How bronze plaques & memorials are made

 

 

 

 

 

 

Most bronze plaques and memorials are cast in sand molds.  When you watch foundry
workers creating them, it looks easy, but only because they have spent many years
perfecting their trade.  Here is a very brief description of how it is done:

The process starts out with a pattern (often made of wood) that looks exactly like the
finished piece.  The pattern is encased in sand, between two frames --called a “flask” --
designed to be separated and reassembled in the same precise position. 

After the sand is compacted, the frames are separated and the pattern removed.  The
sand stays in place and retains the image of the pattern in every detail, only in reverse,
as a hollow space.  After cutting holes for the molten metal to flow into the hollow
space (the gate) and for the air to escape (the vent), the flask is reassembled.

Bronze is melted in a crucible, a pot-shaped container that is able to withstand the
high temperatures of a furnace, around 2000°f.  When the right temperature is
achieved, the crucible is lifted from the furnace and placed in a device that allows it to
be maneuvered into position to pour the molten bronze into the mold through the gate. 

After the mold is completely filled, it is allowed to cool. The rough casting is then
removed, the gate and vent (which have become solid metal) are cut off, the raised
portions of the plaque are carefully ground (leaving a brighter surface that makes the
plaque or memorial readable) and the background darkened.  The final step is to apply
a clear protective coating to preserve the metal.

Click the link below to view a bronze plaque being created, courtesy of Nisse foundry &
design, custom bronze casting: http://www.sasktelwebsite.net/jimdeb/casting.htm