Introduction: New Way of Making a Ferrofluid. Costs Less Than 3$!!!

Picture of New Way of Making a Ferrofluid. Costs Less Than 3$!!!

Ferrofluid - a substance that's liquid under normal conditions, but turns solid in the presence of a magnetic field.

I found new way of making home made ferrofluid and I want to share it with you guys.

The advantage of my project is cost. It's way cheaper than all other methods online and it is indeed very simple.

My ferrofluid consist only two inexpensive parts, you only need old record tapes and a bottle of acetone!

Step 1: Materials

Picture of Materials

You will only need ACETONE, record TAPES, cooking OIL and MAGNET.

---500ml/16 fl. oz. Acetone. (1.50$)---
Acetone is high flameable be careful with it. You can get it at department store. It cost around 2$.

---10 music tapes or 4 video tapes. (0.00$)---
Use old music or video records tapes.You can get them virtually in any basement...

---5ml/0.2 fl. oz. Cooking oil. (0.00$)---
Every house has a secret room...The Kitchen...

---1 big strong magnet. (0.50$)---
You can get it from any old speaker in your house. Just take it apart and use it!


Step 2: Prepare Tapes

Picture of Prepare Tapes

The tape itself is actually very simple. It consists of a thin plastic base material, and bonded to this base is a coating of ferric oxide powder. The oxide is normally mixed with a binder to attach it to the plastic, and it also includes some sort of dry lubricant to avoid wearing out the recorder.

Ferric and iron oxides:
Iron oxide (FeO) is the red rust we commonly see. Ferric oxide (Fe2O3) is another oxide of iron. Maghemite or gamma ferric oxide are common names for the substance.

More info how tape work:

We need separate Ferric oxide from plastic tapes. Acetone will melt binder and separate Ferric oxide. But first we need to smash and break tapes!

Step 3: Melt Binder and Separate Fe2O3

Picture of Melt Binder and Separate Fe2O3

Find large enough bowl. Put all tapes in and fill bowl with acetone. Wait few hours. You should close bowl with something to keep acetone from vaporising.

Step 4: Collect Ferric Oxide

Picture of Collect Ferric Oxide

Collecting ferric oxide:
Get a magnet. Roll it with paper or plastic bag (it is needed to separate ferric oxide from a magnet easily). Collect all your Fe2O3. Let ir dry.

Repeat step 3:
If not all oxide has separated from a tape you can repeat procedure with acetone few time to get a better effect.

Step 5: Make a Substance

Picture of Make a Substance

Mix with oil:
For 1ml of ferric oxide you need 1/3ml cooking oil.
Mix it. If it's to viscous fill a drop of water and detergent and mix everything again. It will help oil to mix with oxide.

Step 6: Overview

Picture of Overview

Magnetize ferro fluid:
Don't forget to strongly magnetize your ferro fluid.
Use biger magnets. Large ferrite magnets are better than small strong neodymium magnets.

Bravo! You have made medium quality ferrofluid!


ArfaidaL (author)2017-02-26

500 ml of acetone right? To have a greater effect in stripping off the tape binder, i used 530 ml of acetone. But still, it has no effect. You will only observe the effects in 1-3 weeks or beyond that. Wait for a few hours??? Just Wow!!! How can u possibly post this? To torture others?

Zujus (author)ArfaidaL2017-02-26

You might have had a tape with a different metal coating. What did it say in the package? Also the plastic part might be different too, look for old tapes!

ArfaidaL (author)2017-02-26

Your aim is to make an alternative ferrofluid right? Well, to tell u honestly, this is a waste of time. And not sure if it's work or not. And if it's not going to work as soon as possible, means wasting money also. Why make it difficult? You can make a ferrofluid when u mix glue and iron fillings. I promise, it's not a waste of time. Why don't u try that one?

ArfaidaL (author)2017-02-26

Actually, i followed all the instructions here just like you said. However, i got different outcomes. You can't melt the binder with acetone within just a few hours. It took me a week to notice that binder was gradually losing its color. And not just that, only a small portion of the tape was stripping off. It will take three weeks to fully strip the color of the tape binder. And i observed, as the tape binder was stripping off, no signs of ferric oxide. If you're going to melt the tape binder with acetone, it will just lose its color.

ArfaidaL (author)2017-02-26

how long will it take for the acetone to melt the binder?

Biotele (author)2007-06-14

1)Burn Steel Wool 2)Put in water 3) Wait a couple of days. All the FeOx will turn to powder. 4)Separate the magnetite with a magnet. The trick with ferro fluid is to have very fine powder so it make a suspension called a "colloid". The medium is usually a mixture of oil and kerosene. Maybe if you put the magnetite in a tubler you will get very fine powder.

