Today my son did science with clay, he took 3 recipes for clay made each one and then made a chart on differences and similarities of each, which he liked best ect...
recipe #1 cornstarch and water, you just take a bowl of water and mix in water it should
be sort of like glue and will harden when you play with it and when you stop it
will run off your hands, it is very much like quick sand. this washes away easily
recipe #2 2 cp baking soda, 1cp cornstarch, 1 1/2 cps water, mix soda and starch in
saucepan mix in water boil over medium heat until boiling, stir out any lumps and
cook until it is the consistency of mashed potatoes. it goes from being very loose
to very thick in about 2 seconds. put it on a plate covered with a damp rag
to cool, we added a few drops of food coloring to it before it cooled and
then kneaded it to mix the color in. watch out it is very warm to start out
with, parents should check the temp before letting little hands knead the clay.
recipe #3 2/3 cp salt, 1/3 cp baking soda, 1/2 cp constarch, 1/3 cp water, 1/4 cp water
in saucepan mix, salt, soda, and 1/3 cp water bring to a boil, in bowl mix
starch and and 1/4 cp water. when 1st mix boils pour into the bwol with 2nd mix
stir until smooth let dry about 2 hours before using.
We liked recipe #2 the best it was very smooth and holds it's shape nicely. My son decided to call it "mashed potato clay", it really does look like mashed potatoes when it first gets done cooking. Both recipe #2 and #3 can air harden. And you can paint them when they are done, or add food color before they cool. If you do not want them to dry out just put them in a ziploc baggie and throw them in the fridge.