Moldable Iron Powder

A long-term back-burner project just got my attention when I found out that Home Depot sells magnetic paint.

The project is a levitating globe thingie, designed as a control systems trainer that lets the student program the control rules in C and see how different control strategies lead to different sorts of system performance.

The paint got me thinking -- if they can make latex paint with iron powder in it, can I buy some sort of plastic resin with iron powder in it and make my own custom magnetics on the cheap?

So: does anyone know of an iron-powder/epoxy (or whatever) mix out there that you can buy, or an iron powder material that you can mix with your own resin to mold soft magnetic materials out of?

I'm looking to build some cores, and maybe have some made at a low volume if the prototypes work. I do _not_ need super high permeability -- the air gap in this is so big that according to the FEA program I'm using there's not much difference between core material with a relative permeability in the hundreds vs. iron (with relative permeability in the thousands).

Thanks.

Reply to
Tim Wescott
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Interesting! What is it called, and is there a web reference?

Reply to
PeterD

Don't know about the power, but I've used these people for sample cores. Fast service and good product. They might be able to find you some powder.

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Reply to
Jim Stewart

Searching on "magnetic paint" on the Home Depot or Rust-Oleum sites should get you there.

Reply to
Tim Wescott

Hi Tim, There are a lot of iron filled epoxies out there. Two names that come to mind immediately are Moglice and Devcon. I recall Dave Trumper at MIT had a nice mag-lev demo that used a photocell as feedback.

Reply to
jeff

How about a ping-pong ball into a chemical silvering mirror solution and then electroplate iron onto it in a simple ferrous plating bath?

Yes. Although the raw material when dry requires a bit of careful handling preferably in an inert atmosphere. Finely divided iron powder intended for magnetic crack detection is usually supplied as a suspension mixed in kerosene. In the air as a dust it can be pyrophoric.

It is fun to paint some on a magnetic card strip you no longer need.

You might be better off with finely ground magnetite. That is easier to handle and doesn't go woof. This stuff is in vogue these days for fancy magnetoresponsive goops in various esoteric devices. You can make it do some of the T2 type flow then rigid things with a bit of effort - except it is dirty black gunge and gets everywhere instead of a nice mirror finish like in the movie... and a bit fanciful in some articles by the proponents of the technology. eg

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Someone like Alfa or an NDT specialist supplier will sell you the stuff but whether you will think the price is reasonable is harder to answer.

Regards, Martin Brown

Reply to
Martin Brown

Thanks Jeff. That gave me the keywords I needed.

Goodness but it's expensive stuff, at least from McMaster. Gotta think about this again, maybe.

Reply to
Tim Wescott

It's either soft iron, or it needs a strong field to polarize it. How is it used? (IIRC, the permeability of ceramic magnets id low, so they support large gaps too.)

Jerry

Reply to
Jerry Avins

From what I found searching, it's soft. that is, magnets are attracted to it, but it's not attractive on its own.

Jerry

Reply to
Jerry Avins

Right. I'm looking for an armature material for an oddball electromagnet

-- big, light (well, relatively), and capable of supporting a significant AC component without wasting it all as heat.

Reply to
Tim Wescott

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nothing came up with the suggested search terms however.

Reply to
PeterD

Fuck you.

Gunner

"Aren't cats Libertarian? They just want to be left alone. I think our dog is a Democrat, as he is always looking for a handout" Unknown Usnet Poster

Heh, heh, I'm pretty sure my dog is a liberal - he has no balls. Keyton

Reply to
Gunner Asch

Might try picking these up, too:

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?sequence=1 PDF files worth reading. (Found them using David's name, above.)

Jon

Reply to
Jon Kirwan

Look for sintered metal in a magnetic material. I think some magnets are made with sintered iron.

Reply to
Bill McKee

I wish this had come up 5 months ago, when I was taking down Ceromet/MPP in Anaheim, California.

I could have gotten you guys a few thousand pounds of iron powder for free.

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If you want a few pounds..maybe I can get it from another company if I ask nice and they want a service call.....

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Gunner

"Aren't cats Libertarian? They just want to be left alone. I think our dog is a Democrat, as he is always looking for a handout" Unknown Usnet Poster

Heh, heh, I'm pretty sure my dog is a liberal - he has no balls. Keyton

Reply to
Gunner Asch

Hell, NO! They're clearly liberals. They lollygag around the house expecting their human servants to deliver pre-chewed food to their face and schlep away their shit, while they mutilate the furniture, piss all over everything, and sneer at you.

Hope This Helps! Rich

Reply to
Richard the Dreaded Libertaria

:LOL..

Ill have to change that sig..you make sense.

Gunner

"Aren't cats Libertarian? They just want to be left alone. I think our dog is a Democrat, as he is always looking for a handout" Unknown Usnet Poster

Heh, heh, I'm pretty sure my dog is a liberal - he has no balls. Keyton

Reply to
Gunner Asch

Um, better hurry up! ;-)

Cheers! Rich

Reply to
Richard the Dreaded Libertaria

Cat's aren't liberals. Cats just recall when they worshipped as gods. Which they still believe was only right and proper. I'd say today, they're more absolute monarchists. And the only ones who matter are other members of the aristocracy. But I still like the fuzz balls.

- pyotr filipivich We will drink no whiskey before its nine. It's eight fifty eight. Close enough!

Reply to
pyotr filipivich

As do I.

So the sig stays!

Gunner, with Fughead the kitten, curled up in his lap.

"Aren't cats Libertarian? They just want to be left alone. I think our dog is a Democrat, as he is always looking for a handout" Unknown Usnet Poster

Heh, heh, I'm pretty sure my dog is a liberal - he has no balls. Keyton

Reply to
Gunner Asch

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