Appendix 1: No, it wasn't Lost Wax Casting.

 The following is a draft of one of my appetencies. 

Pisano almost certainty knew about the technique of lost wax metal casting.  It is arguably the second oldest form of metal casting known to human kind, and is still used today in multiple industries and arts. 

However, it is also an irrefutable fact that none of the metalwork that Pisano did as a famous and groundbreaking medalist had anything to do with lost-wax casting what so ever. 

Why am talking about this? 

Because the moment I say the words "Bees' Wax" in a class or presentation, someone jumps to 'oh, this must be lost wax casting then', and I then need to stop what I am doing and spend the next five minutes explaining that not only does this having nothing to do with lost wax casting, but that even mentioning lost wax casting only confuses people needlessly. 

So for the sake of clarity, lets take a minute and set this misconception to rest. 

Lost wax casting dates to some of the earliest civilizations, with artifacts discovered in Asia and the Middle East that date back over five millennium. 

In his paper, Hunt (1) summarized the broad strokes of the likely origins of this casting technique.

At an unknown date somewhere in the middle of the fourth millennium B.C. — again possibly independently in more than one region — either a potter or a metal worker, or more probably the two working together, conceived the brilliant idea of taking a model carved in beeswax, coating this with clay, heating the composite structure both to harden the clay and to melt out the wax, and then using the mold so formed to produce a more complex casting with every detail carved or built up in the wax.

There is no disputing that the basic concept of lost wax casting was revolutionary in its time. And I don't want to take away from its significance as a historical turning point for human civilization. It was all of these things, and more, if we're being honest.

But, there is something very important in Hunt's summary above that we need to highlight here. 

"Heating the composite structure both to harden the clay and to melt out the wax."

In this process, the original model is destroyed in order to make room inside the mold itself for the metal. The wax was literally 'lost'. It didn't just melt away, with the type of heat needed to harden clay, (2) the wax would have been vaporized and possibly even ignited, depending on how fast the mold is heated.(3) 

With lost wax casting, if anything goes wrong, or if the final product does not come out right, the artist is back at the very beginning; making a new model.

From scratch. 

This is not how Pisano cast his medals. And it is highly likely that the 'all or nothing' nature of lost-wax casting was a good portion of the reason why no artist had successfully used the technique to do the type of  work Pisano was made famous for. The sand casting technique that Pisano helped to discover in Europe would allow him to do a test cast in lead while keeping his model at the same time. If the resulting cast wasn't up to his standards, he could go back to the model and make changes in the sculpted bee's wax on his model, and then do another cast. 

Additionally, sand casting something like a medallion would inherently be cheaper and easier than lost-wax casting. In both processes, the model has to be made, and the metal has to be melted. But in lost-wax casting, you also have to heat up the mold itself to extremely high temperatures, and keep it at those temperatures until the clay around the model is fully hardened. This process represents time, and cost in fuel that simply does not exist in sand casting.  

I can say from first hand experience that it takes about 15 minutes to make a sand mold for a medallion. After that its immediately ready to pour metal into. 

Even the smallest clay item has a firing time measured in hours, and then a cooling time also measured in hours. (4)

Without even taking into account the details of kiln types in period, fuel sources, the physical dimensions of the item being cast, or the metals, in a one-to-one comparison, lost-wax casting is inarguably slower and drastically more expensive option when compared to sand casting. 

And this compounds with that fact that if anything is wrong with the cast, both the model, and the mold are destroyed by the casting process in lost wax. 

If you don't like the final product, you are starting over.

Again: from scratch.

These two facts are more than likely the key reasons Pisano didn't use lost wax casting for his medallions. 

1. "The Long History of Lost Wax Casting. Over five thousand years of art and craftsmanship". L.B. Hunt (June 1980) https://www.smpub.com/ubb/images/18/10-0607-lostwax1.pdf

2. SDS industries website lists earthenware pottery as reaching optimum hardness between 1745 degrees F. and 2012 degrees F.  https://www.kilncontrol.com/blog/kiln-firing-chart 

3. Honeybee.org lists the flashpoint temperature (the point at which its will ignite without an external flame) of bee's wax at 212 degrees F. https://bee-honey.org/is-beeswax-flammable

4.  Kilnfire.com lists firing times of  small items starting at 4 hours, and larger amounts of clay only push that number up. https://kilnfire.com/blog/how-long-to-fire-clay