Instructables
Picture of magnetic silly putty
Thinking Putty (also known as Silly Putty) is a silicone polymer children's toy. Silly putty is fun because it has some unique properties: it is viscoelastic, meaning it can be stretched and shaped and mashed back together again; and as its apparent viscosity increases directly with respect to the amount of force applied (read: it can be torn or shattered with impact). Silly putty is a non-Newtonian viscoelastic polymer, better characterized as a dilatant fluid. Also, it bounces.

Ok, enough science. I'm sure we've all played with Thinking Putty in our youth, but how about magnetic silly putty?

By adding a ferrous component to an already wacky toy we can keep all characteristics of the original putty, but now have the additional dimension of magnetism! I've seen magnetic thinking putty for sale on other websites, but I'll show you how you can make your own for a fraction of the price and in about 20 minutes.

Enough talk, let's make some magnetic putty!
 
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Step 1: Tools + materials

Picture of tools + materials
tools:
  • disposable gloves (latex or other)
  • disposable face mask
  • disposable work area (paper plate)
materials:

The secret ingredient that makes the putty magnetic is an iron oxide powder, which is ferric (magnetic). Ferric iron oxide is a fine powder used as black pigment and can be found at art stores. If your local artist supply store doesn't carry it, you can always purchase it online.

Step 2: Prepare putty

Picture of prepare putty
Start by clearing a space to work, make sure it is well ventilated. Iron oxide powder is very fine and inhaling it is probably not such a good idea. Put on your gloves and face mask before you begin.

Open the thinking putty and remove from the container. Work the putty in your hands a little to warm it up, then stretch it out like a sheet and lay it on your disposable work surface (sheet of paper or paper plate).
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Holy cow. Great project for kids...

Really cool project. Thanks for sharing this

Fishyfish1237 months ago
I once got some putty stuck on my pants and I washed it and it but it stayed in. Them I use some goo-gone. It it orange stuff you can buy and it is a miracle. If you ever get any goo stuck on something, no matter what the bottle says, USE IT!
LP21 year ago
Thank you !
This looks a lot safer than the Kerosene and chemical acid tutorial on you tube.
LinuxPusher.
i have a question is the stuff you get off the ground when you place a magnet in the dirt the same as Ferric iron oxide and even if it isn't, if you were to collect enough of it and mix it with the putty would it work the same? (possabily with out turning it black?)
mikeasaurus (author)  cbortizfield1 year ago
When you sweep a magnet over dirt you are likely picking up rust, which is exactly what iron oxide is. This should work, but a powdered iron oxide will produce more favourable results, as the consistancy will be uniform, and you won't have any potential sharp bits from an unknown substance that you collected from the ground.
Laral1 year ago
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mikeasaurus (author)  Laral1 year ago
Thanks for sharing your version, the pictures look amazing!
Enjoy the digital patch and the 3-month Pro Membership
Wow, thanks! Did you also see the video? I tried to delete the above post and redo it with the video embedded this time. See below.
That is uber sweet looking!
Laral1 year ago
I made a batch of this with some putty and some black iron oxide (Fe3O4) I had on hand and it is pretty cool. I left a blob of it on a glass tabletop with a couple of strong neodymium magnets under the glass and it morphed into some kind of alien-looking black magnetic 'fungus'. :)

http://img24.imageshack.us/img24/195/xrop.png

http://img708.imageshack.us/img708/5794/dmsk.jpg

http://img163.imageshack.us/img163/55/zo5t.jpg

I thought it would just flatten out, but it turns out that the iron oxide particles try to align themselves to the magnetic field, impeded by a viscous fluid, so they form random "regions". Pretty neat.

Some commercial putty I have behaves differently.

http://img856.imageshack.us/img856/2517/ztzu.jpg

It has magnetized powder in it so the particles are able to align themselves more uniformly despite the viscous fluid. Interesting.

BTW the putty I made is too stiff, so I later added some silicone oil to it to soften it. I posted on this in the other Instructable:

http://www.instructables.com/id/Making-Better-Magnetic-Ferrous-Silly-putty-with/?comments=all#CPFRG5ZHKTZMYEP

Here's a video with a side-by-side comparison:

http://www.youtube.com/watch?v=uK9o-arYvKg

DSCF0398_cr.pngDSCF0400_cr.jpgDSCF0404_cr.jpgDSCF0433_cr.jpg
Wouldn't it be completely amazing to crush neodymium magnets into a powder, and mix the silly putty with a combination of that and graphite? You should come out with a conductive and highly magnetic putty.

