Watch Keeps Magnetizing

[mtgjr]

My D serial 16710 has run at -1 sec/day very consistently for the last couple of years, since it had a complete overhaul. A couple months ago, I did a random accuracy check and realized it had started to GAIN about 6 sec/day out of the blue. There had been no impacts or other external factors that would explain the change. Suspecting possible magnetism, I downloaded the Lepsi app and, sure enough, according to the app my GMT was magnetized.

I ordered one of the cheap, blue demagnetizing devices (blue box with black button and red indicator light) off eBay and it worked like a charm. The Lepsi app no longer detected magnetism from my watch, and it went right back to running -1 s/d. Problem easily diagnosed and solved! Or so I thought.

Over the last couple months, it's happened two more times. Both times the watch started randomly running fast, it triggered the Lepsi app, and it returned to normal after holding it over the demagnetizer as prescribed.

My question is, has this happened to anyone else, and does anyone know why this might be happening? The only environmental factor that I can think of, which might be causing it, is a new iPad that I use daily, which has a cover that stays closed with the help of magnets. Thinking back to the first occurrence, it may well have coincided with me getting the iPad and cover. Could this be the culprit? I'd think a modern Rolex would be harder to magnetize than that, but apparently not in my case.

Any ideas?

[Etschell]

could be but seems unlikely.

[kauffee]

I feel like I’ve read a bunch of posts here and on WUS about iPads and iPad covers magentizing watches. Try a different iPad cover first.

[aussiejoe]

Had a similar experience with my Speedmaster. Drove me crazy. Turned out to be my money clip. Those iPad magnets may be small, but they are very strong.

[tamiya]

Yes be very careful with iPad smart covers. There's a magnet 3" down from top right corner to turn on/off. Old style Left hinge, if you've got the Apple stick-on hinge covers there's a pair of magnets about 5" apart.

I've ditched all my stick-on hinge covers so I only have to worry about 1 magnet.

If I'm on a plane resting on armrest I equally flip my watch face around to inner wrist. This is exactly where the hinge of iPad ends up when I'm cradling it.

[The Libertine]

Originally Posted by aussiejoe

Those iPad magnets may be small, but they are very strong.

Really? Strong enough to “magnetize” a watch?

[cop414]

While I've never had a problem with my magnetic iPad cover I guess that this could happen. Try a different cover/case for a couple months and see if that solves the problem.

[beshannon]

Originally Posted by The Libertine

Really? Strong enough to “magnetize” a watch?

Agreed I do not understand this.

Also how can an app tell if a piece of metal is magnetized?

[mtgjr]

Originally Posted by beshannon

Agreed I do not understand this.

Also how can an app tell if a piece of metal is magnetized?

It works extremely well, actually. Makes use of the iPhone's built-in magnetic sensor that's part of the internal compass.

[tamiya]

I can only describe it layman like how I see it.

Our watches run off a balance wheel, basically a rotational/torsional pendulum. It's like a tiny bike wheel on axel, it'll be freespinning if not for the hairspring that's wound between axle and rim. Hairspring is wound around many times but the coils do not touch each other. Hairspring winds & unwinds once every spin of wheel.

Under normal operation, balance wheel spins lock to lock nearly a full circle, say 300degs. It should spin equally between normally resting midpoint, where a lever takes a drive off from.

If the hairspring gets magnetised, it starts sticking up the coils and the spring effectively gets "stiffer" which makes the wheel spins faster. The sticky coils also swing differently between wind & unwind, won't be equal any longer. Your pendulum swings like a lopsided seesaw.

Timegrapher machine &/or app picks up these beats via its microphone. It times these beats and the intervals between each tick vs tock... and IMHO a sticky hairspring should show up as an erratic but recognisable irregular pattern.


I don't know how "easy" it is for a modern Rolex to get magnetised, not interested in finding out. Had a good friend come by recently and we were checking out my collection of tiny neo magnets I don't wear mechs when I work with magnets and I made him take off his shiny new watch and leave it at the other side of the room.

