magnetizing bars w/ stew mac magnets

[Joe Gwinn]

I don't think it will hurt you, though it has been found that using electric blankets is a bad thing because of the magnetic field, and people who live under high tension wire towers seem to have higher incidence of leukemia.

This was from a 1989 book by Brodeur titled "Currents of Death", which argued that 60 Hz elecromagnetic fields from the power system caused cancer. None of this is true, and even if it were true the only solution (rebuild the entire north american power system and all appliances) flunks cost benefit analysis.

None of this is true: The National Science Foundation (?) did a study and refuted each and every of the claims. The report should be on their website, but I couldn't find it. May be too old. Or it may have been a similarly named organization that issued the report I'm remembering. The EPA, NIOSH, et al, also did studies and came to the same conclusion. Which is why there were no changes made to the power system and the issue died down.

The part about high tension wires and leukemia is a classic case of confounding correlation and causation, coupled with selection bias. One of the best established correlations in Epidemiology is that between health and income - richer people have better health than poorer people. (There are many arguments as to why this is so.) Who lives under high tension lines, richer or poorer? This is a classic case of selection bias, which has invalidated many a study.

Cost benefit analysis: Replacing the north american power system with a shielded equivalent would cost at least a trillion US dollars. If the intent is to improve the general state of health, one could instead spend that money directly on health. There could be EMT teams on every street corner, waiting for someone to have a problem, etc. Medical care could be free to all. The number of lives saved would vastly exceed that due to replacing the power system et al, even if one accepts Brodeur's thesis and estimates. Which the NSF et al did not.

It was quite the fight. Here is one pointer: http://www.ewh.ieee.org/soc/embs/comar/brodeur.htm.

Back to pickups. The fields over a guitar pickup vastly exceed those that Brodeur worries about, so soon there will be a new occupational hazard of guitar players, starting in the fingers ....

[David Schwab]

Well that's good to know!

There are some high tension wires running past an upper middle class area here in Northern NJ.

People have planted vegetable gardens in the space under them.

[Possum]

...

Be aware that those "scientific studies" are often politically funded to come to the "right" conclusions which always benefit big corporations. The Bush era this kind of thing got totally out of control enough that it became real noticeable, and some scientists lost their jobs by speaking out against it. If you're reading up about such things it'd be a better idea to read studies not done in the US where gigantic power companies have their finger in what you read. Its like the cell phone thing, I don't think anyone over here has officially said they are damaging but in European countries they have issued warnings and done enough research that shows holding a microwave transmitter to your brain for hours and and hours a week is damaging to the nervous system and implicated in brain tumors. I would never buy a house near a huge power line or a microwave transmitter tower. I do use a magnetizer I have a cast iron chastity belt on when I do, he he....

[Clint Searcy]

I'm just glad we're living in the Hopen'Change era now. No more of that sillyness anymore. Now all I have to figure out is my taxes. Do I still pay them to the IRS or do I make the check out to AIG directly? Or do I just skip paying taxes all together and apply for a cabnit position? It's all so confusing these days.


I have found that using a thick neo magnet charges alnico better. Thin magnets don't give a full charge.

[Bruce Johnson]

Hmmmmmm....... Not to be a weenie, but I wonder if there are any detrimental long-term effects as a byproduct of regularly sticking your hands into that kind of magnetic field?

You may already have symptoms of acute magnetaphobia.

[David King]

I'm having a lot of trouble magnetizing a split coil jazz bass humbucker. I do one half then flip to do the other by which time the first half is nearly dead again. I need a way to focus the field or I'll need to bust the two coils apart which I'd rather not have to do since I'd like to be able to mess around with various gauss levels in situ. My charger is a 1/2" x 1 x 2" neo mounted on a 1 ton arbor press. Would a pair of steel cones that meet over each pole piece keep the field in line?

[Joe Gwinn]

I'm having a lot of trouble magnetizing a split coil jazz bass humbucker. I do one half then flip to do the other by which time the first half is nearly dead again. I need a way to focus the field or I'll need to bust the two coils apart which I'd rather not have to do since I'd like to be able to mess around with various gauss levels in situ. My charger is a 1/2" x 1 x 2" neo mounted on a 1 ton arbor press. Would a pair of steel cones that meet over each pole piece keep the field in line?

Yes, although I'd use two steel bars to focus the magnetic field through one row of magnets at a time.

