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Demagnetizer Recommendations

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I found an old hand held demagnetizer that looks like a blunt soldering iron.  It's used for demagnetizing the heads in a cassette deck.  I wonder if you could point it at a hairspring or other parts...has anyone tried one of these?

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5 hours ago, Wesley881 said:

I found an old hand held demagnetizer that looks like a blunt soldering iron.  It's used for demagnetizing the heads in a cassette deck.  I wonder if you could point it at a hairspring or other parts...has anyone tried one of these?

Not really a good tool for this.  To de magnetize the watch it needs to be inside a alternating field like the coil in the picture posted. 

This tool is for getting rid of polarization in a recording head. The magnetic field is really small and the probe end has to touch what you want de-magnetize, this would make it worse with a watch spring.

Just so you know a DC powered coil will magnetize things and a AC powered coil will de-magnetize them. 

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10 hours ago, Sleeper said:

Just so you know a DC powered coil will magnetize things and a AC powered coil will de-magnetize them. 

It is possible for an AC powered coil to magnetize a watch if the magnetic field strength is not varied during the process.  So, one way to vary the field strength is to slowly move the watch away from the coil while it is powered.  Another way is to charge up a capacitor and discharge it across the coil.  I've written an Instructable to build the latter type of demagnetizer.

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10 hours ago, Sleeper said:

Not really a good tool for this.  To de magnetize the watch it needs to be inside a alternating field like the coil in the picture posted. 

Thank you Sleeper and robmack for the insight, I was unaware of these effects.  I think I can spring 35 bucks or so for the proper unit!  When using a unit that you place the movement inside, what is the typical procedure?

Thanks again,

C  

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Demagnetizing process is pretty straight forward.  

  1. Insert the watch or tool into the coil
  2. Apply power to the coil
  3. Start to withdraw the watch or tool from the coil at a rate of about 15cm/sec. until you are about 75cm away from the coil
  4. Switch off the power to the coil
Edited by robmack

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On 6/6/2016 at 7:22 AM, ramrod said:

i love the video that you made. it's really the first time i've seen the escape wheel in full arc. is that the typical amout of "swing" that an escape wheel has? i thought that they had an almost full turn, but this one is about 270 degrees or so.

Escape wheel or balance wheel ??

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Back in the Stone age of computers we used degaussing coils about 10 inches around to fix old CRT monitors.  The Shadow mask on CRTs and TV sets was made of steel and would magnetize and cause bright spots and ghosting.  They had the hoops at Radio Shack for $12 till the around 2004. They are still around and still cheap. I see them at swap meets and on EBay now and then.  Looks like a needlepoint hoop with a power plug.

Mine works great for watches.      

Edited by Sleeper
error

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7 hours ago, Sleeper said:

Back in the Stone age of computers we used degaussing coils about 10 inches around to fix old CRT monitors.  The Shadow mask on CRTs and TV sets was made of steel and would magnetize and cause bright spots and ghosting.  They had the hoops at Radio Shack for $12 till the around 2004. They are still around and still cheap. I see them at swap meets and on EBay now and then.  Looks like a needlepoint hoop with a power plug.

Mine works great for watches.      

Even before the stone age those hoops were used on the CRT color TV's....

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On 26/3/2015 at 7:15 AM, SSTEEL said:
I have this one..
 
DSC09615 by Micky.!, on Flickr
 
Its probably exactly what Bergen sell, but at a fraction of the cost, it even has Bergeon branding.


I ordered one of these from china and am still waiting. Here is what I have73c3c696cde5a68d532fda0bb2f3e905.jpg


Sent from my iPhone using Tapatalk Pro

Edited by jdm
Please don't include pictures in quoting

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On 29/4/2017 at 2:59 PM, jdrichard said:


I ordered one of these from china and am still waiting. Here is what I have
 


Hi jdrichard how can I buy this Bergeon branded watch demag ? thanks Phil

Sent from my SM-N910F using Tapatalk
 

Edited by jdm
Please don't include pictures in quoting

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Hi jdrichard how can I buy this Bergeon branded watch demag ? thanks Phil

Sent from my SM-N910F using Tapatalk


Go to aliexpress.com and set up a basic account. You can also download the aliexpress app on your IPhone


Sent from my iPhone using Tapatalk Pro

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On 25 March 2015 at 5:44 PM, Don said:

I've got a movement that I think is magnetized. The hairspring coils are sticking and it makes a compass needle jump when placed over it. Here's a pic of the timer reading:

 

AS_1880_magnetized.JPG

 

 

I've watched Mark's videos and so I'm shopping for a demagnetizer. I'm looking at the Etic for about $80 shipped, the similar C&H model for about $30 shipped, the generic clones for $10 or so from China, this bad boy from Amazon (too heavy duity?) and some vintage Vigor demagnetizers. I'm a little (a lot) tool nutty and I hate buying really cheap and then spending again for one that works. Any recommendations?

