Magnetized Balance

[icius]

Hey all,

 

I was working on an ST 1686 and got down to the point of analyzing the balance/hairspring.  I determined that the hairspring was magnetized as the coils were sticking together when prompted (i.e. slight pressure on the outside of the hairspring).  This had already been through a full cycle of the cleaning machine as well as an additional dip in naptha so I'm pretty confident that it is not some kind of contamination.  

 

I picked up this item last week from Esslinger:

 

 

I had the balance removed from the balance cock so I thought it would be a great first test for my new demagnetizer. 

 

I followed Mark's procedure in 

 

https://youtu.be/E6_KOcc4eD4

 

Started with the balance almost touching the demagnetizer,  pushed the button, and slowly pulled it away from the demagnetizer at about 45 degrees.  What I expected to happen was the coils to pop apart as the magnetism was removed.  

 

Nope.

 

Much googling and 20 different techniques later I still have a magnetized hairspring.  Is it possible I have a defective demagnitizer?  I see the hairspring jump when I push the button so it is definitely doing something.  

[Geo]

A couple of things.

1) Keep the balance in the movement when you use the demagnetiser to lessen the chance of the hairspring getting tangled during the process.

2) It's not unusual to have to repeat this a couple of times to get the result you want. It is possible to inadvertently magnetise using this tool. This has happened with me a few times, but if you repeat the process it will work.

3) Is it definitely magnetism, or could there be oil on the hairspring?

[Horlogerie]

More than likely the coils are contaminated with the cleaning/rinse fluid.

The only product I have found that works to clean hairsprings is actual hairspring cleaner, everything else I have ever tried and used leaves a residue and the coils stick.

[bobm12]

Excellent advise, Robert, je vous remercie! I've encountered the same problem and was wondering what was the issue!

 

Cheers,

 

Bob

[Blacklab]

More than likely the coils are contaminated with the cleaning/rinse fluid.

The only product I have found that works to clean hairsprings is actual hairspring cleaner, everything else I have ever tried and used leaves a residue and the coils stick.

Dead right. Had problems like this in the past, so always keep a jar of Essence of Renata (or similar) exclusively for the final hairspring dip. Funnily enough I have just reassembled a Seiko 6619 today, hairspring clean as a whistle, coils not sticking etc. timegrapher all over the place. A quick blast on the demagnetiser and all is fine. If its not one thing its the other.

 

Is it worth demagnatising every mechanical watch as a matter of course?

[icius]

Seems like a good idea then. I have hairspring cleaner in my cart at Esslinger.

Blacklab, seems like it couldn't hurt as a matter of practice to just demagnetize.

[Blacklab]

Just cautious, as I seem to remember someone mentioning on another forum that it can occasionally cause magnetisation. Don't know how true that is.

[Geo]

Don't know how true that is.

I mentioned it in my above post 'cause I've experienced it myself.

[Horlogerie]

I don't normally demagnitize all movements that I service. Modern movements with modern hairsprings are not magnetic, so there is no reason to try and demagnitize them. Certainly older movements with blued steel hairsprings can get magnitized, but as stated above simply demagnitizing for the sake of demagnitizing everything can be a problem. In some cases I have had a real problem getting small parts to demagnitize, even after repeated attempts, so I only demagnitize when I know it's already magnetic.

[Geo]

What demagnetiser do you use Robert?

[Horlogerie]

At the moment I have a small Etic model. Bought it because the price for other models was completely unrealistic, 685 Pounds is nuts. The Etic does a decent job and does work, but I sometimes wonder if the low cost means that it's not really up to the task, I do have to repeat the operation now and then.

I had a really nice demagnitizer before I left Canada, but it was of course 110V and no good here. It was old but made for the Magnaflux Non Destructive Testing industry, and was excellent. I would love to find another one for 220V, the search continues.

[Geo]

I have used the same one as icius for a few years, but recently invested in an Elma unit. I like just having to press the button instead of pressing and pulling away.

[Blacklab]

I mentioned it in my above post 'cause I've experienced it myself.

Ooops! apologies Geo, missed your post. I really must pay attention in class (I think they used to say that too me a school a lot, but I wasn't really paying attention at the time).