Real world uses for a substance like this...GO!
Be careful. Neodymium magnets are extremely brittle which means they are likely to shatter violently if you try crushing them. The pieces also have very sharp edges (I know that from experience!). To make matters worse, the powder produced is highly reductive and can oxidise so rapidly that it ignites.


You also need to bear in mind that if the attraction between the magnetic particles and the surface you put the putty on is greater than the adhesive properties of the putty itself then the particles will be left behind and you'll eventually end up with magnetic powder all over your house.


As for they idea of the putty becoming conductive with the addition of conductive powders, there would need to be a continuous path of conductive particles from one terminal to the other. I doubt that there would be enough putty in such a mixture to retain its putty properties.


Sorry to be such a downer.
Downer number two: It won't work anyway.

A magnet is only magnetic because all the microscopic magnetic domains are all lined up the same way.

If you crushed a magnet into powder and mixed it in, there would be no overall magnetic effect, because all the magnetic domains would be randomly aligned, and would cancel each other out.

The only effective "magnetic" powder you can mix in must be "paramagnetic", that is, attracted by magnet, but not a magnet itself.

(Yoda voice:)  No sorry !  In science class, more attention you must pay, young Smilewalker !
Absolutely wrong! Magnetic powder is polarized by a magnet. Inside of putty the polarization keeps for quite a while. This is NOT the case with just iron oxide or filings.
"Magnetic powder" ? What magnetic powder ?
The powder of a crushed magnet will behave as I have said.

If you magnetised a ferromagnetic powder _after_ mixing it into the putty, it would create a magnet, but the magnetic domains would start cancelling each other out as soon as the putty was re-moulded into a different shape.

May I suggest you read up on "Magnetism" on Wikipedia ?
And do the experiment to test your theory ?

(Repeat Yoda comment.)
No need to read up on magnetism. I did that in my E&M course in college. I am talking from personal experience. The magnetic Thinking Putty contains powdered magnetized particles and behaves as I have already described. Watch this video for a dramatic demonstration of the difference between FERROmagnetic powder and MAGNET(ic) powder. Really awesome difference. I assume this is what TP contains.



http://www.youtube.com/watch?v=ZazPBWQexgk
Magnetic Thinking putty DOES NOT contain magnetised particles.

From: http://www.puttyworld.com:

"When Super Magnetic Thinking Putty is stretched, molded, or shaped, the putty has no magnetic charge and behaves like any other Thinking Putty. However, in the presence of a magnetic field, its magnetic forces begin to align. Suddenly, a truly Super Magnetic Thinking Putty is created that will attract to one magnetic pole and repel from the other."

So it is paramagnetic, NOT ferromagnetic.

So you really do need to read up on magnetism.   (And on Thinking Putty,)

The video shows the behaviour ONLY of free magnetic particles.  
They will not behave like that when randomly mixed into a putty.  
Do the experiment for yourself if you still don't believe me.

Magnetic Thinking Putty will demonstrate NO magnetic behaviour at all without the presence of an actual magnet.
"Magnetic Thinking putty DOES NOT contain magnetised particles."

So you know this for a fact? How do you know?

"From: http://www.puttyworld.com:"

You should link to the exact page where you found this quote.

http://www.puttyworld.com/midnightcolors.html

"When Super Magnetic Thinking Putty is stretched, molded, or shaped, the putty has no magnetic charge and behaves like any other Thinking Putty. However, in the presence of a magnetic field, its magnetic forces begin to align. Suddenly, a truly Super Magnetic Thinking Putty is created that will attract to one magnetic pole and repel from the other."

"So it is paramagnetic, NOT ferromagnetic."

Well, first of all, you need to know the definition of 'paramagnetic'.

http://www.ndt-ed.org/EducationResources/CommunityCollege/MagParticle/Physics/MagneticMatls.htm

"Paramagnetic materials have a small, positive susceptibility to magnetic fields. These materials are slightly attracted by a magnetic field and the material does not retain the magnetic properties when the external field is removed. .. Paramagnetic materials include magnesium, molybdenum, lithium, and tantalum."

