This instructable explains how to make your own ferrofluid without using any chemicals.
The magnetic particles will be extracted from an audio cassette and they'll get mixed with vegetable oil (regular cooking oil).
This instructable is relatively short because there isn't much more to explain about it. It's really easy to do, but it takes a few hours to do.
Please pay attention to all notes regarding safety!
Step 1: Requirements
- an audio cassette.
- a sharp knife.
- vegetable cooking oil.
- a small bucket for the ferrofluid.
- a metal plate (see step 3).
- a strong magnet (not required for actually Making the ferrofluid).
- some stick to mix the particles with the oil.
- a lighter or matches.
- a fire extinguisher for if you set your house on fire with the lighter.
- a piece of cardboard with small ridges. (or no ridges at all is even better)
Step 2: Extracting the magnetic band from the cassette
In this step we'll separate the magnetic band from the plastic band.
- Take your knife, scissors and the tape, and place the knife in the same position as in picture 5 (the cassette also at the side of your table).
- Put the scissors inside the left hole of the cassette. They are used to rotate the tape. (see picture 6)
- Start rotating your scissors and the magnetic band will get separated from the plastic band.
- If this does not work, try with another cassette. Not all of them seem to work. It should come off really easily!
What we're actually doing:
We are bending the tape around a sharp edge. The plastic just bends around with no problems, but the magnetic tape comes loose because it can't take such a sharp bend. If the magnetic band is sticking too hard on the plastic band it'll also just bend along the sharp edge. Use another cassette if this happens.