 

Also, just for fun I was playing with the super slow speed function on my camera last night and made this video. Not great quality, but may be of interest.

 

https://youtu.be/JpLEB0kiHw0

 

Thanks,

 

Don like your video.  But back in the 70s I was struggling with magnetism couldn't let the screws go  having to poke them off the tweezers with pegwood and when I got them to sit in the hole they would jump out onto the screwdriver as soon as I went near them it was a nightmare. Then I found an old car battery charger took the transformer out stuck in a plastic box wired it up through a switch put a side light bulb on the secondery winding for on/off indicator and that was it heaven I could let go of screws and they didn't jump on to the screwdriver. Cost. Nothing. 

 

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On ‎2016‎-‎05‎-‎19 at 1:17 PM, oldhippy said:

The link is no longer working, and I'd really like to see that demagnetizing tool you were linking to. Can you please provide a new link?

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I use one of these on my own bench which is cheap, but really crap. It is either “on” or “off” with no gradual ramping to the magnetic field which means you have to slowly draw the item away from the demagnetiser in order to reduce the effect of the field slowly. Also, it’s designed for many mains voltages, but I suspect moreso 110/120V as the magnetic field seems too strong at 240V. Finally, the cable appeared to be rubberised, there was no earth conductor, and the live and neutral wires appeared to be some hard, white metal, and not copper. A bit dodgy, really. But it was cheap!

 

Watch-Repair-Screwdriver-Tweezers-Electr

We have a Greiner demagnetiser at my school which is excellent. Just press a button once and it automatically ramps down the magnetic field. Probably wasn’t cheap though. 

Edited by rodabod

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On 3/26/2015 at 2:15 AM, SSTEEL said:

I have this one..

Its probably exactly what Bergen sell, but at a fraction of the cost, it even has Bergeon branding.  


yeah, but that makes it a counterfeit item, assuming Bergeon isn't the vendor.  I have no issue with low cost knocks offs, and not one wants to overpay.....but a vendor stealing the brand?  

On 4/29/2017 at 8:59 AM, jdrichard said:

 Here is what I have
 

I've the same, K&D irrc, does a good job.   Doesn't yours work? 

Edited by measuretwice

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On 7/5/2018 at 1:35 PM, jdrichard said:

Need one of these old school ones
 

    yes,  "the old school" one is best.  but you need to learn how to use it.  it has many other uses,  like magnatizing a screw driver.  and then de magnatizing it.  vin

Edited by jdm
Please don't include pictures in quoting

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On 6/5/2018 at 10:59 PM, rodabod said:

I use one of these on my own bench which is cheap, but really crap. It is either “on” or “off” with no gradual ramping to the magnetic field which means you have to slowly draw the item away from the demagnetiser in order to reduce the effect of the field slowly. Also, it’s designed for many mains voltages, but I suspect moreso 110/120V as the magnetic field seems too strong at 240V. Finally, the cable appeared to be rubberised, there was no earth conductor, and the live and neutral wires appeared to be some hard, white metal, and not copper. A bit dodgy, really. But it was cheap!

We have a Greiner demagnetiser at my school which is excellent. Just press a button once and it automatically ramps down the magnetic field. Probably wasn’t cheap though. 

I have one of these too, and at best I hoping it hasn't magnetized any of my watches that I've tried to demagnetize. I've tested holding a compass to my watches before and after without any noticeable difference. Yes, I use it the way it is supposed to be used, holding the button while removing the watch from the device. And yes, I can sense a pretty strong magnetic field from the device while holding the button. I suspect this is a piece of junk solely designed to make money for the sellers and bring no use to the buyers.

I've tried it with some tools as well. Same effect. None! I run it 240V (Sweden).

Edited by jdm
Please don't include pictures in quoting

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1 hour ago, VWatchie said:

I have one of these too, and at best I hoping it hasn't magnetized any of my watches that I've tried to demagnetize. I've tested holding a compass to my watches before and after without any noticeable difference. Yes, I use it the way it is supposed to be used, holding the button while removing the watch from the device. And yes, I can sense a pretty strong magnetic field from the device while holding the button. I suspect this is a piece of junk solely designed to make money for the sellers and bring no use to the buyers.

I've tried it with some tools as well. Same effect. None! I run it 240V (Sweden).

I have one of the blue Chinese models and have used it with good results at 110V in the US . Works on my tools too .

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6 minutes ago, ricardopalamino said:

I have one of the blue Chinese models and have used it with good results at 110V in the US . Works on my tools too .

I suspect rodabod is right...

17 hours ago, rodabod said:

the magnetic field seems too strong at 240V

 

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