It's a Milgauss but still, not taking chances.

[Ruud Van Driver]

I'd get a second opinion on your watch being magnetised by placing it near a proper compass.

[tamiya]

Originally Posted by Ruud Van Driver

I'd get a second opinion on your watch being magnetised by placing it near a proper compass.

not quite convinced the SS case necessarily stays magnetised after the offending magnet is removed; SS often won't hold the charge like mild steel or Spring steel.

[JKolmo]

Hmmm, got interested by this and downloaded the Lepsi app. It appears all of my watches are alledgedly magnetized. They all however run just fine IRL. Seems like a bogus app IMO. Besides, if your watch is magnetized it will not gain as little as only 6 secs per day.

[carava501]

Switch out your ipad cover.

[sanosan34]

For anyone using the Lepsi app, use it in calibrate mode so you can see a numeric reading of magnetic strength. It is useless to say a watch is magnetized or not magnetized because the degree of magnetism can range from weak to medium to strong and everything in between.

[The Libertine]

Originally Posted by JKolmo

Hmmm, got interested by this and downloaded the Lepsi app. It appears all of my watches are alledgedly magnetized. They all however run just fine IRL. Seems like a bogus app IMO. Besides, if your watch is magnetized it will not gain as little as only 6 secs per day.

It will also be erratic - not a consistent +6.

[polaris72]

Could it be a laptop, speaker, or any other electronic device (watchwinder)?

[mtgjr]

Originally Posted by The Libertine

It will also be erratic - not a consistent +6.

Not necessarily true.

[meganfox17]

Originally Posted by mtgjr

is a new iPad that I use daily, which has a cover that stays closed with the help of magnets. Thinking back to the first occurrence, it may well have coincided with me getting the iPad and cover. Could this be the culprit? I'd think a modern Rolex would be harder to magnetize than that, but apparently not in my case. Any ideas?

Have you visited the Omega Forum>Modern Omega Watches Section before Sir ? Threads on Magnetism and Anti Magnetic properties are so frequently brought up that nothing is spared from discussions, from Apple iPads to Large Hadron Colliders (LHC) and even mentioning about the World's Strongest Magnet that sits in a Magnetic Field Lab in Florida State University.

Anyway your suspicions are correct and spot on. The culprit is indeed the smart magnetic cover on the iPad ( when dissembled has something like 21 magnets in situ ) AND the case with the built-in magnetic closure . Would you believe me if I told you that a iPad mini itself has stronger magnets for the cover closure than the smart cover itself ?

Should you be interested in identifying the source of magnetism, then consider purchasing one of those very cool handheld user friendly Gaussmeters with axial probes to measure the strength of EMFs near and around the iPad...
I know it's a little expensive ... Just sayin'

[aussiejoe]

Originally Posted by The Libertine

Really? Strong enough to “magnetize” a watch?

It doesn’t need to magnetise the entire watch, just the hairspring. If it is magnetised, I would certainly expect it to run considerably faster. Mine was five minutes per day.

[Ruud Van Driver]

Originally Posted by tamiya

not quite convinced the SS case necessarily stays magnetised after the offending magnet is removed; SS often won't hold the charge like mild steel or Spring steel.

It’s more the running gear I was thinking of, not the case. When my 359 was misbehaving, the first thing Panerai did was place the watch near a compass.

[meganfox17]

Originally Posted by JKolmo

Hmmm, got interested by this and downloaded the Lepsi app. It appears all of my watches are alledgedly magnetized. They all however run just fine IRL. Seems like a bogus app IMO. Besides, if your watch is magnetized it will not gain as little as only 6 secs per day.

I can offer an explanation for the bizarre readings Sir. The App uses the built- in magnetic sensor in the smartphone that behaves exactly like a compass needle. Also remember that a compass has magnet it in (like your smartphone) , this means the compass needle is always drawn towards the Magnetic North. Putting it in another way, placing a compass or a smartphone Lepsi app near a watch and saying the watch is magnetized just because needle is moving isn't exactly the case. Many a time, the compass or Lepsi Test is done incorrectly.

