I cast about 6 or so solid skulls, painted them, removed a few teeth at ramdom,
placed them and then went for the hollow ones.
A couple of elastic bands held the split together then it was an operation to pour enough
fastcast resin to fill about a quarter of the mould the i just stood there with my thumb over
the pouring hole and just waved my hand around to spread the resin about the whole thing.
As it turned out, a crude but effective technique.