Indiana Jones Holy Grail
I made this prop as a christmas present for some friends in 2008. They had gotten a replica of the golden idol and the staff topper earlier in the year and I thought this was something they'd like to add to their collection. If I were to do this again I'd skip the internal plastic parts as they wound up being more of a pain than a help.
I started with a 4" diameter hemisphere from the craft store, a length of 1" PVC pipe and some styrene.
I then got some air-drying terracotta clay and covered the form. I wanted to use terracotta as it's what the original prop was made from and I didn't want to paint it. I had to stop halfway through adding the clay but some plastic wrap kept it moist until I could return to it.
After the clay was added everything looked pretty good and it seemed the project would go smoothly. Unfortunately as the clay dried it shrank and cracked around the plastic core. It took about a week of adding clay, letting it dry, sanding then filling in the cracks with more clay to finally get it to stay together. Eventually on the inside I cheated and used some non-shrinking epoxy putty since it'd be covered by the gold leaf.
Once I had the cup complete I sealed it with a coat of clear spraypaint. Without the clear coat the glue for the leafing wouldn't stick.
I'd never leafed anything before so I just picked the easiest looking kit at the craft store. It seemed to work fine with a little trial and error.
Once the leafing was done I finished the cup with some light mistings of grey and some heavier spraying of white. While not the most accurate replica it came out well enough and my friends liked it.