Well, class is over and my bronze sculpture is complete. This past Sunday, I sandblasted my sculpture to clean and open the bronze up for the application of our patinas. Patinas are chemicals that react with the surface of bronze by changing its color. This process is similar to what naturally occurs when bronze is exposed to elements over much longer periods of time.
We could choose from black, brown, and green patinas. The patinas were applied in what is referred to as a hot process, which means that the bronze was torch heated before the patinas were brushed on. A cold patina process, patina applied on unheated metal, is typically used on decorative hardware like most of Shop 4 Classics bronze vent covers. I found the hot patina process cumbersome because I had to maneuver a gas fed torch in one hand and a patina brush in the other. After the patina was applied, I scrubbed my character's arms, legs, and head to once again expose the true bronze. Similarly, true bronze hardware has what is called a “living finish” because the color of the bronze changes as it is exposed to the elements. When bronze hardware is rubbed, the patina will wear exposing the typically golden yellow bronze. Patina will rub off of frequently used bronze cabinet knobs and bronze door knobs showing the true color of bronze. For most, this wearing off of the patina is appreciated as it adds character to the knob.
Classic Grills provides a good example of how patinas can be applied to produce different looks to the same product. Classic Grills offers the same bronze vent cover grilles in black and brown patinas. Visit our Finish Tips for more information of hardware finishes.