Experiencing Lost Wax - Preparing to cast metal ancient style

I admitted on social media a couple of months ago that as an undergrad I had misunderstood the “lost wax method” of casting metal, thinking the method was lost rather than the wax. In my defense, the lecturer was a terrible teacher and I wasn’t the only person in the class to make this mistake. A friend from the same class admitted to the same problem after my confession.

For people who are unfamiliar, the “lost wax method” is how the ancient bronze statues were cast. I will go into that a little more below.

The topic came up as I had decided to take a class offered by a friend, Anna-Margot Collins, teaching how to prepare wax for lost wax casting. I had previously taken classes in enameling with Anna-Margot, and immediately thought the opportunity to get a better understanding of an ancient craft was well worth doing. You can see some of Anna-Margot's brilliant work at https://www.facebook.com/annamorgotoriginals/ 

In preparation for the workshop I started scoping out some You Tube videos on wax carving and noticed that modern jewelers use a special wax developed for this method. I knew that in Graeco-Roman times beeswax would have been the medium of choice. By a happy coincidence, I had a block of beeswax in my possession. 

I decided that I would take time before the class to make some beeswax sculpted items and see if I could get them cast along with whatever I crafted in the class itself. 

First I had to figure out what to mould. I looked at various museum catalogues online looking to see what small items were made from cast metal in antiquity. I saw that various charms were common, but many were too intricate for a newbie to try her hand at. Eventually I decided I would try making Heracles' club amulets. I haven't come across many in museum collections, but like many kinds of amulets they do not feature infrequently in antiquities sales (grrrrrr), as I found a few on one site today sold within the last five years. I figured that these were common in antiquity, likely made from casting. I didn't actually see that stated anywhere when I made this decision, but looking at them, I couldn't see how else they might have been; I've since seen it said that smaller ones were cast. This also had the bonus of being not too difficult, as the basic design allowed plenty of room for error. 

I cut off a block of beeswax and started carving out a club shape with a craft knife. I then used my steel artist's scribe to melt small amounts of wax using a tea candle as a heat source to apply the knobs to the club. Carving the club out was annoying. It wasn't particularly difficult, but was not extremely easy. The wax wanted to stick to my blade and was a nightmare to remove. The use of molten wax, however, was mostly easy, but I had been also heating sections on the club itself to assist in getting them to securely attach.

My completed wax clubs and the tools I mostly used.

It was around this time I thought "if I were to mould a few of these, I could show a bit more about the process." 

The finished wax clubs. The club on the right was made by carving the wax.

I gathered my shavings together to place them aside for later use, and realised that items could be more easily shaped like this rather than carved from a solid block. So I smashed these shavings together into a basic cone/club shape. The advantage of using this method was it gave more texture to the club even before I added the knobs of wax. The more the wax was handled, the softer it became, and thus easier to shape. The softening of the wax also meant that I didn't need to melt the basic club to get the knobs of molten wax to more firmly attach. Looking at the three wax clubs above, this can be seen in the smaller amounts of carbon (the blackening of the wax) in the two clubs formed from wax shavings. This softened wax could also be easily rolled out to make the loops at the end of the clubs which could be used to attach the finished amulet.

Once I stopped trying to carve the wax, the process became much, much easier. By shaping the wax with my hands and using molten wax to form the club's knobs, I was pleased with the result. One ongoing problem I did have was I kept smooching my loops and having to use my scribe to re-open the hole. 

A close up of one of the wax shavings shaped club.

I had to call a stop to prevent destroying what I had made. While I had managed to recover my loop holes, I knew that I could only push my luck so much.

So I turned up for my class with my three wax clubs, hopeful that they would be suitable for casting.

And I got lucky. Anna-Margot informed me that beeswax was suitable to the lost wax casting that the casting company in Sydney uses. You must use products which burn or melt away cleanly. If I had used soy wax, for example, it could not have been used. The point of using beeswax was to get an understanding for the ancient process, so I was very happy that they were suited. Looking at my pieces, she suggested that we use the wax shavings pieces as the lesser amount of carbon would make for a cleaner cast. The carbon was likely the result of using a tea candle to heat my tools. In the class we instead used little alcohol burners which release no carbon. Not all waxes are suited for lost wax casting apparently. 

In the class, I was given modern wax to make some jewelry pieces and had the process used today explained to me. My wax pieces would be encased in a mould, capturing the detail, which would then have the wax melted out, and then filled with molten metal.

To best understand how this method was used to create bronze statues in antiquity, a blog, Lost Wax | Journey to Perplexity (wordpress.com), provides this excellent explanation. Unlike my pieces, big statues had a core, often made of clay on which the details of the piece would be rendered in wax. For a larger more legible infographic, click here.

Lost wax method as described by the author of the Lost in Perplexity blog.

 My pieces, being smaller, had no core. In relation to my clubs, Anna-Margot and I agreed that a bronze casting would suit best. Most of the examples I have seen of these were made from bronze, I was extremely happy about that. I requested that one of them be properly finished with pin removed and fully polished, while the other left as it came back from the caster.

My thinking with regards to this was to get a sense of how a bronze piece might have looked straight from the mould without any polishing, in direct comparison with a polished piece. I thought the opportunity to illustrate a wax piece, an unfinished piece, and a polished piece would be interesting. 

And I still do. Here they are.

Left to Right: Wax piece; unfinished cast piece; polished cast piece.

The pin attached by the casters was put on the tip of the club rather than the the loop at the top of the handle which I had incorrectly imagined. 

The tip of the club where the pin was attached for casting. You can see the spot where the pin was snipped off on the middle club.

Without polishing, the roughness of the pin site is apparent. Anna-Margot thinks the casters might have treated the pieces with a chemical bath (I think she said an arsenic bath). Anna-Margot treated the finished club with some time in a tumbler to knock the rough bits off, a little bit a file on the end, and a thorough buffing on the buffing wheel. The difference this makes to the colour of the bronze is amazing. I personally prefer the colour of the unfinished piece.

So what has this told me about the craftsmen of antiquity who used this method?

The amount of detail you can get just with wax is amazing. I was unsure what to actually expect, but was pleasantly surprised. While it isn't immediately apparent in my clubs, a piece I made from modern jeweler's wax shows just how tiny lines can be captured in this medium. 

A silver toadstool which I fashioned in wax during my class.

The scratches on the stalk came from simply running a pin tool down the length of the wax. Looking at that, I can see how easily the detail of things such as the boxing gloves of the "Boxer at Rest" held in the Palazzo Massimo alle Terme in Rome could be rendered.  

Photo by Carole Raddato (Boxer at Rest - Wikipedia)

While the softening of wax made it easier to shape into my clubs, I think is is fair to say that the working of the beeswax by ancient artisans took place nowhere near a forge or any heat source used for the preparation of actual casting. Using heat judiciously can help smooth out your wax, you need the wax to hold its form to keep your details. I doubt very much they even worked with wax on a hot summer day. I would guess this was the work of autumn through to spring where heat could be applied only as an artist wanted it. I do not know what method these artists used to heat their tools or whether carbon was seen as their enemy.

While making my little amulets were easy, as were my silver pieces, this class gave me a further appreciation for the artists of antiquity. There is a hell of a difference between working a small amount of wax into a desired shape and smearing it over a life-sized figure core and giving it the necessary details; I couldn't even keep a loop hole open. Yes, changes could be made to the bronze after casting, but it would have been far easier to work with the wax to render the details of the boxing gloves you see above. You would get greater precision that way than trying to engrave details into the metal afterwards. Ancient artisans were amazing, and I never fail to be in awe of their skills, especially after I try to get a better understanding of them.