Building a Bronze


The Gloucester Fishermen’s Wives Memorial

 A brief overview of the many stages in building a monumental bronze sculpture.


Drawing  

Drawings on paper are made as the concept for the composition is roughly approximated.
A drawing can quickly demonstrate an idea for the patron as well as the sculptor. 


Maquette, Clay 20 Inches High

Maquette  

One or more small clay studies, no more than 20 inches high, are made to create the three dimensional composition.
The basic composition and the gestures of the figures are determined in this small scale where change is relatively easy. When the concept has been approved the clay maquette is cast in plaster using the waste mold process.



Bolder Installation

Boulder Base  

After a careful search, a suitable boulder, weighing about 20 tons, is procured for the base for the bronze figures. A structural engineer designs the massive 20-ton foundation under the bolder, to withstand frost, wind, and water damage.  The boulder must be installed at the site before the scale model can be accurately built.



plaza

Site Design  

Working closely with the sculptor, a landscape designer creates a site plan which is crucial to the sculpture’s appearance
in the context of the landscape and to the experience of the visitor to the sculpture site. 
Issues such as flow of foot traffic, seating, lighting, plantings, close and long views of the
and access are all addressed in the site plan.
The public was invited to help fund the building of the sculpture by purchasing engraved granite paving stones for the site.



DCP Survey GFWM

Shooting the Locations of the Feet on the Granite Base

A surveyor’s transit is used to make careful measurements of the top of the boulder base.
These specific spatial locations are duplicated in half scale model so that feet of the figures
will eventually stand correctly on the uneven surface of the bolder base.




 Half Size Clay

4 Foot Clay Scale Model


GFWM half plaster, Lafferty copy

4 Foot Plaster Cast of Scale Model

The scale model is one half the size that the final bronze will be, in this case it is 4 feet high.
In this model the gestures, proportions, and anatomy of the figures are carefully worked out
before the details of clothing are modeled.
The scale model is shown above in clay and after it was cast into plaster using waste molds.
Once it has been approved, the scale model is waste-mold cast into plaster.
Work directly on the plaster refines the details.




Full Size Wood and Steel Armature



GFWM 10-2-00 no. 04 copy

Full Size Clay  

The full size clay, 8 feet high, is a straight forward enlargement of the scale model.
A plaster cast of the top of the granite boulder base is made using a piece mold.
On this exact replica of the top of the base a strong armature is built from steel and wood.
Selected locations called points are transferred from the scale model to the full size armature
using a pantograph (a pointing machine.)  The actual points are matchsticks set precisely in plaster.
They constitute a three dimensional guide for the sculptor in building the clay.
Adjustments and improvements are made to the forms as the piece grows to its full proportions.



Rubber Mold  

When the clay has been completed, flexible rubber molds are made in sections on the clay
and these in turn are backed up with steel reinforced plaster “mother” molds.





Wax  

At the bronze foundry, wax positives are made in the rubber molds.
The wax is in pieces that are the exact thickness that the hollow bronze will be.
The sculptor works on the waxes to improve and correct details.




Ceramic Shell  

Gating channels, "vents and sprues", made of wax, are added to the wax to provide routes for the
melting wax to escape and for the bronze to flow in to the mold.
The wax is dipped into a ceramic material and a shell is built up by dipping and drying many layers.
Then the shell is baked hard and the wax is melted out.




Bronze  

Molten bronze, at about 2000°F , is poured into the molds where it fills the void left  where the wax once was.
This is called
 Lost Wax casting . After cooling, the ceramic shell molds are broken away and the bronze is exposed,
faithful in detail to the original wax.  The gating channels, now solid bronze, are cut away.
The sections of the sculpture are welded together using the same bronze alloy as the poured casting.
Upon a plaster cast of the top of the bolder base, the feet are fit to their particular locations.
A system for attaching the bronze to the boulder is specified by a structural engineer.

Patina  

When the bronze is fully assembled and all the details have been finished by grinding and chasing the metal,

it is sandblasted to remove any traces of oil on the surface.  With a propane blowtorch, the metal is heated
and various chemicals are applied to achieve the desired color or patina in the metal.
A thin coat of wax is applied to bring the patina to life and to protect it.





Installation

The 1200 pound bronze is trucked to the site where the boulder base has been drilled to accept the stainless steel rods which are welded to the feet of the figures. After the fit of the feet and the stance of the figures have been checked on the stone, a super-epoxy compound is placed in the holes, and the bronze is thereby permanently attached to the base.






485_P1010048.JPG

Maintenance  

The sculpture should be washed and waxed once or twice a year to maintain the original patina.



Copyright 2017 Morgan Faulds Pike        The contents of site may not be used in any way without express permission from the artist.