An outdoor living spaces contractor-landscaper in Texas got in touch with us about making a sculpture for a client’s water feature. She wanted a spitter fountain in the shape of a Corgi dog head, with water flowing through the mouth.
We decided the sculpture would be about 12 inches tall. We would make an HDU foam and water based clay model, make a urethane mold of the model, and cast it in GFRC (glass fiber reinforced concrete) with a tube embedded for the water fountain.
First, I routed the pieces out of HDU and laminated them together to carve the model core.
I sculpted the rest of the head over the foam core with a water based clay. I then sealed it with a shellac spray.
Now the model is ready to make the mold! We used Smooth-On’s Brush-On 40 for the urethane rubber part of the mold. It’s a two part formula that’s mixed together and brushed on in thin layers.
Once it was thick enough to hold detail well, we added on plastic dividers called “keys” that will keep the reinforcing mother mold pieces separate. (If the mother mold was all one piece we’d never be able to get the mold off tricky places with deep angles like the ears and nose.)
We “greased” the keys with a brushable paste wax called Sonite. This keeps the sticky paste that dries into the mother mold from sticking.
We used another Smooth-On product called Plasti-paste for mother molds. It is thick (we apply it wielding popsicle sticks like spatulas) and dries within minutes into a hard, fairly lightweight shell. The mother mold is just a shell to hold the floppy urethane mold.
Next, I prepped the mold to pour the concrete. I brushed a concrete release agent into the mold and set up the tube to the mouth.
Then we poured!
Done! The client wanted it unfinished, natural concrete, so we shipped it off…
But since we had this great mold sitting around the shop, we decided to have some fun with it! We made a bronze resin cold cast, which means that there is bronze metal powder mixed into the resin before it’s poured. Afterward we buffed it with steel wool, which brings the bronze to the surface and makes it look very realistic.
Thanks for looking! Do you have an idea for a special pet memorial or sculpture? Get in touch at our Contact Page!