Favorite rough unpolished sand cast alnico bar magnets?

[glaze]

I just received my first order of bar magnets from Shea at Magnetic hold. I requested the sizes I wanted and requested unmagnetized if they had them, but if they did not then send me my order magnetized. I received nice polished alnico bar magnets that were magnetized from them. I have read many posts that the Magnetic Hold magnets sound great, so that is why I ordered from them.

Now I want to buy some good vintage sounding rough unpolished sand cast alnico bar magnets that are unmagnetized. I want to magnetize them myself. I have read many magnet posts over two weeks on this forum and still have not decided what supplier to buy from. Have any suggestions?

I am working on winding vintage style P90's. Guitarist posted a video on a 1957 Gibson Les Paul Junior with a P90 that sounds fantastic. I want to try to make a P90 close to that with degaussed magnets. I know this is a tough thing to do because some people who review pickups will say no newer made p90 pickup has come exactly close to originals. Some people say the magnet is the secret in the originals.

[LtKojak]

I want to magnetize them myself.

Unless you own a industrial-type, zap magnetizer, getting bar mags unmagnetized is not such a good idea.

The only alnico type that can be charged to full-saturation using the most potent (N52) Neo mags is A3.

[big_teee]

Unless you have lots of money to get custom made stuff, you have to use what's available.
I know the rough is supposed to have original magic mojo?
I personally liked the ground, & polished uniform dimension A2, A5, A8 bar Magnets.
But, then I've never been a stickler for vintage. More of a stickler for tone.
Ditto what Pepe said on magnetizing bar magnets uniformly with NEOs.
If your Magnets come all magnetized, stuck together in a cube, leave them that way until you need to use them.
GL everyone!
T

[glaze]

Unless you own a industrial-type, zap magnetizer, getting bar mags unmagnetized is not such a good idea.

The only alnico type that can be charged to full-saturation using the most potent (N52) Neo mags is A3.

What is the best way to get a lower gauss alnico bar magnet? I have not spent the time charging alnico with Neo magnets yet to see the results of gauss long term. I appreciate you steering me in the right direction.

I have read Gibson charged magnets in a block which resulted in magnets not fully charged or saturated.

[J M Fahey]

Just what big tee said will work.

Alnico is a relatively soft magnetic material (opposite to ceramic), remember some even come with keeper bars so they are somewhat isolated from external fields, because they are "lossy", every tine they get too close to another magnet, pulling them out causes someloss.

So leaving them in a bunch inside a bucket or whatever is almost guaranteed to weaken the one you pull from that mess

I´m not a pickup winder but make speakers and own big magnetizers, every now and then I have to help a friend who disassembled some alnico speaker magnet for cleaning or recentering and "now speaker is weak and lost definition" ...meaning magnetism weakened a lot and needs recharging.
Same thing.

[LtKojak]

What is the best way to get a lower gauss alnico bar magnet?.

The best is buying different alnico grades. And no, I'm NOT kidding. The procedure is is normally use another bar of different grade, depending on how much you wanna lower the charge... which I wouldn't go over 30% without risking the magnetic field integrity in time. Also, do you own a gaussmeter to check if the charge and or the degaussing of the bar is even? I guess you don't, isn't it?

Why are you so oriented in degaussing? You design your p'up considering a fully-charged magnet. Degaussing is very rarely used in practice, and in most cases it's an in extremis procedure because you find yourself temporarily out of stock of the mag you need, so you're forced to improvise because the customer NEEDS the p'up YESTERDAY.

To be able to run, first you need to learn how to properly walk. I'm sorry if I sound condescending, but due to the line of questioning, it's obvious to me that you're over your head. If it's not the case, I apologize in advance.

[glaze]

big_teee


After reading how good Magnetic Hold magnets sound in several posts from you, I did finally place an order with Magnetic Hold for A2 and A5 Alnico bar magnets. They were polished, charged and looked great. I do have a nice gauss meter but I have not measured them yet.

