It's a pretty simple concept. Select your favorite washable poster paints and thin them with a bit of water. Use a spoon, eyedropper (excellent for fine motor skills) or paintbrush to add drops, blobs and splatters of paint on a paper plate. Then put the plate into a salad spinner and spin it.
Viola! You have a beautiful piece of artwork. The key to success is to avoid putting too much paint on at once. That can be a real mess, and the colors just muddle together into a yucky brown. Some kids like to put colors on randomly. Other like to make patterns, which can yield great results. One girl painted her whole plate one color, then added drops over it, which looked a bit like tie dye when it was done. Another boy added color in layers, one at a time, which made some really lovely, subtle blends.
If you're feeling really adventurous, lay down a thicker layer of paint and let it tack up a bit. Put the plate in the spinner and place a handful of marbles in there as well. Give it a spin, starting and stopping randomly, even shaking the spinner gently, and you'll get what I like to call "slug tracts." You can also put globs of thinned white glue, sprinkle on colored sand or glitter and spin it. (Use more than I did for the example below.) It's all kinds of awesome.
- Does the thickness (viscosity) of the paint affect the artwork? the distance the paint moves across the plate? (For older kids, actually plan ratios of paint to water and test each on the same plate.)
- Does the type of paint used affect the artwork? in what ways? (Compare poster paint, watercolors, acrylic, food dye...)
- Does the speed of the spinning matter? Does it affect coverage of the plate? the shape of the artwork? the distance the paint travels on the plate? (Use a stopwatch to determine spins per minute. Older kids can test the effects of positive and negative acceleration, too.)
- Does the amount of paint used affect the area of the plate covered after the spin? the shape of the final outcome? (Carefully measure teaspoons, tablespoons, etc.)
- Does the type of plate used affect the artwork? (Compare uncoated paper plates to coated ones or styrofoam.)
And once you're done with that, give a go at exploring centrifugal motion! Your salad spinner can make a great centrifuge in a pinch. I just cut up egg cartons, glue or tape them together and add test tubes of various liquids. You can use small jars or the plastic tubs that sometimes come with bouquets of cut flowers, so long as you cap them well with aluminum foil and tape. Then fill each tube with an equal amount of liquid. (OJ with lots of pulp and vinaigrette salad dressings work particularly well.) For the best results, be sure to balance your centrifuge and SPIN! You're going to need to keep it spinning for a few minutes, so taking turns makes sense, but you will be able to get separation.
Anyway, it's tons of fun. I hope you'll get out your salad spinner today and have some fun. Be sure to post your artwork or the results of your experiments!