Precious metal clay is a wonderful material: it allows even an inexperienced jewelry maker to put together a jewelry piece without soldering. The easiest way is of course gluing together elements of unfired silver clay. But how do you assemble a piece containing both fired and unfired elements? Some tutorials tell you just to use water based silver clay paste or even your own paste made from recycled sawdust. That won’t hold if at least one of the elements is metal! The best way would be to fire the unfired element and then fix metal to metal using a magic glue: Art Clay Silver Oil Paste.
|Picture 1. Torch fired piece held together by Oil Paste
Art Clay Silver Oil Paste is a kind of solder, but an ingenious one. It doesn’t only fill cracks, it can fill gaps too. As we all (should) know, solder can never be used for gap filling. For successful soldering there must be NO GAPS between the adjoining surfaces. Another advantage of the Oil Paste is that it has exactly the same physical and chemical properties as the silver piece itself. It is in fact fine silver, with the same melting temperature, so it can be refired indefinitely with the rest of the piece. It is both solder and fine silver, combining the best of the two worlds.
Unfortunately there is a substantial disadvantage: the hold of the Oil Paste is never as strong as the hold of the solder. Therefore I would never use it for critical points like brooch pins. Pendants and earrings experience the least mechanical loads and their elements can be ‘glued together’ with this medium. But what if the unfired Oil Paste is too weak to hold them together in the unfired state and the pieces keep breaking off? It happened to me when making these fancy earrings. The windmill ‘blades’ kept breaking off even before I could safely bring the piece to the kiln. At last I lost my patience (which is not a good thing when making jewelry), grabbed the torch and ‘soldered’ the blades as good as it gets, just to get some hold.
|Picture 2. Cracks filled with Oil Paste again
Now the pieces did not break off anymore. Gaps became cracks. So I filled the cracks with the Oil Paste again, let them dry and fired them in the kiln for a smooth result. It is quite difficult to maintain the same temperature for the whole piece when firing with torch. Inevitably some areas will be ‘underfired’ or ‘overfired’, and some thinner elements, like bezel wire, even run the risk to be scorched. Kiln firing guarantees an even temperature distribution through the whole piece.
On the other hand, if a crack is discovered on a piece which has already been soldered, it is quite tricky to refire the piece in the kiln. The solder will melt down, etching holes in its place. The torch allows to point-“solder” the crack with the Oil Paste, without causing the other soldered points to melt down.
|Picture 3. The result
The result was quite satisfactory. There are no visible cracks on the earrings, and the bond is quite strong, at least for the earrings.
The conclusion: before making a bond bridge the gaps. It applies to many more things in life than making silver clay jewelry only.