Zujus (author)Biotele2007-06-14

Thanks I will try to get steel wool and if this will work i involve this to my instructable (with your name of course).

Biotele (author)Zujus2007-06-18

Did I say a couple of days...I meant a couple of weeks. I don't understand the process but burned steel wool maintain its integrity and doesn't fall apart. After soaking in water for a couple of weeks, red rust will appear and the burned steel wool falls apart. I hope someone can explain this and suggest a faster process.

bikerbob2005 (author)Biotele2008-08-30

hot hydrogen perxiod will work faster than water its not nearly as mole stable as water is. as for the steel wool get the super fine type ,dont burn it with fire use a 9 volt battery as fire will give bad contaminants .next week how to centrifuge right guard for the alu oxide

Oh, that sounds interesting -- what do you do with aluminum oxide? Toothpaste and a lot of other things have titanium oxide for whitening, I wonder if you could get much out and do something interesting with that.

flio191 (author)Biotele2008-05-15

i would use one of those fish tank bubblers, so it touches more oxygen... so it oxidizes. or one of those hydroponics air stones... in any case, just get more air on it, and it should rust faster... right?

DanielC23 (author)flio1912015-04-17

Nope....H2O has more O (30%) than "air" which is 78% nitrogen and only 21% oxygen, with traces of water vapor (which has more O than the air it is in! lol!), carbon dioxide/monoxide, argon, ozone and various other trace components, this is why wet iron rusts faster than dry iron exposed only to air.

Just a little common sense applied to a lot of old Star Trek episodes reiterating the percentages of atmospheric gasses in the many "class M planets" (human breathable without respirator assistance) they came across in their "Treks" and putting together the obvious components of water being 2 hydrogen molecules to 1 oxygen, making it 66% H to 33% O rounded down to whole numbers.

However, this is not to say your suggestion is completely without merit, since stirring or agitating the water will expedite the oxidation process for replenishing new O molecules as they combine with the fe molecules.

But the way to REALLY increase the rate is CAREFULLYusing an OXIDIZER, which is anything with the "oxidizer" logo on it, but I would limit that to adding only Hydrogen Peroxide (if you look at it, it tells you what it is,one hydrogen per oxygen, or 1 H for each 1 O making this 50% oxygeninstead of the 30% that water has, and when this reacts with the iron, it will release only oxygen gas, and leave plain water as the byproduct, much safer than the other most common oxidizer found in a household... that I suggest to avoid all togetherwhich is....bleach..., because that releases chlorine gas which is poisonous/toxic!

Peace, Love, and Light!

Zujus (author)flio1912008-05-17

I think it will only work in theory.

beehard44 (author)Zujus2010-03-19

well, the reaction slows down when there is less dissolved O2, cuz O in FeO is oxygen, and where will the iron get the oxygen from oxygen-depleted water? flio has a point there...

twenglish1 (author)Biotele2008-05-17

you can add vinegar to speed up the rusting to a couple hours

twenglish1 (author)twenglish12008-08-30

oh crap i forgot you have to mix bleach and vinegar and put steel wool in and it rusts the whole piece in a couple hours then filter the rust out with a coffee filter

duct tape (author)Biotele2007-07-19

You take steel wool, put a 9-volt to it, and then when the core is glowing red, drop into a bucket of water. this gave me results in 2 nights.

Biotele (author)duct tape2007-07-19

I burned the steel wool over the stove. it took a while to get it all burned. And i had to blow at it. Is the 9 volt battery faster? When the core is glowing red is it transient or does the 9 volt battery maintain a current and glows red for a while? I will have to try it. Thanks.

duct tape (author)Biotele2007-07-19

Basically, you just touch the battery to it and it starts to burn. Then you take the battery away and it keeps burning. If you want it to go faster, you have to blow at it still. Sometimes you will get Fe2O3, sometimes Fe3O4. What do you mean by transient?

Biotele (author)duct tape2007-07-19

that's what I usually do, but it takes two week for the steel wool to disintegrates. It must be the water.

duct tape (author)Biotele2007-07-19

after the steel wool is cooled down, take it out of the water and leave it in the sun.

999592 (author)Biotele2008-12-08


Mr.NHRA (author)Biotele2008-11-18

burn steal wool with a 9 volt?

Darmago (author)2007-06-22

Could you be a little more specific on how you "magnetize" the ferrofluid, I'm a little confused at this point. Also, why does size matter and not strength for magnetizing it?

arlesbad boysb (author)Darmago2016-05-23

bigger magnets make bigger fields ..and are usually stronger out of size im guessing.

last_decoy (author)Darmago2008-07-11

another good substance is to ask mates or uni ("borrow") finished toner cartridges! there is still always at leased a table spoon of toner powder left in them!! (toner is a magnetic ink) mix this into the substance too. it adds to the effect really well. !! dont make it too weak cause it just flops about after the magnet then !!

beehard44 (author)last_decoy2010-03-19

i didn't know that regular toner cartriges use magnetic ink a.k.a. toner...
i thought that a special toner is used for that one...

