Methods

My sculpture mostly derives from the marine environment, landscape, the figure, and the physical forces of nature. Repeated linear bronze elements, cast in foundry sand, are pieced together suggesting three dimensional drawings of volumetric objects intended to create a tension between abstraction and representation.

1. We begin the casting process by filling a frame with foundry sand, a mixture of synthetic binder, sand, and oil, making a plastic mixture that, when compressed or tamped, will hold the impression of a form pressed into it.

2. After the sand is tamped, we screed it off leaving a level, flat surface on which to press objects, such as tree branches, rocks, tools, wire, sculptures, or anything in the studio that catches the eye. This can be a very creative time, if I am not making repeated shapes, providing the opportunity just to draw in the sand.

3. This is the finished mold, in this case duplicate shapes of a tree branch, cast in multiples of three, that were used to make "Uwatenage". The bronze is poured into the "cup" at the bottom of the mold, and the bronze flows gently into the void created by the branches.

The shapes, cast as they are on the flat, two dimensional surface, are cut from their "cups", and the connections ground and polished. They are then usually bent into three dimensions, either to conform to a rudimentary steel armature, or just to "encourage" three dimensionality in the more improvisational sculptures. There is still room for improvisation on the surfaces of the sculptures made over armatures.

Click here to view a movie of the pouring process (1 Mb)

4. The silicone bronze, in a #60 silicone carbide crucible, is heated for about 45 minutes in an oil fired furnace to about 2400 degrees Fahrenheit - slightly higher than if it were being poured into an enclosed mold, and poured with dispatch into the pouring cups at the base of the molds.

Depending on the mass of the mold, the castings can be lifted from the sand in about 30 minutes. It is usually about time for lunch by this time, so we pull the castings afterwards, and start again.

The sand is recycled with some binder and oil added, remixed (mulled) and it is then ready for the next molding procedure.

Copyright © 2008 John von Bergen<