The 'Hersheys" kiss shape is the filled sprue that gets sawn off and filed.

cate tools to work with pewter so I don’t risk contaminating my expensive silver.

During this workshop several years back, we saw a sample of what Tom called the bologna sandwich casting method.  I was intrigued and saw lots of possibilities for narrow medallion type castings with handwritten engravings, but we didn’t actually see him do one.   Still, I sketched the set up for future brave experimentation.  I also mentioned it to my metalsmithing friends and metors, Mary Kernahan and Lesley DiPiazza as a future workshop subject.  Lesley said she’d look into it through Tom Madden.

Fast forward to summer 2011 during the Ann Arbor Art Fair, where I was exhibiting some of my wares with the Michigan Silversmiths Guild.  Lesley DiPiazza was doing a demo (something I did the previous year before being talked into exhibiting) of the bologna sandwich.  Next to her was Paul Mergen, an expert in metals, who was demonstrating forging.   As her demo progressed, it came out that Paul was the actual person who showed the method to Tom, and that he had learned it from Fred Fenster.

Playing around with the method at casting bootcamp was fun, and I plan to play around some more.  While I still want to mess around with handwritten logos on a charm (trial and error to find right depth, and must be drawn in reverse), my basic outline shape turned out pretty good.  They say it gets a smoother finish after the first few uses, so this has potential.

What you need is 2 thicker pieces of wood or MDF, then 2 thick layers of hardboard.  The inner thickness of our medallion will have the cut out shape of your object and a sprue cut out to pour into.

My first completed wax carving

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.