So your conclusion is erroneous since the putty DOES retain a considerable amount of residual magnetization after being exposed to a magnetic field. That's why it attracts paperclips in the video. I have some of this putty and it retains a fairly strong magnetic field. It is easily repelled by the opposite pole that it was magnetized with. That rules out paramagnetic material.

"Ferromagnetic materials have a large, positive susceptibility to an external magnetic field. They exhibit a strong attraction to magnetic fields and are able to retain their magnetic properties after the external field has been removed. .. When a magnetizing force is applied, the domains become aligned to produce a strong magnetic field within the part."

OK but the residual field after the magnet is removed is negligible. Again, from my personal experience, this DIY putty does not retain any noticeable magnetic field after being in contact with even a very strong neodymium magnet. It exhibits no magnetic polarization. So the only possible conclusion is that there is MAGNETIC, as in magnetized, material in this putty. That's the only way it could exhibit the properties it has.

See Crazy Aarons' comment:

http://www.instructables.com/id/magnetic-silly-putty/?comments=all#CN7GBA4GOOP5C7K

"The first time I added this black pigment to our putty, I noticed, accidentally, that it was attracted to magnets. That is what gave me the idea to create our magnetic putty. The stuff we sell as Strange Attractor or Quicksilver has a few secret ingredients that add considerably more kick.

For example, with Iron Oxide, you can't get the putty to pick up paperclips or repel a magnet when you switch the poles."

The secret ingredient has to be magnet powder.

"So you really do need to read up on magnetism.   (And on Thinking Putty,)"

Before you go making challenging statements like this, in such a disrespectful manner, and posting information that is erroneous, you really should do some online research and then take a course or two in Electricity and Magnetism,  so you know what you are talking about. You clearly haven't done that and have virtually no understanding of the topic.

"The video shows the behaviour ONLY of free magnetic particles. 
They will not behave like that when randomly mixed into a putty. 
Do the experiment for yourself if you still don't believe me."

They behave exactly the same way though the movement of the particles is slowed due to the high viscosity of the putty. And, as I have stated numerous times, I HAVE done the experiment myself. I suggest that, after you do your homework on the subject at hand, you then purchase some of the putty and perform your own experiments. You really can't go telling someone who HAS done the experiments to go do the experiments when they already have and YOU haven't. That's illogical.

"Magnetic Thinking Putty will demonstrate NO magnetic behaviour at all without the presence of an actual magnet."

Actually, AFTER coming in contact with a magnet, the putty is magnetized for a while and behaves like a regular magnet. Again, that is why it can attract paperclips and be repelled by a magnet.
you could have conductivity as long as the voltage were high enough to arc from particle to particle within the putty. even air becomes conductive at a high enough voltage, its just a matter of how much voltage you would need to make that jump. Unfortunately the only magnetism I was ever good with in school was electromagnetism. What can I say? I'm a computer geek, not a physics major.
Seriously?!
You're talking about enough voltage to arc between tiny conductive particles surrounded by a non-conductive medium. Odds are you would get an arc between the terminals without the modified putty. Either way, I wouldn't want to be anywhere near it when you turn the juice on.
Any thing above 3.5 vdc will jump if allowed to. And with enough iron oxide powder it will work with just 1 vdc applied.

Electricity is nothing more then a theory and I dare you say differently.
As an electrician I have seen electricity do some really strange things that cannot be explained by theory alone.

And remember VOLTS do not kill AMPs do.

P.S. I already tried and it will pass 1 vdc. Pretty cool..
Yeah, I can only think that arcing within the putty would put bits of it all over the room.

That could be fun too, though.
A car engine spark plug takes about 20,000 Volts to reliably cross a (fairly clear) air gap of about 1/25 of an inch (1mm).

For BlackFang's putty to conduct, the voltage would need to be sufficient high to cross the sum of all the gaps between the particles, impeded by the insulation of the putty.  Do the math if you want to !

BlackFang, I advise a welder's mask at the very least !

