Polygel® Spray-On Mold of 19-Foot Tall Mastodon Sculpture

Kent Ullberg is a highly acclaimed wildlife sculptor whose work spans the globe and can be found in numerous museums, municipalities, corporate offices, and private collections. Ullberg is well-known for his monumental works, which include a 23-foot-tall elephant (installed at the St. Louis Zoo) and an 18-foot mako shark (installed at NOVA Southeastern University), among many others [www.kentullberg.net].

According to the Reporter-Herald, Ullberg’s most recent monumental sculpture, a 19-foot-tall, 24-foot-long mastodon, is a scientific reconstruction based on findings by scientists from the Denver Museum of Nature and Science, the Smithsonian Institution (Washington, DC), and a Michigan university [www.reporterherald.com].

The Molding Process

The bronze casting process was completed by Art Castings in Loveland, CO. Spray Solutions, also located in Loveland, stepped in to create the rubber mold of the sculpture (one of the early steps in the casting process).

Spray Solutions utilized Polygel® Spray 35, a self-thickening, two-part (1A:1B mix ratio) polyurethane rubber, to make the mold. Because the sculpture was to be cast in 100 separate pieces, aluminum and plastic shims were strategically placed in order to construct the mold in 100 separate sections.

Polygel Spray 35 was applied to the clay sculpture with meter-mix spray equipment.

Some of the behind-the-scenes work can be seen below [photos courtesy of Sculpture Depot]:


Mastodon Sculpture - Shims




Kent Ullberg Mastodon Sculpture Mold




Monumental Mastodon Sculpture




Polygel Spray On Rubber - Mastodon Sculpture




Polygel Spray Polyurethane Rubber



Ullberg’s mastodon will arrive at the Denver Museum of Nature and Science at the end of September and the dedication date is late in October.

Visit Kent Ullberg’s website for biographical information and more examples of his work.