A Journey Through the Creation of a Plaque

A Journey Through the Creation of a Plaque
By Drew Williams & Keith Williams

As a special treat for our regular visitors, we have decided to share the process of making a plaque here at Drew Williams Sculpting Studio. Although there are many fine plaque engraving services available, most of them overly rely on computer technology templates and lack the trained expertise to render an original image. For bronze casting our studio works with the fellows at New Arts Foundry in Hampden, MD. New Arts Foundry is one of the finest casting foundries on the east coast.

On this page we will give you stage by stage snapshots of a plaques development. Here we will show our work as subcontracted by the people at Valent Studios in Vestal New York, for the Lynn Plastics Co. This will be a recognition plaque, featuring a deep relief image of the Lynnco founders with some text at the bottom. The final casting will then be mounted on a finished piece of hard wood by the people at Valent Studios. The overall size is much smaller than most plaques, with a very detailed image area. This is our expertise!

The plaque started out as a carefully compressed slab of Chavant NSP Hard clay. This clay is the same material used by auto designers, and was needed here to keep the edges sharp and prevent shifting of the art while it was being worked on. It was planed flat and trimmed to the dimensions of the planned size. Extra thickness was added to ensure the sculptures stability during handling and transport later on. Large tools were used at this stage, including our machete which can be seen in the background.

Next a scaled copy of the original photo provided by the client was placed on top of the clay along with planned borders. A needle was carefully driven through the paper into the clay to establish the borders of the major shapes in the image.

After the general shapes are located, the clay is removed in layers, with different planes for the bas relief laid out. A map of how the different levels tuck into each other is carved, weaving the bas relief illusion, along with foreshortening, logistical puzzles abound. Since the persons in the photo were all looking towards the viewer, it became necessary to make deeper cuts into the background, so that more transition could be allotted to the subtleties of the faces. Without this extra room, the likeness would become more distorted and the illusion of depth would fail.

Basic features and details in the models and background began to take shape, and much of the bas relief plane depths were finalized. An impression of the background is carved out. Since both the faces and hands should be the most important features within the image, they are given more prominence with some added relief. This is the rough stage, and is jokingly referred to as the 'doughhead' phase by the staff.

Later the details and facial features were either carved out or built up, and the background is clarified. We sharpened up the shelves and accentuated the angles that would describe their perspective, but also shallowed them out more, to keep them from overwhelming the deeper foreground details.

The details are resolved to near-completion, and problems regarding individual likeness were attended to. The detail of the books on the shelves in the background are given more attention, but are still left slightly vague so as not to compete with the figures in the foreground. Textures are added to areas that may eventually hold more of the darker colors when the bronze is treated. This will help create better contrasts and highlights.

As stated before, the greatest difficulty with sculpting in bas relief is rendering the illusion of full depth within a limited space. As you can see in this close-up of the figure on the right, although the likeness was becoming more accurate when seen from the the front, the sculpture became remarkably distorted when viewed from the side. For this reason, many plaque portraits are more often resolved in profile. The subtleties of the foreshortening process in bas relief often plagues many otherwise qualified sculptors.

Next we use a fresh razor to carefully shore up the precise edges of the surface plate. We opted for a 1/8th inch thick sheet of polystyrene to place on the top of the finished art. This helps save development time and helps to achieve an instantly clean 'machined' surface with the least effort.

Our 1/4 inch thick magnesium die text plate was finished and mounted into its place on the polystyrene sheet, which was, in turn, affixed to the clay. The remaining clay sides were carved flush to the precise edge of the new surface plate, and final touches on clay details in the image were done. The remainder of the details in the image area would be further clarified in the resulting wax as well as the eventual bronze.

The surface of the plaque is prepared with a spray silicone lubricant so the mold can peel away once cured. A catalytic rubber is carefully poured over the original sculpture as it rests at the bottom of a prepared box. It is poured in the corner very slowly to prevent air bubbles from occurring, which would show up in the finished mold.

After the piece is fully submerged in the liquid rubber, it must set for 48 hours. Although dark green in its liquid form, it will eventually cure to a light beige color. This stuff is rather toxic, and produces some nasty fumes.

Once it's dry, the molding box is turned over and the plaque is pulled away. Once the original sculpture is safely removed, the rubber mold can be pulled out. Here's what the rubber mold looks like in "negative".

Here is a close up of the negative impression of the design. Careful inspection is made for air bubbles, especially around the letters on the commemoration plate. If any air pockets obscure the image, it will need to be repaired in the wax phase.

Yes, the wax is messy. Very messy. But quite functional. The wax is melted to temperatures over 200 degrees in these pots. Notice the thermometers sticking out of the tops.

The mold is sprayed with silicone lubricant again. Rather than simply poured, the molten wax is first carefully painted into the details in the rubber mold in three successive layers. This is to prevent bubbles of air from coming between the wax and the rubber.

Extra warm dabs of wax are added by hand over raised areas and ridges of the piece. This is to leave the wax at a uniform thickness.

A second batch of inferior reclaimed wax is used to fill out and reinforce the more carefully laid layers. The temperature is about 180 degrees: hot enough to pour in, but cool enough not to melt through the previous layers of wax down to the details below.

The excess wax is poured off. What remains will cool off completely over a couple hours before it can be removed and handled for retouching and eventual gating.

Once the wax is pulled from the mold it is retouched with dental tools and needles. The darker reclaimed wax can be seen just below the translucent surface in some areas. Now that the wax has been cleaned up and prepared, an assortment of wax 'rods' are added to the back and side to create the channels the bronze must pour through.

The wax is dipped in a fine clay-like slip, and then immediately covered with an equally fine layer of sand. This process is repeated several times in layers to create a durable shell.

The first layers are hung to dry. Once they are thoroughly hardened the process begins anew with even more layers of slip and sand, but of increasingly coarser grades which will give it durability.

After the shell has been cooked off the wax has been melted out and all that is left is the mold itself. Still glowing hot, it is quickly placed in a sturdy metal sand bin, and positioned with the pour opening facing upwards.

Foil wrap and tin pans over the openings prove handy for keeping the sand from accidentally getting into the mold cavity.

All the while, the crucible of molten bronze has been heating to just the right temperature. Very careful measures are taken at this point.

The pour itself. Metal tongs holding a crucible of molten bronze can be quite heavy, hot, and difficult to handle. Cooperation is key.

The crucible is set down as the new pours begin their cooling process. It takes only a few hours before the mold can be broken off and discarded like so much unwanted plaster.

The casting itself! Untreated, it is still a little rough around the edges, but thankfully the pour was a complete success in every way. The sides are machined smooth, minor 'bubbles' that remained caught under the first slip coating, are discovered and tooled away.

The final touches to the metal have been made! The plaque is stained with a patina to bring out the textures and forms, then buffed to a nice smooth appearance. A thin layer of wax sealant is applied to prevent corrosion and discoloration over the years, and bolts are welded to the back for its mounting.

Here's the final product! It has been mounted on a richly colored wood, and is ready for presentation to the recipients for display for years to come.

If you have an interest in commissioning us to sculpt a likeness for a plaque or other bas relief metal work, feel free to e-mail us or call us and we can discuss a price quote and work schedule. Visit our Contact Page to get in touch with us.