I. A Look Back
This is actually a misleading title; there was no research done into period methods of casting medallions and the like. The title should (facetiously) read “I. Done by Hand and II. Done by Me” or something equally silly.
What this project boiled down to was this:
Seeking a means to cast a medallion similar to the one worn by the Barony of Hidden Mountain’s Order of the Hidden Mountain, a fighting award, I looked around for materials on hand, as well as ease of construction. I found Sculpey modeling clay for the positive image and RTV (latex plus a stabilizing agent) for the mold. Hidden Mountain’s medallion was bronze, but I wanted to work with pewter first due to its lower melting temperature (600° F. vs roughly 1800° F. for bronze) and generally more forgiving nature. A plan to cast the same medallion with bronze and “new bronze” (has a gold color as opposed to a true “bronze” color) is in the works.
The first medallion was carved out of Sculpey. Fairly easy to work with and it took a good amount of detail. The finished first model is displayed. Note that the Sculpey has been baked (telltale brown color) to harden it for casting. Most of the detail was done with a very small screwdriver blade. Little actual “carving” was done as it was simply a matter of forming the Sculpey in the right locations.
The first mold was poured into a box formed of more Sculpey with the baked original model inside it. Four holes were poked into the box to serve as pilot holes if we ever decided to make a back for the mold. There seems to be no need, however.
After allowing 24 hours to set, the latex mold was removed, the excess latex cut away, and the first actual pewter medallion was cast. The first casting showed quite clearly the disadvantages inherent in using Sculpey by hand; the detail was fine, but the rest of the medallion surface was quite disturbed. Another casting came out cleaner but still with a disturbed texture to the rest of the medallion surface which would detract from the ability to view the centerpiece of the medallion, i.e., the baronial device itself. I am unable to explain the overall gold color of the surface of either medallion but plan to continue research into its cause, since pewter is easier to work with than new bronze. One suspicion of mine is that the material used in place of flux (plain Comet cleanser) may have had some coloring effect. Flux, by the way, is put into the molten pewter to remove the impurities from the metal.
It was also noted that the overall model was quite heavy. The third casting attempted to address this by simply using less pewter and not filling up the entire mold. This seems to have worked.
The third cast medallion was judged to be the best out of the three and was taken to have its surface smoothed off as best as possible. This was to involve the use of a Dremel or other multitool to essentially grind its surfaces flat.
While this was in progress, the question was asked “Why did you do it this way and not use something that would result in a smoother surface to begin with?”
The answer was simple: I was restricted to what was available and what I knew would work. Having never done anything of this nature before, I was unaware of any alternatives.
The alternative is described in “A Look Ahead.”
II. A Look Ahead
The second “original” was cut from sheet plastic, which promised a smoother surface and (theoretically) finer details. Sheet plastic is fairly easy to work with and gave the advantage of being able to be used to make the original in two steps, the first step being to simply cut out a circle of 2.75” diameter, the second being to cut the double-headed phoenix out. These were both done with a combination of a jeweler’s saw and a razor knife. The final work (carving specific details, etc) was to be done with the dremel-type multitool and then the double-headed phoenix was to be cemented to the circle. This was to be allowed to dry, the latex mixed with the coagulant, and the RTV poured into the mold. The pewter was to be cast in identical fashion and the resulting medallion was to be drilled to take two holes to enable the medallion to hang flat on the wearer’s chest.
This medallion was to be much thinner with a resultant substantial drop in weight, and should have had a smoother surface to bring out the detail in better fashion than the first medallion cast. It was of roughly the same diameter as the first, but the double-headed phoenix was made smaller in relation to the surface, thereby leaving more room for additional details to be added to the medallion.
Results
The sheet plastic turned out to be very unfriendly to the dremel, as the plastic heated very quickly and ended up balling up on the tip of the dremel which caused the deterioration of the fine control needed to carve out sufficient details. I suspect that very small leather carving tools such as chisels and punches will be needed to cut off small pieces of the next model, if in fact there is a next model.
After the failure with the plastic and dremel I went back to the original model with a different carving tip and was able to cut out large sections of the pewter, thereby correcting many of the original problems. A followup session with a dremel-sized wire wheel was sufficiently able to smooth off the rough spots.
The resultant pewter model was used as the positive image for another casting with RTV. The RTV mold will be cast (and the resulting medallions should be alongside this paper) with an eye towards using sufficient pewter to save as much weight on the final version as possible.