Delft casting technique - Philip and Else Quanjer

Philip Quanjer, Else Quanjer

Delft casting® technique

The silver did not sufficiently fill the mould at the top of this relatively large object.

The silver was not sufficiently hot when casting. This is probably by far the most common cause of failures with the Delft casting technique. It is the most likely cause if you notice that the silver hardly filled the vents. If the silver is not sufficiently hot all other factors that may lead to imperfect castings (pouring the silver too slowly, vents too narrow or too few in number, mould not placed level, narrow pouring gate, too large and thin object) come strongly into play.
Vents too narrow or partially obstructed, or too few in number. Air cannot escape sufficiently rapidly, hence silver flows too slowly and solidifies prematurely.
Vents not in the right position. Put them at the edge of the mould so that they only fill up with silver after air has had an opportunity to escape from the mould.