just, but can't afford the divorce that would shortly follow its arrival. 

Thanks, I'll await your collective wisdom before doing anything else with the watch. 

Cheers from sunny Edmonton

As a fellow Canadian, buy the good one it comes with a voucher for a lawyer

Posted

My very particular answer is, wait for the demagnetizer. Of course you can work on the watch and then demagnetize but when metal is magnetized lots of particles are naturally attached to it. The magnetized watch is no different so if you demagnetize after cleaning, chances are all the stuff that was attached to the parts (due to magnetism) will be dancing inside the watch and doubling as "sand paper".

If you decide to demagnetize the separate parts you are in for a surprise since the cheapo demagnetizer (regardless of where it comes from) need some sort of "theatrical performance" on your part to work, i.e. you grab the part and place it on the marked spot on the demagnetizer, press the button and start moving -- hopefully with your other hand -- the part away from the demagnetizer, slowly, evenly and in a wide sort of gesture. Eventually, when the part is as far away as possible from the demagnetizer as you can, you let go of the button and the part should be demagnetized...or you have to repeat your performance over again.

This is impossible to do with a bunch of parts regardless since they all acquire a mind of their own and start jumping in the magnetic field and never get demagnetized...or very little if any...or you have to "perform" for each of the 20 plus parts in a watch, and the screws,  and ...well you get the idea. Not a good idea to do it with a hairspring assembly by itself...

Posted

You could put all your parts in some kind of container then de magnatize the whole lot it once.

  • Like 1
Posted

I have both the cheap Chinese copy of the Etic, and a vintage pass through tunnel type of de-magger and to be honest they both do the job, although I find the tunnel type is probably slightly more efficient (and looks a hell of a lot cooler on the bench although that's just my weird sense of aesthetics).B)

I wouldn't spend the extra cash on the big name brands, a de-magger is a de-magger, essentially a coil of copper wire. You may get a better switch on the expensive one but if that bothers you then consider picking up a better quality switch from your local Maplins or Radio Shack and swapping it out on a cheap unit. You still save your money and get the best of both worlds.

 

As Bobm12 says it may be wise to de-mag prior to re-assembly. If there is that much magnetic swarf sticking to the parts then I would want to make sure that they are clean before it goes back together, that way there is much less risk of the debris ending up back in the watch.

I actually de-mag the movement prior to disassembly so that when the parts go through the cleaning machine any swarf is easily flushed away from the parts. I once made the mistake of putting the balance from an ESA 9154 (balance wheel electronic with permanent magnets attached to the wheel) through what looked like reasonably clean solutions in the cleaner, only to find it completely covered in iron filings that it had picked up from previous wash cycles when it came out. It took time, patience, and Rodico to sort out but it made me think about better cleaning practice.

It is also good practice to de-mag the re-assembled movement after cleaning as some cleaning machines can induce magnetism.

 

As for de-magging the parts separately that sounds like a right bore. I would replace the balance / balance cock assembly back onto the main plate to constrain it, and then put everything into some kind of container (with lid) and do it all at once like Cad101 has suggested.

 

As for how it got that way, who knows. I used to work in the fabrication department at Lotus Cars and was always advised to take my watch off before going onto the shop floor, mainly because of the spot welders, but leave it sitting on top of a Hi-Fi speaker for a couple of days and you would probably do the trick.

  • Like 1
  • 2 weeks later...
Posted

Well I did order an Etic demagnetizer in the end, however delivery is really slow and it won't be here for a few weeks so I had to make do with something else in the meanwhile. I read up in the ether world and there were several seemingly good home made designs that anyone could craft, however when I tried one of them I was stymied when I tried to tear an old transformer apart to use it as the laminations were all glued together with a hard varnish. Back to the drawing board. 

The solution I came up with, and that worked quite well, was to simply grip the edge of neodymium disc magnet in the jaws of an electric drill and rotate it at high speed then hover the parts by it and slowly draw them away. I did this twice with the particular parts I was having trouble with and they become completely and magically demagnetized.

I can't think of anything simpler frankly as most people have an electric drill and the magnets are available anywhere. Total cost was about $1. I'll be interested to compare it to the Etic when it finally arrives, though I'm sure the Etic will win the contest - I really hope so as the Etic is about 80 times more expensive than the simple magnet shown. 

I'm sure you'll all be upset to hear that the Oilers didn't make it to the playoffs - again!

Demagnetizer.JPG

  • Like 2
Posted

Awesome and I have no words! I looove that demagnetizer! Had I known that before, I might have saved a lot of money!

Yes, that oilers news are bad news. Any reason they didn't make it?

Cheers,

Bob

PS. I'll be interested in the demagnetizer comparison!

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