Our kids and I did this project back on Father's Day. It was a fun way to spend an hour or so. Hypertufa is a simple mixture of ingredients that creates a clay-like substance that you can then mold into various objects and when it cures it hardens like concrete but is much lighter weight.
This was my second hypertufa project, the first one being a VERY crude ode to the guardians on Easter Island - although it ended up looking more like my dearly-departed granny when it was all said and done.
So here's how to make the hypertufa 'clay'
Portland Cement
Pearlite or Vermiculite
Peat Moss
Large container for mixing
Something to use as a mold. [For this project I used a large wooden bowl and a plastic food container.
Pam or non-stick spray
Plastic
Equal parts Portland Cement, Pearlite and Peat.
Mix the dry ingredients in a large plastic bin or wheel barrow.
ONce mixed slowly add water and mix well. Keep adding water and mixing until the mizture is clay-like...when squeezed with your hands a small amount of water should squeeze out of the mixture.
Once you have the mixture to the right consistency [don't add too much water!] you can get your mold ready.
Line the mold with plastic. Spray plastic with non-stick spray. Begin to pack on clumps of the 'clay' onto your mold...packing it tight. Your mixture should not crumble - if it does there isn't enough water.
For this project we packed a plastic food storage container with the 'clay' to use as the base then joined the two together.
Be sure the walls of the birdbath are thick enough...it needs to be thick to have structural integrity...and once dry it will be lighter in weight than it looks.
Leave your creation to cure in a cool dry place for 2-3 weeks. I've read that you're supposed to spray it with water occasionally, but I didn't bother doing this and it turned out fine. :-)
The result here is a nice-looking asymmetrical bird bath and it's something the kids and I made together, so it's even better!
