Page 1 of 1

Re-Magnetizing Old Bar Magnets

Posted: Mon Nov 07, 2016 2:42 pm
by CDBPDX
I would like to be able to remagnetize some old bar magnets that are pretty tired, not much strength. I've noticed that when I attach a neodymium magnet to a piece of metal for a short period of time, that piece of metal becomes magnetized. If I took a couple powerful magnets and attached them to an old bar magnet, would that work to strengthen it's magnetic power? I have an old magnetic reproducer and the magnet is kaput. The same for an old BLUE SPOT speaker with an almost dead magnet.

Would a magnetic pickup be a super pickup if a super strong neodymium bar magnet was used?

Thanks! Cliff

Re: Re-Magnetizing Old Bar Magnets

Posted: Mon Nov 07, 2016 3:20 pm
by 52089
Google will point you to several different methods each with its own pros and cons.

Yes, a Neodymium magnet can work and would be the preferred method for non-lab use. Other methods involve potentially dangerous levels of electricity. Stick to using magnets.

Re: Re-Magnetizing Old Bar Magnets

Posted: Tue Nov 08, 2016 3:42 am
by Marco Gilardetti
CDBPDX wrote:Would a magnetic pickup be a super pickup if a super strong neodymium bar magnet was used?
Yes, I see no reason why it shouldn't work. If there is room enough inside the pick-up, I would simply leave the "old" de-magnetized magnet in place, and let adhere to it a new small magnet (not necessarily neodimium, perhaps they're even too powerful!), taking care that the configuration of poles of the "new" magnet would polarize by magnetic influence the "old" magnet in the way in which the latter was intended to generate the magnetic field around the moving iron.

The pick-up will work even if the polarity is reversed. In principle, one just needs to have a megnetic field to surround the moving iron; then the pick-up will reveal the perturbations of said magnetic field generated by the movement of the moving iron across the field.

If you will do some experiments, please report here!

Re: Re-Magnetizing Old Bar Magnets

Posted: Wed Nov 09, 2016 3:41 pm
by howardpgh
Ask someone who works on Model T Fords.
They use magnets in the magneto and they usually need re magnetized.