Picture a nice day in August 2011.
With little sleep the night before, I was able to concentrate quite well by sheer desire. I’ve made a low temperature 2-part rubber mold and a higher temperature see-through silicone rubber mold (RTV) for lost wax casting in the past. I’ve experienced freeform casting, open casting with pewter, cuttlefish bone casting in pewter and fine silver at least once each. But this bootcamp with Lesley DiPiazza and Mary Kernahan was a chance to get more perspectives on process, practical hints, creative ideas & more. By doing a few new things and repeating some of my earlier experiences, I hope to find ways to modify the necessary materials and protocols to do the PILE of items I’ve collected that I want to cast.
One area I have very little experience in is custom wax designs. There are 2 basic approaches here — carving wax away from a block like a sculptor, and adding wax to a form, creating shape and as much detail as possible by adding softer wax. The latter seems perhaps a bit more forgiving of mistakes. (a matter of opinion, skill, experience and perceived enjoyment). More on this later as we start tomorrow to discuss the various hardnesses of waxes, tools and techniques. I think we’ll be attempting a ring by the end of the week.
Our first day, we did an overview of bronze and silver properties as they pertain to melting for casting. We went on a little journey for some found objects from nature to cast, and chose a couple of small plastic items to prepare for investment (a plaster that covers the wax object, natural material or small plastic piece). We learned how to branch a wax sprue at the most advantageous point to allow the metal to fill the entire cavity during casting. We talked about how to arrange as many pieces in the container while leaving proper space to make a strong plaster cast.
The plaster that fills the casting flask has to be vacuum pressurized to get rid of air bubbles two times, left to set, and then fired in a kiln to burn out the wax or original organic matter so that all that’s left is the cavity of each item that will be filled with molten metal during the casting.
Pictured is my first completed product from my wax carving that was cast in Fine Silver. I am having a professional mold made of this so I can reproduce it and alter the wax to size it up. I also have a few variation planned, such as engraving in the top, gypsy setting one or more faceted stones in the ring, and hollowing out a reservoir in the top to do inlay of crushed opal, etc.