Australia's Science Forum

A teacher has just asked me for liquid starch to make silly putty tomorrow as a "fun" last day of term prac. Any ideas? I think it may be what people use to starch clothes but not sure if it is available here.

Pretty sure you can use any form of starch including cornflour. Its the ratio of starch to water that makes the slime. I have a recipe somewhere i will look for it.
Lorrae

Her recipe says

Silly Putty:
2 parts craft liquid glue
1 part liquid starch

The recipe i have says:
Pour a cup of cornflour into a mixing bowl.
Stir in a small amount of water(start with a tablespoonof water)
If mix is too dry add water by the teaspoon until the cornflour in completely wet but there isn't any water on the surface. Add a few drops of food colouring and stir slowly into the slime.

and that is it.
Now I have never done this we have only ever made slime with PVA so I don't know if you can play with it like the other slime.

Lorrae

ive made it with corn flour, when you agitate it, it is thick, when you stop it goes runny again.

Its pretty fun! (well, for me)

We use borax and PVA (craft) glue. You should be able to get borax in the cleaning/laundry section of a supermarket. 25ml glue (I use a measuring cylinder and water, pour it into a plastic cup and draw a line in permanent marker on the outside so they can just add the glue to the line - cleaning glued up measuring cylinders is NOT FUN!) and 10ml borax solution. I just stir a few heaped spatulas into about 250ml water. Not too accurate. They add food coloring to the glue and stir (paddle pop sticks) before adding the borax or it doesn't mix properly. Add borax slowly while stirring! 2 person job and a ball should develop. There will be liquid left as well. Wash it under a gentle tap and dry with paper towel (if it isn't solid enough, add some more borax).

Otherwise I have used the cornflour method as well, but I haven't done cornflour and craft glue together!

The last time I went looking for starch in the laundry section of the supermarket the only starch I found was in spray tins. So whatever prac it was needed for just didn't happen.
Lyn.

Is it a prac she has done before or just found it in a book. ( We all know how unworkable some of them are)

For reasons unknown, probably left over fromYr 10 Projects many years ago, I have 2 different bottles of Liquid Starch in my chem store.

I tried the prac using these 2 mixed 1part starch to 2 parts glue, and then with the same ratios the food testing starch mixture I had in the fridge.

All just end up with a more liquid version of the glue as if you added water, nothing puttyish at all. just a liquid that would then dry like glue on the benches etc.

I added some cornflour to the glue and ended up with somerthing that is just a bit more sticky that starch and water, but not different enough to waste glue and cornflour and then face the clean up of the benches etc after.

Thanks for that. I thought about testing it myself but haven't had a chance yet. I think she just found it somewhere, sounds American to me. I considered suggesting the borax version but she also wants to do making sherbet (which always worries me anyway) and thought of sherbet and borax in the same lesson sounds like a recipe for disaster! I'll just say no to the silly putty. Maybe suggest breadclip speedboats in milk instead.
Thanks everyone.

Borax is only sold at franklins and some IGA stores. Woolworths doesn't sell it anymore.

If you did decide to go with cornflour make sure it is CORN cornflour.
It doesnt work with the wheaten cornflour that is now sold.
Coles brand is corn cornflour.

borax is sold at Bunnings

is it Sunray18? I called our local Bunnings and Masters and they told me they dont carry that item. I have been on the mckenzie website - (borax makers) and they have a list there of people that sell borax and bunnings isnt on there. I only found this out during science week when we did slime and I couldnt get borax at woolies.

Superbug!

Buy sodium borate from a chem supplier!!

I have been buying Borax from Coles. It is located in the cleaning aisle. It is Bare Essentials brand. If I see it available on the shelf and know that teachers are intending to make slime I buy a number of containers of the chemical. Just make sure that you read the label because they also sell another chemical (think it was bicarb soda) in the same coloured container. Was in a hurry one morning and just grabbed whatever they had and took off. Had to take back two of the containers because I had grabbed the wrong stuff.
Lyn.