WJR339007 (author)beehard442015-06-24

It isn't just any toner, it has to be MICR (Magnetic Ink Character Recognition), which is used on checks. You can get a refill bottle for fairly cheap on ebay, and some even come with gloves and an extra top with a "funnel"

200g MICR Refill with gloves and extra top-

This next link has four bottles of different colored MICR Toner, and I'm not completely sure, but this might change the ferrofluid color as long as you use a clear or lightly colored oil (vegetable oil, maybe Canola oil, etc.)-

aristide202 (author)beehard442012-04-04

Me neither , Are you sure that toner is megnetic ? I thught it was som kind of organic. Anyway iron must be just a part of the compound

Zujus (author)last_decoy2008-07-11

Yea, there was popular instructable about that. :)

itsthatsguy (author)Darmago2008-06-27

ok the way he made the ferrofluid is by putting amagnet underneath thats what he means by "magnatize" and you do want a strong magnet but you also want one that covers a big surface area so you get a big affect Cheers

hairyneil (author)2016-04-07


TimothyH49 (author)2016-03-13


ReeceD1 (author)2015-12-23

Nail polish remover is acetone, its pretty benign. However there are a couple issues here first Fe2O3 is red rust, FeO is black. The black FeO is generally whats in ferrofluid but its expensive hence the tapes (great idea). I have been trying VHS instead of cassette (more FeO) but acetone is not eating the plastic. I could purchase some solvent like DMSO but i might as well just buy the FeO then. I tried gasoline no luck, wondering if there is some type of coating on the tapes that needs to be stripped (can't reason why it would be impervious to gasoline) but I was thinking of pre treating in bleach then back in gasoline. Anyone have any experience pulling this stuff from VHS? Maybe the gasoline is just super slow so I could heat it but I am not crazy about that idea for obvious reasons. Any assistance internet?

A.RH (author)2015-11-07

Could I use nail polish remover instead of acetone?

pimmbittyz (author)2015-04-27

pimmbittyz (author)2015-04-27

andytangtsk (author)2014-12-08

Fe2O3 is red rust. Fe3O4 is the thing you made, great i'ble still

grokcore (author)2013-02-21

You can't make nanoparticles out of casette tapes, sorry.
It's neat, but it's not true ferrofluid, it's some kind of ferrite suspension, but you can do something this with rust/iron filings and oil (and a really strong magnet).

grokcore (author)grokcore2013-02-21

Oh - but you can make it though (but expect some nasty nasty fumes)

Ironious (author)grokcore2014-12-05

This is the method I use, but use half the amount of kerosene or else too watery and wont spike.

nro.slm (author)2014-10-17

I've seen commentators on other projects note that cooking oil will go rancid after some time and recommend mineral oil. That's what I'm going to try today, hope it works! And thanks for the great write up, I never would of though of covering the magnet with plastic.

david.carlini.1 (author)2014-09-14

Hi, I started this method with a VHS. Then while the tape was in the acetone, I read the comments and saw that it doesn't work with VHS.

So I thrown the video tape in my BBQ and put it on fire because I was very angry.

I've lost a part of my arm hair...

Then I took the ashes and realised it could still work with it.

And it worked :D

thecrazylol (author)2014-04-12

how much ferrofluid can you make with one video tape?

nerd7473 (author)2013-03-30


Newty (author)2008-12-07

This does look easy. But I'm not sure I'd call $200 per cup a "very low price" when a $60 per cup result tops a Google search for "buy ferrofluid". Does this instructable produce better quality stuff? To whatnot: The dish soap is the surfactant and also emulsifies the oil and water. Apparently you can make magnetite more soluble in oil or kerosene using oleic acid, or more soluble in water with citric acid. I'm also reading a journal abstract here where they got crazy and dissolved in water particles made of magnetite+styrofoam, coated with oleic acid, surrounded by oil, coated with dodecyl sulfate.

hcaz-301 (author)Newty2012-05-24

You can buy it for about £10 per 30ml on ebay

aristide202 (author)Newty2012-04-04

Good comment , compliments.

beehard44 (author)Newty2010-03-19

yes, it is cheap, but you forgot onne thing, Delivery price. Maybe it is no big deal if you live in the US, but change the setting to the philippines, it's a different story...

Zujus (author)Newty2008-12-08

he he ;D This is one of my first instructables, actually it is way better to buy thing if your point is quality. ;) I made better one "Real" ferrofluid so this is very simple and basic version. But still pretty cool ;)

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