[Clint Searcy]

I'm having a lot of trouble magnetizing a split coil jazz bass humbucker. I do one half then flip to do the other by which time the first half is nearly dead again. I need a way to focus the field or I'll need to bust the two coils apart which I'd rather not have to do since I'd like to be able to mess around with various gauss levels in situ. My charger is a 1/2" x 1 x 2" neo mounted on a 1 ton arbor press. Would a pair of steel cones that meet over each pole piece keep the field in line?

I make a pickup like that for one of my builders. I just magnitize them before I build the pickup anymore. Too tricky the other way.

[Seth Leigh]

Arg, I'm trying to remember the name of the company, but my wife got invited to, and dragged me along to, a presentation (to a fairly large group of people too) by a multi-level marketing company that claimed that exposing the human body to magnetic fields had miraculous health results. It was all just so much pseudo-techno-babble bullcrap, but a lot of naive people were taken in by it. I know a family that spent a lot of money buying magnetic insoles, magnetic jewelry, pads for their beds containing magnets, magnetic water treatment machines, and so forth.

At one point they had this battery-powered "magnetic energy meter" (my words, not theirs, I don't remember what they called it) that they would wave in front of their products, causing light on the device to light up. This was evidence of all of the magnetic "energy" their products were giving off. So I raised my hand and said I could build a device like that with a simple coil of wire, a transistor, a battery, and an LED. All it would prove was that their products contained magnets, not that they emitted "energy" into peoples' bodies or anything like that.

Playing the skeptic did not endear me to that crowd, neither the audience nor the company scheisters doing the presentation.

It's almost as if people wanted to be lied to, so long as the lies were pleasant ones.

[David Schwab]

Magnets do affect the body though. There was some research done where they blind folded people for about 7 days to see how their senses would change. The idea is that after a while the parts of the brain that handle vision remap to do other things. They found that when they passed strong magnets close to their heads the test subjects would see shapes and lights.

[Joe Gwinn]

Magnets do affect the body though. There was some research done where they blind folded people for about 7 days to see how their senses would change. The idea is that after a while the parts of the brain that handle vision remap to do other things. They found that when they passed strong magnets close to their heads the test subjects would see shapes and lights.

http://en.wikipedia.org/wiki/Transcr...ic_stimulation

[Mark Hammer]

Well, whether they do harmful things to the body or not is one thing. They would/could most certainly wreak havoc in the post office!! How on earth do people ship neodymium magnets of that size? Does it have to be suspended in a cardboard frame with 6" of space on all sides, or something like that?

[David Schwab]

Well, whether they do harmful things to the body or not is one thing. They would/could most certainly wreak havoc in the post office!! How on earth do people ship neodymium magnets of that size? Does it have to be suspended in a cardboard frame with 6" of space on all sides, or something like that?

When I get the smaller ones they have each group of them together and wrapped in a dense foam type padding, and then they are in a larger box filled with styrofoam peanuts. So they leave about 3 inches around the magnets.

I'd imagine the bigger the magnets the larger the box.

[Joe Gwinn]

When I get the smaller ones they have each group of them together and wrapped in a dense foam type padding, and then they are in a larger box filled with styrofoam peanuts. So they leave about 3 inches around the magnets.

I'd imagine the bigger the magnets the larger the box.

Dipole fields (like the N and S poles of a magnet) fall off very quickly, with the inverse cube of distance.

If you stick two magnets together, you get a quadrupole field, which falls off as the inverse fifth power of distance, which is very fast.

General rule is that a N-pole field falls off as the inverse (N+1)th power of distance. So a brick of magnets may have very little external field.

[EFK]

Well I guess I get the weenie of the year award for mutating the original thread into the "oh my god we're all gong to die of magnetized blood" concern. Really guys, some interesting information. Thank you! Insofar as shipping, I wondered myself how my 'bricks' were going to arrive and they were in a pretty good-sized box with considerable space around the magnets. I unpacked it here in the house to inspect them but got distracted before I could head back down to the shop, so I threw the box in the woodstove and stuck them - two 3X1X1/2 neos - in my pocket. Then, my wife needed help with something and as I wasn't thinking about the magnets, I passed a little too close to the washing machine: CLANG! Sounded like someone hit the side of it with a club. Is that a brick of magnets in your pocket or are you just happy to see me? My first experience with neos!