demagnetized

[David Schwab]

I wonder if sticking all the new magnets on a metal keeper would help? Of course what magnet supplier is going to do that?

Just thinking out loud. This is an interesting topic.

The relative motion thing makes sense. Think about how you use a tape head demagnetizer. You have to slowly move it away to make the lines of flux smaller and smaller.

[solderstain]

The relative motion thing makes sense. Think about how you use a tape head demagnetizer. You have to slowly move it away to make the lines of flux smaller and smaller.

Bingo. And another example - go to Home Depot and buy one of those little things that are designed to help you magnetize the tip of a screw driver or some other tool. The instructions don't say to lay the tip of the screw driver next to the magnet and come back tomorrow. You rub the screw driver against the magnet. You can find this stuff with Google. There's all kinds of good stuff on the 'net about magnetizing and demagnetizing stuff.

[Arthur B.]

Bingo. And another example - go to Home Depot and buy one of those little things that are designed to help you magnetize the tip of a screw driver or some other tool. The instructions don't say to lay the tip of the screw driver next to the magnet and come back tomorrow. You rub the screw driver against the magnet. You can find this stuff with Google. There's all kinds of good stuff on the 'net about magnetizing and demagnetizing stuff.

Yup, but first a refresher course might be nice before going on to the more advanced stuff.

[Possum]

magnetizing

as far as I know magnets from suppliers ARE magnetized en masse. If you buy 5,000 alnico rod magnets they sure aren't going to sit there and magnetize each tiny rod :-) Yes they do vary in content, but if you do this for commercial purposes its best to charge your own magnets and get them unmagnetized to start. Relying on magnets charged at the supplier is just dumb. Alot of those weak magnets from the supplier will charge right up. All you really need is a big ass neodymium magnet to charge them with. The magnets Stew Mac sell are too weak, too small to do the job right. I finally broke down and got a real magnet charger like Wolfe has, very similar to what Leo Fender used except it plugs into the wall. The problem with the neo magnets is they are difficult to charge unoriented alnico like 2 and 3, 4. The neo is always "on" where a magnet charge you shut off when charged so the charger poles don't keep pulling and mess up the direction as you remove the magnet.

[EtLa]

I finally broke down and got a real magnet charger like Wolfe has, very similar to what Leo Fender used except it plugs into the wall.

me too but an old heavy (~60 lbs) one used to charge car magnetos, a deal $50. It works with a 12 volts car battery.
I was very surprised when I found the doc on the net.

[twogeez]

Supposedly, SD learned about demagnetization with one of Sting's Teles... he rode on a trolley to a recording session with a Telecaster guitar with new SD pickups in it, and his seat for the ride was over one of the trolley's electric drive motors. In the story, this almost totally demagged the pickups.

Computer monitors, TV's, microwave ovens, bulk tape erasers, neighborhood electricity transformers, arc welders, big speakers, really any source of strong magnetic fields can demag Alnico.

IMHO Al5 is the most resistant to demagnetizing, lower grades are easier to demag.

Ken

I think that was actually Andy Summers guitar if I remember the story correctly.