From a tiny 12 inch wax model to a giant 8 foot bronze monument in a zillion not-so-simple steps.
When Gary Roller visited Yogananda Gardens at the end of February we checked out two Portland area art foundries that together could fabricate the large statue of Paramhansa Yogananda that will be the centerpiece of the World Brotherhood Plaza within the gardens.
First we visited the Maiden Foundry in Sandy where owner Mike Maiden showed us through the facilities and explained the process by which he takes a full sized sculpture in wax or clay and creates its duplicate in bronze metal. Molds are created using rubber covering sections of the sculpture supported by an outer shell of plaster. These are used to make wax positives with channels added (sprues) that allow molten metal and air to flow. Even a funnel for filling is included. Then they dip these pieces in a succession of ceramic slurries to form a shell which they then fire to harden the ceramic and melt out the wax. They will pour molten bronze into these molds, let it cool and then break away the ceramic shell to reveal the bronze. They then weld all the pieces together and polish it up.
The finished bronze can be colored by heating one section at a time and spaying with a chemical patina. Finally they apply a wax coating. We saw many vary beautiful pieces of their work in progress. When I asked about outdoor use Mike told me that it only requires an annual waxing to maintain the color. It was interesting to learn that the bronze is actually quite thin with an estimated weight for our eight-footer of only about 400lbs.
But how to we get from 12 inches to eight feet?
A few days later Mike Maiden took us to an amazing place in Portland called Form 3D Foundry where CEO Rob Arps showed us how to do this.
According to the teachings of Yogananda’s guru Sri Yukteswar, we have now progressed to an age called Dwapara in which we have achieved control over material form and are starting to work on taming space. Nowhere is Dwapara’s control over form more abundantly evident than in this 3D foundry.
The story of growing our statue can go something like this: First, the 12 inch model is laser scanned from several angles. On a computer the scans are assembled into a 3D digital model which can be scaled up to any size. For us the first step is to a four-foot version. Since the computer now has the sculpture, it can compute a mold around it. This mold is then 3D printed in pieces in a huge machine that can create parts up to 3 feet long with detail to 1/600 of an inch. We watched it at work, spreading a very thin layer of plastic powder over a large area. Then a print head made its way back and forth spraying glue here and there according to computer directions.
When the whole area is covered a new layer of powder is spread all over and the process repeats. In the end a whole bunch of pieces of molds are to be found embedded in the loose powder. These pieces will be glued together to make the new mold which contains all the detail of the original enlarged to the four-foot size.
The next step in this inside-out world is to line the mold with clay and then fill in the hollow with foam that solidifies to form a rigid structure – quite the opposite to the normal way of creating a sculpture. When the mold is removed and the pieces assembled we will have a precise enlargement in clay ready for the sculptor’s finishing touches. We saw some figures at this stage created by scanning live posed people. The result was so real looking that artists were hard at work putting fake tool marks on the work to make it look more like a sculpted piece! Rob told me that all of his employees are artists!
Once Gary adds detail and makes adjustments to the four-foot version, the process will start all over with a new laser scan, more 3D printed molds plus clay plus foam resulting in the eight-foot “original” that can be sent over to the Maiden foundry for creating the final bronze piece. Whew!
A four-foot version of the Yogananda statue?
A by-product of this two-step enlargement process is the possibility that the four-foot model could be used to make multiple copies in that size. (Let us know if you might be interested in having one of your own.)