To make a small plant pot for cactus I first made an outer mould using 2mm thick rigid foamPVC sheeting cut into squares of 100mm. I stick them together to make an open ended box using duck-tape. The open five sided box was then stick to a larger sheet of hardboard to stop it moving about when I am filling it with coloured cement.
For the inside mould I used an empty large plastic yogurt pot which happened to be the perfect size to fit inside the five sided open box that I had made with 2mm thick plastic.
I mixed a small amount of white cement with a small amount of fine kiln dried paving sand and poured it into the box mould to about an inch in depth, I let this dry for 24 hours.
I then made another small mix of white cement mixed with coloured blue printer ink and then poured that into the mould, this time I also put the inside mould in position, 24 hours later I made my final mix of white cement, fine sand and colouring and filled the mould to the top of the box with the inside yogurt mould in position which will make the inside of the plant pot.
24 hours later i removed the iner mould and the outer mould, filled it with sandy earth and put in some small baby cactus.
The plant pot was then placed in our bathroom at home for all to enjoy.