This morning we made an "emergency" trip to the Staples down the road to stock up on Elmer's White Glue. Earlier this week we found a video recipe on-line (there's many) and cleaned out our glue supply making that first batch. This activity proved to be so much fun, keeping the kids amused and doing something "sciency" for hours, that we thought we'd try it again today. Laurent summed it up nicely with "these are incredibly fun".
We learned to cover the putty when you're not using it. We left it on the table overnight uncovered and it stiffened up and didn't do all the same cool stretchy things it did the first day.
We also learned that you can mask the smell of rotten egg glue (don't ask me why our glue smelled like rotten eggs) with essential oil. So our first batches were blue geranium and green peppermint. Today's batches are simply colored, not scented.
Speaking of colorants and fragrance you may be wondering how "natural" this activity is. I confess that the colors we used are grocery store bought, the type found in the baking aisle. While I don't want my kids ingesting artificial colors I don't mind them kids playing with it. If you're hard care about this kind of thing you can buy natural colorants or maybe use beet juice instead of water.
As far as the other ingredients, borax is totally natural and it turns out the glue isn't so bad either. I have no idea how glue is made, well some idea but I don't want to know the details, but Elmer's White Glue can be composted which means when you're done with your putty you can safely toss it in the compost heap.
Today's goop, tomorrow's soil, that's my kind of craft. Perfect rainy day activity. Provides a good (& safe) chemistry lesson and provides hours of amusement.