I shall be with psibbald, on the other side of the (steel) door.
Steel be buggered. Glass is an electrical insulator and we could watch the fun.
Can we compromise: Transparent Aluminium ? I've always wanted to try some. It is bulletproof, but I'm not sure about it's conductivity.
I agree it is counter intuitive, but at work I have made use of electrically conductive paints made from silver particles or graphite particles dispersed in a polymeric binder and solvent. There is even a company making a conductive printing ink based on finely divided copper particles. I guess you can get a sufficiently continuous path of connecting particles if they are small enough and of a very high concentration. I would imagine though that at this level of concentration the VE properties of the silly-putty would be lost.
"if the attraction between the magnetic particles and the surface you put the putty on is greater than the adhesive properties of the putty itself then the particles will be left behind and you'll eventually end up with magnetic powder all over your house."

Wouldn't the magnetic powder just move towards itself to form a ball in the center of the putty?

Re the conductivity, there are lots of non particulate conductors, like saltwater, and also you can buy conductive rubber, so it must be possible to do.

I concur on the shattering of the magnets. I have cut myself many times on broken magnets. Strongly magnetic knives are a bad idea.
Laral1 year ago
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mikeasaurus (author)  Laral1 year ago
Looks like the pictures aren't attached to your comment. Can you try again?
I had better luck uploading images from profile.
I tried twice now to include html 'img' links because the uploader here is not working. If it requires java I won't enable it. The images show up fine in the preview but not in the post. Aren't html tags allowed?
amuderick3 years ago
Crazy Aaron of Thinking Putty here. Love this instructable!

The first time I added this black pigment to our putty, I noticed, accidentally, that it was attracted to magnets. That is what gave me the idea to create our magnetic putty. The stuff we sell as Strange Attractor or Quicksilver has a few secret ingredients that add considerably more kick.

For example, with Iron Oxide, you can't get the putty to pick up paperclips or repel a magnet when you switch the poles.

One warning when dissolving magnetic tape for the carbonyl iron powder...the particles are so small that they can travel through the skin and become a tattoo.

Have fun!
I can verify the putty. It is magnetizable so must contain magnetized powder. It holds the magnetization for a long time and repels the opposite pole of the magnet quite strongly.
Quicksilver is another name for mercury, which WILL absorb through the skin and is poisonous. Please do not use names that will confuse kids.

If iron is ingested by a small child in the same quantities as in adult vitamins, or even vitamins for older children, it can be collected in the liver in excessive amounts and can poison the child. Using iron oxide or rust or iron-rich dirt is not non-toxic for any child still young enough to put his fingers in his mouth while playing with this stuff.

Have kids rinse hands when finished playing, or wear the cheapy plastic gloves while playing if you do this activity in a classroom or with children. Always veer on the safe side with kids, that's the Classroom Safety Guideline.

Now that you know how to stay safe, have fun. This idea is great for kids and the kid-in-adults, too.

Valerie Coskrey's Classroom Tools and Ideas has more tips on safety. Come visit me there. Use the Essay List to locate articles.
mikeasaurus (author)  amuderick3 years ago
Thanks Aaron,

Your magnetic putty is some seriously fun stuff, and how you guys manufactured the glass putty I'll never figure out!

Thanks for the kind words, and the interesting tidbit about your Strange Attractor putty.
potrzebie3 years ago
I'm pretty sure that "ferrous" and "ferric" do not mean magnetic. They describe different valence states of iron.

Also, I don't know about electrical current through Silly Putty, but I know you can make electrical circuits from "Play-Doh".

http://courseweb.stthomas.edu/apthomas/SquishyCircuits/BUILDINGCIRCUITS.htm
Hey potrzebie, how's Arthur? LOL! What-me-worry?
ericmcd842 years ago
I wasted $17 today to learn that not any black pigment will work. I even brought the magnet into the art store and tested the pigment which was definitely magnetic, but when mixed with the putty it wasn't anywhere near strong enough to even phase the magnets. The magnets I used are insane too - they have an attraction field of about 3-4". And I can't find Schmincke pigments anywhere locally. I guess I get to go back and find some pigments with serious magnetic attraction. The other huge difference I noticed in mine versus the one shown was that mine was very dry and very hard - the putty shown looks almost like a liquid. I have no clue what I'm doing wrong, but I'm going to blame it on the pigment I bought and try again.

I did learn that ferric pigments are only in the earth-tone range, though - black, brown, yellow, red, and orange. So no blue, green or violet.
alphachem08 on eBay sells black iron oxide (Fe3O4). 1 lb for less than $10. It works well. I had them sieve it. It was hand marked "-200", which I think means #200 mesh (74 microns).
F23O4 Label.JPG
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