We have always hesitated before recommending the use of Styrofoam/Polystyrene as a sculpting core.
In the Arch project, Steven and Kim were working with straight foam as an experiment to see how it performed with Pal Tiya Premium (PTP).
Surprisingly it worked, with two significant catches.
Starting out, their concerns were straight foam is crumbly so PTP has never stuck to it. Also, that the foam would also draw the moisture out as our product cures.
They discovered that spray foam (from a can) does draw the water out, but white polystyrene foam doesn't.
By propane torching and burning back the surface of the Polystyrene, the surface shrank, fused together and became quite spiky, a perfect sticking surface for vertical climbs.
Polystyrene is still extremely messy. While cutting and trimming, the white beads got everywhere. They took a lot of trouble to make sure the beads didn't get anywhere birds could eat them.
The fumes from the burning are horribly nasty and must be done outdoors.
The spray foam is expensive and the fumes can be toxic. Use only in a well ventilated space.
Building the arch from Polystyrene only took about three hours. We suspect it would take about 4 hours to do the same with cardboard and foil.
In conclusion: Foam will work, and there will be professional applications for this technique. However, if you have a simple budget, a small studio and limited ventilation, Foil/Cardboard is still a great option.
Don't forget to look for the Assyrian Warhorse sculpture in the video and watch till the end for outtakes!
Drop a comment over on YouTube and let us know what you think.
This also helps YouTube serve our videos up to more people ☺
The Pal Tiya Crew
Creators of Pal Tiya Premium: Add water. Knead like dough. Sculpt. Place in your garden. Cures permanently stone hard. No firing. No Molds. No Kidding.