Process

Conceptualization & Creation-

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

Mold & Pattern-

To mold, we evaluate then prepare the original piece to be molded. We define the type of mold needed then go to work and make anbook mold or art mold depending on the piece. 

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

Once the mold 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 mold to produce a pattern. Once the pattern is cooled, the mold can be pulled apart producing an exact replica of the original object. The pattern is then tooled small hand tools & wax filler to fill any imperfections.  

Cup & Sprue-

This is the part where things start getting interesting. Now that a pattern of the original piece is on the table, it's time to begin the process of creating a structure that the piece can be attached to, and eventually transformed into metal. The structure is created using dimensional microcrystalline wax stock called sprue. The sprue is attached to a 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 and 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 and 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 waxes are used in this final step.