Our Cold Casting Process
Casting Overview
Our switchplates are made in a cold cast metal technique chosen to best replicate the fine detail of the hand sculpted clay originals at an affordable price. The casting material is 80% metal and 20% resin, a ratio that optimizes flow into the molds and provides the integrity to modify the face with sandblasting, acid oxidized patinas and finish indistinguishable from 100% metal. The finished switchplate is noticeably lighter in weight than would be expected from a full metal casting—a feature that is essentially "invisible" when the switchplate is installed and, again, the result of a choice we made to best fulfill our design intent and our commitment to a product designed and manufactured in the USA (Phoenixville, PA).
You will also notice that the back of the switchplate looks different from the front—more "plastic." Although the casting mixture is thoroughly homogenized when poured, there is enough time in the curing process for the heavier metal content to settle downward toward the face of the switchplate and away from the back of the plate. Rest assured, the beautiful finish you see on the face of your metal switchplate is not a mere paint-thin coating.
The only other casting process that would preserve both the sculptural and finer textural qualities of our original art in 100% metal is lost wax casting, a much more costly method. Plates made with this technique would be approximately two times the cost of those we offer here.
More detail about our cold casting methods and final hand finishing follow below.
More About Cold Casting
To review, the concept becomes a drawing which is translated into the third dimension via hand sculpted clay, from which a mold is made. The mold is filled with the 80/20 mixture of metal and resin. The next step is curing.
The casting is cured, still in the mold, locked into an air tight pressure vessel under 60 pounds of pressure per square inch for one and one half hours. Together, the metal/resin mixture and pressure curing, capture the most extraordinary level of detail; better than any other process available. Next, we remove the casting from the mold and allow it to air cure for at least one more day.
From Casting to Blasting
Once fully cured, each casting is lightly sandblasted with 180 grit aluminum oxide powder to fully expose the metal for the acid dip stage.
The Acid Oxidized Patina
Dipping in acid is the next step—it is used to greatly accelerate the ravages of time that give metals the aged patinas we so prize. The darkened patina beautifully accentuates our sculpture.
The sandblasted plate is dipped in an acid bath and gently hand brushed until an even charcoal gray patina is achieved. A quick rinse is followed with forced air drying to prevent water spots.
Steel Wool—The Final Handwork
We begin this final stage with a switchplate whose beauty is masked by the uniform gray patina from the acid bath—beauty beneath the soot of manufactured time.
Skilled hands take a small wad of quad zero steel wool and, guided by attentive eyes, patina is removed from the higher sculptural features and left untouched in the lowest recesses to accentuate the details and textures. More or less patina is removed to achieve the desired finish—less patina is removed overall in an oil rubbed finish versus an antique finish.
Some areas revealed by the removal of patina will be further highlighted by additional polishing, again with fine steel wool by hand. The brightness of these polished features will vary in each of the chosen finishes.
These final steps are preserved from further oxidation by a coat of protective lacquer.
After the final handwork
If a plate breaks, we'll replace it.