The Construction of Neptune, Shell and Fishes
by Thomas M. Latané
The arch elements were designed so that the asymmetrical figure of Neptune, framed by the symmetrically balanced fish and wave scrolls, would be protected from behind (where he is hollow) by the large shell. The wide use of dolphins in Renaissance art of aquatic theme is mimicked, but our use of lake sturgeon is more regionally appropriate.
Before lifting a hammer, I prepared a full size drawing of Neptune, shell and sturgeon as I envisioned making them.
I began the project by making a halfsize test shell of steel thinner than the final shell and a test section of the lower arm in full size. Neither of these was taken to completion. Both tests gave me a feel for what could be done hot and what cold, and for how much larger the pattern should be cut than the original full-size drawing. The flutes in the surface of the shell would cause a drawing in of material from the sides, while giving Neptune extra material around the edges would allow depth to be created without stretching the metal as thin in the center.
Pure iron was chosen for most of my work because this material, which has recently become available to smiths in the USA, has superior malleability which allows work to be done cold in a heavier thickness.
The shell blank was cut from 1/8” thick iron plate with a Beverly shear and chisels and the position of the flutes was transferred to the iron from the paper pattern with a fine point punch.
The blank, larger and heavier than a trash can lid, was heated in a bonfire and dished over a depression in a stump. An apprentice and I handled the hot iron with tongs, dancing around the stump as we worked to avoid the smoke rising from the wood.
The simple dome was refined cold and the flutes creased over a specially-made valley tool held in the vise. The hammer used was a straight pein also made specifically for that process. While the greatest number of tools may have been made to chase the details on Neptune, the heaviest tools were forged to shape the shell. Many of these were also useful throughout the rest of the project.
Planishing the flutes and lobes of the shell took much more time than anticipated and work had to be reversed frequently front to back to leave a satisfactory finish on this piece which would show from both sides.
Neptune was tackled next. Again the form was dished hot over depressions in wood and pounded over steel stakes. When what appeared to be total depth was achieved, the hollow backside was filled with melted pitch. Then the pitch-stiffened Neptune was anchored with more hot pitch to a stump or other solid work surface. When the pitch cooled, the shape was developed by pushing the metal back down where necessary from the front with various hammer-driven chasing and planishing tools.
The pitch gives slightly where it is struck, allowing a depression to be made in the surface of the metal in the shape of the striking tool, but supports the metal enough to prevent deformation elsewhere.
I had neither enough pitch nor enough work surface on which to anchor the pitch and Neptune to be able to fill the entire figure with pitch at once. So I worked only one of five areas of Neptune’s body at a time. Each region was backed with pitch and worked until the shaping of that area was done or, more often, until the iron stretched enough to break away from the pitch. Then the pitch was cleaned off, the iron annealed to relieve the stress produced by hammering, and the form examined to determine the next step. Usually it was apparent at this point that some places needed to be pushed out more from the back. This could be done in some cases over modeling clay but sometimes meant applying pitch to the front and sticking Neptune face down on the work surface.
The process was repeated in each area over and over. Each time the shape was refined and the detail became sharper.
Stress cracks developed in the outstretched arm from vibrations produced by thousands of hammer blows upon the rest of the body. A new arm was formed and welded in place.
To produce the two-sided sturgeon bodies, a die was formed of 2” x 2-1/2” steel bar. Sinking half a body in each side of the die would produce pieces with matching perimeters and flanges which could be riveted together to form a fish body a maximum of 4” deep.
One edge of each oversize pattern was clamped to the die. The metal was heated and driven into the cavity with wooden mallets, pulling the extra material on the free edge into the form to minimize stretching and leave the greatest possible thickness.
The halves of the sturgeon body were planished cold over stakes made for the shell and then filled with pitch for chasing the boney plates on the sides.
A center plate was cut with fins and temporarily bolted between the flanges of the body halves for trimming of the profile. When the fins had been chased and shaped to fit the arch and shell, the interiors of the fish bodies were sandblasted for later paint application, then permanently riveted together.
The heads were forged over stakes, then chased over pitch and fitted to the bodies. Fins not part of the center plate were shaped and fastened to the bodies.
The smaller fish were forged from 1” square iron bar upset to greater thickness at one end and drawn to taper at the other. The bars were flattened on the diamond, the faces forged and the bodies curved to fit the space. Features were chased both hot and cold. Fins were set into chiseled grooves and silver soldered.
"In the process of creating the sturgeon, the large shell, and Neptune himself, Tom estimated that he also created five wood hammers, nine metal hammers and 15 to 20 stake tools specific to this commission."