Tim Cotterill showing one of his large bronze frog sculptures

The Frogman Foundry

So, it’s no surprise that, these days, it’s a team effort to get Tim Cotterill sculptures out there – and Tim, aka the Frogman, is always keen to pay tribute to his colleagues at the Frogman Foundry in Southern California, especially for the remarkable patinas that set his pieces apart.

Tim Cotterill foundry
“Our patinas are mimicked by every other foundry,” he says. “Until I came along, everyone used museum brown or verdigris green. 

“In the late 90s, I asked the foundry to come up with something new – they came up with the most beautiful colours! They’re experimenting all the time. I tell them what I want; they send me four or five samples. We’ve worked together for so long, I can just tell them to go wild!”

Located in Southern California, the Frogman Foundry combines cutting-edge manufacturing techniques with unparalleled attention to quality and finish, with each sculpture demanding 200 to 300 hours of specialized production. 

Tim Cotterill outside his studio

Each frog starts as an image in Tim’s head, which he then sketches before making a master, welding a metal armature to which he applies his chosen medium – car filler!  

Tim refines the design, painstakingly shaping it with steel files, then sends the model to the foundry, which uses a process dating back thousands of years – lost-wax casting.

A flexible silicon mold of the sculpture is made, then sheathed in plaster for strength and rigidity. When the plaster dries, the mold is pulled apart and the original removed. The mold is reassembled and hot wax poured into the cavity to make a duplicate of the original sculpture. 

This version is dipped into a liquid slurry which starts to build a ceramic shell.  Over several days, successive coats are applied, each one taking a day to dry. The result is fired in a kiln to create a hollow mold (this is the bit where the wax is ‘lost’!), which is then filled with molten bronze to create the sculpture. 
Once smoothed and polished by hand, the sculpture is ready for its shimmering patina, created by the application of heat to various chemicals – and, like everything else in the process, hand-done, so no two frogs are exactly alike.

Tim Cotterill showing his handmade bronze frogs

Finally, a clear sealant is applied and the sculpture is hand-buffed, then each limited edition sculpture is signed and numbered by Tim Cotterill himself.
The final sculpture, whether a tiny, jewel-like tree frog or a giant version, is hugely collectible – and keep an eye out for a new one every couple of months!
Interested in finding out more about what makes a Frogman bronze so special? Check out our Art blog or shop the full Tim Cotterill collection online at the Artmarket Gallery
With opportunities to purchase bespoke commissions and extremely rare pieces – get in touch with one of our expert art consultants today and find the perfect addition to your home.

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