Easy $3 Ferrofluid and Other Explorations With Magnetic Slime

Our DIY class has been struggling with oogoo, but a comment on the oogoo instructable

https://www.instructables.com/id/How-To-Make-Your-O...

inspired us to try adding iron oxide and from there, a stray comment about adding iron oxide to silly putty left me thinking about magnetism in plastics and non-Newtonian solids.

Step 1: Base Recipes

We used the
oobleck recipe from http://www.kinderteacher.com/oobleck.htm and flubber recipe from http://www.kidactivities.net/category/Art-Goop-Sl...

and iron oxide at $4/lb from amazon

http://www.amazon.com/s/ref=nb_sb_noss_2?url=searc...

and opted not to have the kids scrape it off old cassette tapes soaked in acetone, but that was just a personal preference.

and added a good amount (approx 1/4 cup) of iron oxide to each mixture.

Note: Because the iron oxide is a fine particulate, masks are needed

Step 2: Results

The oobleck reacted just like a ferrofluid! It was really exciting and the older kids were amazed and impressed.

Step 3: Flubber Results

The flubber didn't do so well, but the kids had a lot of fun with it.
It was only mildly magnetic, and next time, we'll add the iron oxide before we mix the borax solution with the glue solution. By the time we started mixing it in, it did not want to mix with the flubber, and although eventually it did get mixed through the gel, I think we did not mix in enough iron oxide to affect the properties of the material. Highlights included finding out that it would reflect the shock of being punched back to the puncher when wrapped around the arm (is this a possible new motorcycle helmet insulation - maybe another DIY project to find out)

I'd love to get suggestions for working with oogoo and getting magnetic substances off of rare earth magnets