Need basic construction details to build storage container with flux shielding for small magnets.

[ToddB66]

Need basic construction details to build storage container with flux shielding for small magnets.

Creating a generator environment also should weaken the field-strenght
because the magnetical field-lines then must interact with the electrons
inside of the copper-coils.

But I guess the most effective solution is to shortcut it with a
second magnet of the same shape and size. plus to minus and minus to plus.

btw. some scientists claim that the spin of the electrons creates the magnetism.
If thats right if would be some very special centrifugal-powers which creates
special force-lines inside of the time-space continuum. I find it still fascinating
and wikipedia is far away from explaining how magnetism really works and why it
can attract almost magically distant stuff. Electrostatic magnetism also is interesting.
A heavy mountain-thunderstorm can make the hairs going wild into direction sky.

Funfinder,

Thanks.....interesting ideas!

ToddB66

[ToddB66]

Before you put the magnets anywhere near the metal pipe test to see what influence just the pipe by itself will have on the compass
as its oil filled it will be a little slower to react, even a steel bottle cap or a AA battery will skew a compass.

Thanks 6666 ! That's a good suggestion.

ToddB66

[ToddB66]

Need basic construction details to build storage container with flux shielding for small magnets.

[QUOTE=Koala;218655]Big strong magnets normally don't cause any problems. I have a large guitar amp with a very large ceramic magnet in the same room as my electronics as well as some neodymium magnets stuck to the front of a meta self that holds my computer. if you make cabinet out of steel I don't see how you can test it easily. A compass sill be attracted to it even without any magnets in it. The strong field is fairly close to the magnet. You could put them in the centre of a polystyrene cube inside a metal filing cabinet.[/QUOTE]

Koala,

Thanks for your comments !

In your example I colored blue above, what affect does polystyrene have on magnetic field lines of flux ? Does polystyrene absorb and become saturated with magnetic field, causing the field to shortcut to the opposite pole rather than flow through the polystyrene unimpeded ?
Or is it's purpose merely as a spacer to keep the magnets in place and away from the sides of the metal filing cabinet ?

By the way, did you read and understand the information I provided via hyperlinked website addresses in this thread before replying ?

ToddB66

[moodz]

... you probably need a Flux Capacitor also if you are worried about polystyrene absorbing magnetic fields. :-)

[ToddB66]

Need basic construction details to build storage container with flux shielding for small magnets.

Hi Todd,

This might seem a stupid question, but (if the magnetism is a problem) why don't you simply build the container out of something non-magnetic?
What are you wanting to store in it?

Qiaozhi,

Questions aren't stupid, but might be lacking information.

Magnetic field shielding designs utilizing non-magnetic material would be more difficult to make and expensive for my application.

I'm planning on storing (4) small "static" magnets (not "electromagnets"), size 1.875" L x .875 W x .375" H.

Whenever I decide to do a science project, I'm equally interested in gaining knowledge as I am in building and using the
thing of interest. Also, since I'm not rich, project expense is always foremost.

Thanks for your interest !

ToddB66

[Qiaozhi]

Qiaozhi,

Questions aren't stupid, but might be lacking information.

Magnetic field shielding designs utilizing non-magnetic material would be more difficult to make and expensive for my application.

I'm planning on storing (4) small "static" magnets (not "electromagnets"), size 1.875" L x .875 W x .375" H.

Whenever I decide to do a science project, I'm equally interested in gaining knowledge as I am in building and using the
thing of interest. Also, since I'm not rich, project expense is always foremost.

Thanks for your interest !

ToddB66

OK - I failed to understand why you would want to build a storage container out of magnets if the magnetism was a problem. Now I see that you want to use it to store magnets, and the requirement is to cancel the magnetic field of the stored magnets so that they don't affect anything outside the container. Personally, I simply put them in a normal non-magnetic container, and place it up on a high shelf out of the way.

[Ferric Toes]

Before you put the magnets anywhere near the metal pipe test to see what influence just the pipe by itself will have on the compass
as its oil filled it will be a little slower to react, even a steel bottle cap or a AA battery will skew a compass.

Yes, the pipe itself will almost certainly be magnetised. When iron or steel is drawn in a foundry is acquires remanent magnetism when it cools from red heat, to below its curie point, due to the earth's magnetic field.
The best simple test for remanent magnetism is repulsion, not attraction. If you find that a compass needle is repelled from any part of your pipe container, then it is magnetised.

I would think that putting the magnets all stuck together NSNS in a polythene bag which is then put in the middle of a container of iron filings, ferrite, or magnetite powder, would be as good as you can get.
.................................................. ..........................SNSN

Eric.