I have read about the $34.00 USA made unpolished Throbak bar magnets. That is not practical for winders trying to make a $100.00 pickup, but they get great reviews from people who have bought them. Other famous pickup makers are not trying to sell the US made alnico magnets they use.

No source to buy US made unpolished alnico bar magnets for a good price in low quantities that are close to the vintage Gibson magnets?

[big_teee]

I liked the MH magnets, and I hope they don't disappoint.
I don't try to sell anyones product, and I don't say what magnet brands I dislike.
GL,
T

[glaze]

The best is buying different alnico grades. And no, I'm NOT kidding. The procedure is is normally use another bar of different grade, depending on how much you wanna lower the charge... which I wouldn't go over 30% without risking the magnetic field integrity in time. Also, do you own a gaussmeter to check if the charge and or the degaussing of the bar is even? I guess you don't, isn't it?

Why are you so oriented in degaussing? You design your p'up considering a fully-charged magnet. Degaussing is very rarely used in practice, and in most cases it's an in extremis procedure because you find yourself temporarily out of stock of the mag you need, so you're forced to improvise because the customer NEEDS the p'up YESTERDAY.

To be able to run, first you need to learn how to properly walk. I'm sorry if I sound condescending, but due to the line of questioning, it's obvious to me that you're over your head. If it's not the case, I apologize in advance.

I do own a nice gauss meter. I have used it very little so far. I have not gotten into charging magnets with neo's or ceramic bars much yet, but I do have the Mojotone vice pickup magnetizer. I bought a roll of formvar and a roll of plain enamel wire from MWS industries. I have ordered some pickup supplies from Tone Kraft, Magnetic Hold and StewMac. Just gearing up to start winding vintage style pickups for myself with lower gaussed magnets. Lots of famous pickup makers are using lower gauss magnets. I have zero customers and I do not have a pickup winding business. Right now it is just a hobby for myself.

Last year I attended the Lollar pickup winding class in Arizona and wound a humbucker and a single coil. That was a quantum leap forward for me. All I have really done since then is bought some supplies, read forum posts here and studied some other websites information. It's time to get making some pickups for me...

[Helmholtz]

There are several sources for rough cast unmagnetized alnico bar magnets. Just google.

I also prefer weaker magnets. Gibson magnets from the 50s typically had a surface charge between 400 and 500 Gauss. Rather than degaussing I just magnetize to desired level using my adjustable electromagnetic magnetizer. Using a large enough neo and spacers should also work but will require some trial and error. Magnetize both poles separately. I do not recommend using neos in a vise as this typically results in uneven magnetization.

[glaze]

There are several sources for rough cast unmagnetized alnico bar magnets. Just google.

I also prefer weaker magnets. Gibson magnets from the 50s typically had a surface charge between 400 and 500 Gauss. Rather than degaussing I just magnetize to desired level using my adjustable electromagnetic magnetizer. Using a large enough neo and spacers should also work but will require some trial and error. Magnetize both poles separately. I do not recommend using neos in a vise as this typically results in uneven magnetization.

Helmholtz

Great information! Thank you. I am going to try it. You are the second source of information I have seen today that has stated charging magnets in a vice with neo magnets glued to it does result in uneven magnetization as you slide the magnets you are trying to charge sideways through the vice.

If I was able to charge an uncharged alnico A5 or A2 bar magnet right at 500 gauss with neo's and spacers, what would the gauss typically settle down to over time and stay stable?

[Helmholtz]

what would the gauss typically settle down to over time and stay stable?

Apart from a few % drop in the first minutes after magnetization the magnets will be stable (like fully magnetized). Just avoid proximity to other magnets and do not attach them to and slide along ferromagnetic (steel) materials.

[glaze]

Apart from a few % drop in the first minutes after magnetization the magnets will be stable (like fully magnetized). Just avoid proximity to other magnets and do not attach them to and slide along ferromagnetic (steel) materials.

Now I feel confident that I can achieve close to a certain gauss level I want, have a better way to achieve even magnetization and it will be stable. Thanks for everyone's input. Time for me to start experimenting with magnets.