Conceptualization & Creation-

First we begin with an original object. Our original is either a natural, sculpted, or 3D printed object. Sometimes a combination of all 3 mediums. 

Mould & Pattern- 

To Mould, we evaluate then prepare the original piece. We define the type of mould needed, then go to work to make a book or art mould depending on the project.

A typical mould is a two part encapsulation of an object that is then separated. This the original object to be removed leaving an exact negative replica of the original object.  Mould making is an art in & of itself. The techniques required to take a unique object, capture all of its detail, & produce a functional mould capable of producing hundreds or even thousands of patterns takes years of practice to master. 

Once the mould is complete it's time to pour or inject the first pattern. This is done by heating microcrystalline wax to 180° +. Once the wax has reached temp, hot wax is poured into the mould to produce a pattern. Once the pattern is cooled, the mould can be pulled apart producing an exact replica of the original object. The pattern is then tooled with small hand tools & wax filler to fill any imperfections.  

Cup & Sprue-

This is the part where things get interesting. Now that a pattern or patterns of the original are on the table, it's time to begin the process of attaching to a cup & sprue structure. The cup & sprue structure is created using dimensional microcrystalline wax stock called sprue. The sprue is attached to a wax cup that forms the base of the structure. A vertical & horizontally supported sprue structure is then created to sufficiently support & space the patterns. The patterns are then attached to the sprue. The structure will allow bronze to be poured into the cup, flow into the sprues, then into the patterns, creating an exact replica of the original molded piece. 

Slurry-

The cup & sprue structure can now enter into the slurry process. Slurry is a colloidal silica binder, fused silica, refractory materials , fused silica, water, polymers, wetting agents & anti-foam agents. The cup and sprue is dipped into the first coat of slurry. The first coat is the finest, encapsulating the smallest of details of the pattern.  The subsequent slurry coats are more coarse. Multiple coats are built up around the cup and sprue to form a strong shell. The top of the cup is left open & not coated with slurry for the next step. 

Burnout-

The slurry coated cup, sprue, and patterns are now ready for the next step in the process, burnout. The shell is now flipped over so the structure rests on the cup. The shell is placed in a burnout oven and heated to between 1,100° and 1,500° to burnout and vaporize the wax cup, sprue, and pattern structure. After cooling, the end result is the slurry shell that remains intact with all wax melted or burned out. This is how the "shell" is created representing an exact replica of the wax cup, sprue, and patters that were once inside. 

Pouring Metal-

Shells are loaded  into a kiln and heated to between 1,000°-1,200°. Bronze is also heated in a crucible until molten, typically between 1,900°-2,100°. When the bronze  is ready to pour, the shells are removed from the kiln, placed in a sand based pouring trough, and molten bronze is quickly poured into the cup of the shell until full. The bronze flows through the cup, to the sprue, and permeates the cavity where the negatives of the original patterns once were creating an exact bronze replica of the original pattern. Pretty cool right?!

Shell Removal & Blasting-

Once the shell has cooled, the shell is mechanically removed with hammers & air hammers revealing the cup, sprue, and patterns now seen for the first time in their new form, bronze. The bronze is then sandblasted to remove all slurry materials and leave only the bronze. The patterns are cut off of the cup and sprue.

Milling, Drilling, Tapping-

Knobs and pulls are now ready to be faced milled in a knee mill. The appropriate drilling and tapping is performed, typically to an 8-32 diameter and thread pitch.

Tooling-

At this stage, any imperfections in the metal like pits, divots, or shell is removed and repaired. The piece is then sanded to ensure that any mold or registration marks are removed, as well as any sharp edges or burrs. Die grinders, angle grinders, pencil grinders, tungsten carbides, cross pads, and sanding discs are used to achieve the required end finish specification. Grits range from 80-320. 

Patination-

The final step in the process, patination. Chemicals & minerals are used to achieve an array of colors from a classic patina to an array of vibrant colors. First, the bronze is heated with a propane torch by a Patina Artist. The Patina Artist then sprays different patina agents on the piece while hot, rapidly oxidizing the agents, producing intended colors and patterns on the piece. Once that patina is complete, the piece is sealed with a topcoat to lock in the patina. Cerakote, marine grade clear coat, or wax is used in this final step.