I thought it may interest hypertufa fanatics to see the results if a recent project i have been working on.
The hypertufa head planter pictured was constructed from a cheap polystyrene head mannequin which i adapted to include a square base by sticking on a further polystyrene square.
The crown of the mannequins head was removed and a recess cut out to accommodate plants when the planter has finally cured.
The finished polystyrene sculpture was then fixed to a plastic pastry sheet with plasticine smoothed round the base edge
The whole poly sculpture was then coated with 9 thin coats of brush on latex rubber. I had been advised not to use many coats because it makes the latex mould difficult to remove from the original. The resulting 9 coat mould worked fine but in future i will go a little thicker with say 12 coats just to give a firmer latex mould. The latex coats were also extended about an inch beyond the edges of fhe base. This provides a good flange to adjust the mould when in use.
I allowed an hour between latex coats and this worked for me.
After there final latex coat i allowed the latex to dry over night until all the latex became tanin coloured with no white patches of uncured latex.
I then divided the sculpture in half with a ridge of plasticine and also on the working side a border of aluminium foil. The first half of the sculpture up to the upper rim but not inside the recess was then coated with a jacket of plaster of paris bandages. I made the jacket 5 layers deep. The plasticine ridge was then removed leaving the aluminium foil in place as the divider between the two halves of the jacket. I brushed the exposed side of the foil with dish washing liquid to prevent the second side of the jacket sticking to the first.
The second half of the jacket was then finished as the first had been.
The jacket and latex and original were all left to set for 48 hours.
I removed both halves of the jacket. Removed the latex from the poly original. I then rinsed out the latex mould and inserted an empty plastic plant pot inside the recess at the top of the latex mould. The rest of the latex mould was then put inside the two halves of the jacket. The jacket was secured with packaging tape in 3 places.
Loose hypertufa mix in 1.1.1 proportions was put into the mould from the base and i repeatedly shook the mould as i filled it to lose air bubbles. When the mould was full i inserted a chopstick all the way through the hypertufa mix until it made contact with the base of the flower pot which was inserted in the recess at the top of the head. The chopstick when removed will allow water to drain from the planter.
After 24 hours the jacket and latex mould were removed and the finished planter was brushed with a wire brush to give the desired textured finish.
