Flexible Stone Pots

Looking for a way to decorate your garden or house? These pots have a stone look, are flexible and light and the best thing: they are easy and fun to make!

The pots are made from a material I call "sandy foam". A combination of expanding foam and sand. More explanation about the material I used for this pots, experiments with it and all the possibilities, look at my previous Instructable: Flexible And Light Stone Material.

To create the pots, we're going to "flatten" the sandy foam between two cups. You need two cups that fit into each other and give the foam enough space to expand and shape around the smaller cup.
Grease both cups in with mold release. I used grease from a "Body Double" package of Smoot-on. Grease the inner side of the bigger cup and the outer side of the smaller cup.

For the sandy foam material I used flexible polyurethane foam of Douglas & Sturgess. To create the foam for the first layer I used 0.10 oz of part A, 0.30 oz of Part B and 1.30 oz of sand. Mix it for at least 30 seconds, and add little amounts of sands in between. I mixed it in a smaller cup to make it easier to pour the foam into the greased bigger cup. The foam is pretty thick and sticky after mixing, so I needed a little help of two spoons to get all the material into the bigger cup.

Once you poured all the sandy foam into the bigger cup, press the smaller cup into the bigger cup to flatten the foam between the two cups. You can see the foam shaping itself around the smaller cup. Using a transparent cup makes it easier to keep track of where the foam is going.
As the foam is expanding, it will press the smaller cup upwards. To make sure the smaller cup will stay in the foam, you can put something heavy in or on the cup.
Wait until the foam is dry and take the smaller cup out of it. This shouldn't be too hard if you greased the cup.

In case you want to make a second layer, let the dried sandy foam stay inside the bigger cup. Building a second layer can be interesting if you use lighter or darker sandy foam. You can achieve this by mixing more or less sand with the foam. For a lighter second layer I mixed 0.30 oz into the same amount of part A and B as I used for the first layer.
Smear the lighter sandy foam above the first layer around the edges using a spoon or mixing stick. Now press again the smaller cup into the bigger cup, wait until the second layer is dry and pull the smaller cup out of the foam.
The most easy way to remove the dried sandy foam from the bigger cup is to cut the bigger cup and tear it until the bottom, so the cup opens up and you can easily remove the dried sandy foam from the cup.

A stone looking cup appears when you remove it from the bigger cup.

Experiment with different molds and shapes and amounts of sand. I discovered that when you do not grease the bigger paper cup (the white cup I'm using in the previous steps), the sandy foam will attach to the paper. Removing the paper from the dried foam is difficult, but it creates a very interesting and rough structure, see the last picture.