[ToddB66]

Need basic construction details to build storage container with flux shielding for small magnets.

All you need to do is put the magnets in any type of big enough box to have a physical separation from any electronic equipment and those evil magnetic lines of force , use a compass to test.
If you want to see the lines of force just use iron fileings and a piece of paper.

Hi 6666

Thanks for your suggestions !

I'm age 75, fully retired and living with my wife in a small apartment with limited space on shelves for storing anything "big enough" as you say. So the container for my magnets must be small.

The idea (of using black iron or steel pipe with wall thickness sufficient to provide enough permeability to induce the major portion of flux field from my magnets to use the pipe wall as a conduit or "shortcut" to the opposite magnet poles. ) was generated from the website addresses in my post #8. This idea seems workable and economical to me and is fully outlined in my post #12.

As for seeing the magnetic lines of force, I do have a jar of tiny iron particles that I got from an auto garage where they were re-facing disc brakes and saved them for a hobby that never came to fruition. So I might try that experiment sometime, but initially I'll be using a compass for evaluating my prototype magnetic flux shield storage container.

If you have any extra luck, I will probably need it !

ToddB66

[moodz]

..if you seriously want magnetic shielding then you need Mu Metal https://en.wikipedia.org/wiki/Mu-metal ... the pipe you are proposing will gradually become magnetised itself. Have you considered throwing the magnets away .. storage problem solved.

[Davor]

Davor,

Assume you're joking, Ha!, Ha!

ToddB66

Actually - no. Superconductors are the only substance that by their nature shield magnetic fields. I did not say they are practical solution, but they work as advertised.
Ever seen those levitating magnets? There you have it.

[ToddB66]

Ferric Toes,

I'll try the idea you put forth in the last paragraph of post #22 !

Thanks,
ToddB66

[ToddB66]

..if you seriously want magnetic shielding then you need Mu Metal https://en.wikipedia.org/wiki/Mu-metal ... the pipe you are proposing will gradually become magnetised itself. Have you considered throwing the magnets away .. storage problem solved.

moodz,

I can't afford ultimate solutions like Mu Metal or Superconductors.

So I'll just have to go with a design that simply reduces the outflow of Magnetic lines of force from the walls of my container and thus minimizing the magnetic affect on other items in the surrounding area. Hopefully, this will reduce the overall strength of escaping field, hence preventing any damaging affects to other items stored near the magnet container.

I realize the possible shortcomings of the pipe idea, but believe it offers some advantage over just setting the magnets naked between two pine 2x4's on a shelf.

Another thought: could the escaping field strength increase over time, or would it more likely remain steady owing to the magnets inside the container having no inherent ability to increase their own strength (without external influence of course)??

Throwing the magnets away would terminate the fun of learning and experimenting !

Thanks for your inputs !

ToddB66

[Qiaozhi]

Actually - no. Superconductors are the only substance that by their nature shield magnetic fields. I did not say they are practical solution, but they work as advertised.
Ever seen those levitating magnets? There you have it.

It's called the Meissner effect -> https://en.wikipedia.org/wiki/Meissner_effect

[Ferric Toes]

Hi Todd,
Looking through this thread, I do wonder why you want to go to these lengths to shield, what are in fact, very small magnets. Generally speaking, modern magnet materials do not lose their strength over time and the external static field poses no danger to other electronic or mechanical apparatus, provided a few simple precautions are taken. e.g. do not place them in close proximity to hard drives, magnetic recording tape, credit cards, steel tools, wrist watches etc. There is absolutely no health risk from static magnetic fields. After all, we live on a very large magnet.

Another thing to bear in mind is that for every doubling of distance from a magnet the field strength drops by a factor of 8, so you haven't got to go very far out for the field to be negligible.

My workshop and house have many magnets, some quite powerful. I have two loudspeakers with flux density in the gap of 20,000 gauss (2.0 Teslas). They have a leakage field that I can just detect at 1ft with a compass. A spherical neodymium magnet 20mm diameter and which is pretty powerful, again only just moves a compass at 1.5ft distance. Provided you keep magnets under control and away from the sensitive things mentioned above, they are absolutely benign.

Eric.

[ToddB66]

Eric,

Thanks for your very interesting and informative post (#29). I copied that one for future reference !

I tend to be "bulldogish" when setting out to do something. In this case, I just want to mess around with the pipe thing and see what affect it has on a compass compared to magnets in the open air (no containment). Being fully retired, I have extra time and am in no hurry.

ToddB66