West Side Stone Works of Macon, Georgia took on a mold making and casting project to create cast stone magnolia buds that would serve as finials on the columns situated at the entrance of Tattnall Square Park in historic Macon. Local artist Amy McCollough Hellis sculpted the magnolia buds from clay and West Side Stone Works took over from there. The original sculptures are approximately 3 feet tall and 20 inches in diameter.
Here are pictures of the original magnolia buds at varying angles:
[all photos are courtesy of West Side Stone Works]
Because of the significant undercuts on these models, West Side Stone Works utilized our most flexible polyurethane mold rubber, Poly 74-20.
Basic Specifications: Poly 74-20 is a Shore A20 polyurethane rubber with a 1A:2B mix ratio, 30-minute pour time and 16-hour demold time.
Poly 74-20 is a pourable rubber with low viscosity. To make it suitable for brush-on application, they thickened the liquid rubber with PolyFiber II, a shredded fiber thickening agent. They also accelerated the cure and demold time by adding Poly 74/75 Part X Accelerator.
Prior to brushing on the liquid rubber, Pol-Ease® 2300 Release Agent was applied to the models so the cured rubber would release well from the clay when demolded:
This is a picture of one of the cured Poly 74-20 brush-on molds prior to mold shell construction:
Because brush-on blanket molds are thin, a mold shell is required for support. West Side Stone Works decided to use Poly 1511 Liquid Plastic with PolyFiber II thickening agent to make their multi-part mold shells. They used clay to make shims for this process.
Upon cure of the plastic, the rubber mold and mold shell were removed from the model to prepare for casting. The picture below is a view of the interior of one of the finished Poly 74-20 molds:
After cleaning the molds and placing them back in their mold shells, a concrete mixture was poured into them. The final pieces are shown below prior to installation:
Finally, the cast stone magnolia buds were installed atop these columns in Tattnall Square Park as part of a revitalization effort:
West Side Stone Works is located in Macon, GA and can be reached at 478-474-8585.
Do you have an upcoming mold making or concrete casting project you would like to discuss with a Polytek Technical Support staff member?