The old school way (now obsolete) was placing a tiny compass OVER the balance spring (BS ) and watch for the needle to move at the same rate as the balance was beating !

Now watchmaker I know use the timing machine and observation of the BS or like I suggested in my previous post , the Gaussmeter ...

[tamiya]

Originally Posted by Ruud Van Driver

It’s more the running gear I was thinking of, not the case. When my 359 was misbehaving, the first thing Panerai did was place the watch near a compass.

Yeah, no, that's what I meant.

Big hunk of metal with hollow cavity acts as a Faraday Cage and shields whatever inside it from RF & magnetic fields; it would take a big magnetising hit for fields to get strong enough to affect inside - but not impossible.

But after the hairspring is magnetized it's only weakly magnetic, it most likely won't be strong enough to detect any magnetism outside of the big hunk of SS case. Faraday Cage works both ways.

SS case may or may not stay magnetized after the hit. But if a compass needle shows some deflection, imho much better chance it's from the case rather than what's inside. But merely as an indicator, yes worth investigating further.

Proper watchmaker (of which I don't even play one on TV) would yank out whole balance to check that for magnetism.

[tamiya]

Originally Posted by meganfox17

The old school way (now obsolete) was placing a tiny compass OVER the balance spring (BS ) and watch for the needle to move at the same rate as the balance was beating !.

Yes. i had a bunch of tiny compasses back then some are just a naked needle to be balanced on the point of a pin.

But caution as compass needle itself is magnetic and if you get the compass too close to hairspring it can cause more magnetism than you started out with.

[Ruud Van Driver]

Originally Posted by tamiya

Yeah, no, that's what I meant.

Big hunk of metal with hollow cavity acts as a Faraday Cage and shields whatever inside it from RF & magnetic fields; it would take a big magnetising hit for fields to get strong enough to affect inside - but not impossible.

But after the hairspring is magnetized it's only weakly magnetic, it most likely won't be strong enough to detect any magnetism outside of the big hunk of SS case. Faraday Cage works both ways.

SS case may or may not stay magnetized after the hit. But if a compass needle shows some deflection, imho much better chance it's from the case rather than what's inside. But merely as an indicator, yes worth investigating further.

Proper watchmaker (of which I don't even play one on TV) would yank out whole balance to check that for magnetism.

Sounds reasonable.

I think the use of the compass is a precursor to getting an idea how bad things are. If the compass needle deflects, then the watchmakers knows it’s magnetised and can crack on accordingly. If it doesn’t, he might try other rudimentary checks before yanking the guts out of the watch.

I’m just guessing here. Something like this needs the technical expertise of a grown-up like Vanessa.

[tamiya]

You & me both! I sooooo wish Vanessa was my Girl Next Door

Hahaha ok got confession to make spent all night playing with compasses

Background fillin... like many here got more pieces than wrists, fleet get spread out stored in several different spots. One such spot, uh, let's just describe as "furry butt" (FB).

One longterm piece that's been living under FB for decade if not 2, I discovered running rather erratically recently. Have been wondering why & had thought it was telling service was due.

Tonite after all the talk here & remembering I bought a bunch of new compasses recently, I laid them out & brought the watch near.

Yes the compass needles deviate!! okay yay yippee yay

Started trying each part of watch... hmm, interesting... strongest magnetism was at... the clasp?! yep no doubt... the clasp and half a bracelet, strongly magnetised.

But the SS case (top/bottom/2sides) & the other half bracelet, nada! No response from compass. Intriguing! Lends belief that oyster case might resist staying magnetised, but insides could remain affected.

Vintage Clasp is stamped sheet steel type but bracelet is solid link.


As for source of magnetism? Well, Mr FB is a grumpy mechatronic talking teddybear and the compasses strongly point that his butt contains magnets, probably motor or speaker.

Whoops!