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Demagnetizer Recommendations


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I have used diy demagnetizers that work the same as the versions you list - basically a coil running of AC current - and they work ......ok. You have to remove your watch/movement/part etc slowly from the magnetic field and some times this does not work as one would hope. I have been thinking of building a automatic version for some time now, and  last week stumbled on this page while browsing the subject. Simple and genius - charge a capacitor and then use the capacitance and power stored to form a LC-resonator with a inductor - viola, an automatic demagnetizer!

In my version I use two 230V to 12V transformers for isolation.

Here in my version:

 

147764423593527500_resized.jpg

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Charge for three seconds and then press DeMag and your done - works wonders and I am never going back to the coil version!

So if you can invest 60min of building time - I would go fo a automatic version!

 

Edited by RCDesign
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If you are just a hobbyist I can recommend this one from E-bay at £11.99. I have one, and although it looks rather crude it is very effective, certainly as a starter unit. You can always look at a more expensive one later on. This one not only demagnetises small things like watches, but it also demagged my kitchen sharpening steel. Just search 'watch demagnetizers' on E-bay. The 'Cube' is good for finding pinged parts off the floor!

PS. You may have to put a three-pin plug on it.

 

s-l225.jpg

Edited by fjseal
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On 30/10/2016 at 11:13 PM, fjseal said:

If you are just a hobbyist I can recommend this one from E-bay at £11.99. I have one, and although it looks rather crude it is very effective, certainly as a starter unit. You can always look at a more expensive one later on. This one not only demagnetises small things like watches, but it also demagged my kitchen sharpening steel. Just search 'watch demagnetizers' on E-bay. The 'Cube' is good for finding pinged parts off the floor!

PS. You may have to put a three-pin plug on it.

 


Thanks for the advice. I did see this one on eBay before. However I skipped past it, thought it looked a bit ropey. Good to know it can do the job, I will take a good look at it. Funny how we can be drawn to things by the way they look...

 

Edited by jdm
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  • 2 months later...

Yes they do work, a few folk on the forum have used them with success including myself.  When using one, hold the watch on or very close to it then press the button on the unit.  While holding the button down, slowly pull the watch away to a distance if 450-600mm before releasing the button.  Do not keep the button held down for longer than ten seconds at a time or the unit will overheat.  

You may have to repeat this a few times to get rid of the magnetism, but it's the same with any demagnetiser.  Don't assume that the movement will be demagnetised after one go.  Another thing to remember, it is possible to inadvertently magnetise a movement with a demagnetiser.  If this happens, just go through the process again until you get the correct result.

 

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  • 3 months later...

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
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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
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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
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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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  • 3 weeks later...
  • 10 months later...
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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  • 3 weeks later...
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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