Making castings



I have made resin castings of some of my stone sculptures (originals above, casts below). Choosing simple, flattish shapes means I can make my own molds: making them for complex forms is a speciallist job. 


I thought this would be  quick and easy way, but in practice each copy is almost as time-consuming as the original carving

First step : making a mold


I make a waterproof barrier around the carving and coat it with a  rubber compound. The mold is still in place on the sculpture (left) and removed on the right. 

Next step: casting

With the mold back in its wooden surround and on acast plaster base, I paint a 50:50 mix of polyester resin and a metal powder, such as bronze, inside the mold, to a depth of a few mm. (left). Once set, I add a thicker layer of resin mixed with a  filler such as  slate powder (right). This forms a very durable shell which I fill with plaster and let it set. 


Last step: polishing and patination

I seal the bottom of the sculpture with a final layer of resin and then remove it carefully from the mold. At this stage, it is a dull uniform colour (left), but abrasives bring up the highlights, and  various chemicals are applied to add colour, such as darkening or verdigris.