For J's 2nd birthday, we did a very non-toxic cornstarch based goo, and it was a hit, but it was VERY messy. I told the director that I'd try some homemade silly putty recipe this weekend and report back.
So here's the recipe for homemade silly putty that I went with. I actually found one with measurements, so I went with that: 2 cups Elmer's White Glue, 1 cup StaFlo (according to all sources it has to be the exact brands) + food coloring.
Combine ingredients into a plastic zip baggie. If you use 2 cups of glue + 1 cup StaFlo, use a quart size bag, as the sandwich bag was too small. I recommend 1 4oz bottle of glue + 1/4 cup StaFlo for something a little smaller (or even half that!).
|We're not that patient|
Kneed, press, shake the bag. After a while, solids form. This is where you should start to get your hands dirty. We kneaded the mixture inside of the bag some more before pulling it out. We started stretching, folding, and kneading some more for about 15-30 minutes.
|Mixing it together|
|Is this what pulling taffy is like?|
|This has to be my fave pic of the day|
This made a giant amount of "silly putty"**.
I left it out all day to dry (on top of gallon plastic baggies since the putty picks up every piece of dirt/crumb), kneading it intermittently between my other Saturday duties/obligations. While we were meeting our new neighbors, I was kneading the mixture. The new neighbor's 3 and 5 yr old girls thought the putty was great! While I continued kneading, J and our two new friends divided half of my putty and started playing. They all seemed intrigued by the stringiness of the putty (all over the freshly cleaned carpets, I'm sorry :-( ).
|What's left after we shared with the neighbors - still drying|
**I'm disappointed that this is called "silly putty" hence the " " 's. It's a very similar texture to Nickelodeon Gak back in the day (yes, I dated myself) - it even makes the farting noise. I didn't point this out to my 3 year old boy yet. It's still great and has a lot of similar properties to silly putty (viscoelasticity). See below lesson for how to demonstrate this property to kids (if they don't figure it out on their own). After drying overnight (and getting a dry film on top that we removed since we didn't wake up every hour or two to knead it like we were doing during the day), it felt more like real silly putty, and it bounced a little, but not super high bounces.
Safety warning: though Elmer's is non-toxic, liquid starch, such as StaFlo, probably shouldn't be consumed. I don't see warning labels, but it has lots of chemicals. It's used to starch clothing, not for eating.
We also did a simple homemade playdough recipe when the blog was a baby. It was cooked, which makes it hard for kids to do themselves. I found another no-cook playdough recipe on Cooks.com to try today. I substituted cream of tartar for alum (there was a comment that said in England they use c of tartar as a preservative, similar to alum - and I've seen it on other playdough recipes, so I did it too instead of buying alum). It's super salty (I didn't even use the full amount of salt) and gritty, but it'll work for this lesson.
|No cook playdough|
Lessons to learn for this messy, silly lab:
Mixing different ingredients
Different chemical properties (viscoelastic, plastic)
Making a mess
How do different materials react to different stresses?
Things to do to demonstrate:
*Slowing stretch or let the putty hang. What happens?
*What happens when you pull the putty apart quickly?
*Squish the putty into something (like a cup). Does it make any sounds?
*Which material keeps its shape when you squish it?
*What happens if you let the putty sit for a few minutes?
*Can the putty bounce? Can the playdough bounce?
J's quote: "It's like icky sticky bubble gum!" when referring to his first experience with the silly putty.