Over the last year I have noticed an interest in finding
oil-tempered casting sand similar to the patented Delft clay.�As a
person who must soon teach a low-tech jewellery casting workshop,
this is of particular interest to me, though I love the Delft clay
and am suffering from some equal-competition style qualms regarding
this...nevertheless, here is a site describing a home brew casting
sand that seems to come close to Delft in quality.�This is similar
to petrobond sand, which on my screen looks an AWFUL lot like Delft.
Good luck, and let me know if any of you have tried this.