Being blessed with an unusual amount of free time early this year, I was able to take my time on the design and manufacture of this year’s CanadaMark Diamond Design Competition. I thought it might be interesting to some to see how this year’s contest piece was put together. Bearing in mind that there are huge gaps that are not shown, it may give some insight into the process.
Being platinum, the piece starts as a bunch of rough grain or bar as it comes from the refiner. Actually, the piece starts as a picture in my head, but that’s going back a bit far in the process for our purposes here. These chunks of platinum are welded together at about eighteen-hundred degrees C, so welding goggles are worn and all precautions taken against setting fire to one’s actual self or anything else in the vicinity. It’s impossible to melt platinum into any sort of mold to form an ingot with the primitive tools that I have on hand, so the material is melted into what is technically referred to as a Smartie (an M&M in the US, I suppose).
The Smartie must be flipped over and remelted a couple of times to ensure an even melt, as platinum has a remarkably low heat conductivity. This means that, even if you have the top surface all hot and melty, the bottom remains stubbornly solid. This is kind of good, in that the little ball of molten metal would surely roll off the ceramic fire-brick and burn through nearly anything it touches. Did I mention that it was hot?
The Smartie is taken off the ceramic with tungsten tweezers before it cools down enough to fuse to the surface, some of which has itself melted in the intense heat. It is then rolled down to an appropriate thickness, in this case about 2.75mm which is the depth of the diamond that we’ll be setting in it. Some guidelines are layed out on the surface based on the mockup that I made in wax. Best to waste wax while experimenting rather than using up a lot of sweat and valuable metal. A hole is drilled and burred out to the diameter of the diamond and a triangular graver used to begin opening up the shape of the maple leaf. It starts out looking like the symbol of the 1967 Centennial symbol, which is appropriate, I suppose.
The shape of the opening is fine-tuned according to the practice wax and then it’s ready to be separated from the surrounding material. I like to cut out the hole so it’s perfect, then remove the excess because it is way easier to do this if you have something to hold on to during cutting. Then, it’s a simpler matter to cut and file the excess so as to leave a very delicate frame around the stone.
This seems to be a waste of time and platinum at first, but I wanted to use the material in its as-rolled, work-hardened condition to preserve the strength. That way, I can make it that much lighter and more delicate without worrying about the stone coming loose. This hardness would be lost if the piece needed to be soldered or welded but, because I spent many a night thinking about this rather than sleeping, that is not a concern.
Once it’s filed down to within an inch (25.4mm) of its life, and finished, the holes for the chain can be drilled and the diamond set.
The scrap left from the piercing can be reused, and a bit of new material added to make a new, larger Smartie. This is rolled out to something
in the neighbourhood of two millimeters and not annealed at all during the process. It’s important that the platinum be as hard as possible so that it can be pierced out to a vanishingly thin framework. Effect is everything.
The layout of the constellation is fairly straightforward, the holes drilled and opened up, and the piece pierced out. I’m not including photos of that process because it’s pretty much like the previous piece and, besides, I didn’t take any pictures of that part of the operation. I was busy. Leave me alone.
The framework is cleaned up with all the tools at our
disposal and left with sort of a long, triangular cross-section, (a knife-edge being the term), with just the finest of top surfaces. This, you see, is a very old construction technique that I stole. Once again, holes are drilled in the cunningly preserved attachment points so that no soldering or welding is necessary. All the surfaces of the frame are fine-filed, sanded, and burnished to a high polish at this point and then the whole shebang is mounted in a shellac-stick preparatory to setting and finishing.
The beaded texture is called Mille-graine, or milgrain if you’re a Yankee minimalist, and is a great technique for finishing off a piece where it is desirable to have the framework disappear as much as possible. This is why the sides of the frame, inside and out, were finished first. Done properly, the sides of the frame reflect the surface behind the piece and camouflage its very existence. These old dudes were full of tricks like this.
From here, it’s a simple matter to make up some small jump rings, solder them to the ends of a nice chain, and attach them to the pendant. My cavalier approach to this final, very important step is, once again, due to the fact that I was in a creative frenzy and stopped taking pictures. As usual, I tried to make the jump rings very small. So small, in fact, that they bind on the attachment points and don’t give the necessary freedom of movement that I so desired. It’s pretty good, though, so I didn’t have to re-do them.
Here’s the finished piece:
Or at least an unaccountably fuzzy picture of it. Must deal with that.