I realized after I posted the last blog that some folks might not have a clue about the process of riveting. Riveting was one of the most common methods for joining base metals together prior to the advent of modern soldering techniques and fancy gas torches. If you are interested in reading about modern soldering techniques. I wrote a blog on the technique a while ago.
But back to riveting. I made a quick, and not particularly artistic, picture of the basic riveting process. How is that for a fancy hammer?! But hopefully this gives you the basic idea. The metal of the rivet, or the end of the purse frame bar or pivot is simply moved by hammering.
But back to my process! I also spent a ton of time looking at examples in museums. I found several at the Museum of London that had a similarly shaped purse bar and pivot. This purse frame was photographed upside down, but you can see that it is very similar. And this purse frame is not only similar, but also has a surviving purse frame ring. Excellent! Now I even have a potential model for the ring on my purse frame!
Next it was time to actually make a mold of the frame that I have. I used modern materials to make my molds. Because the actual artifact is metal I was able to use silicone mold sheets to make the initial mold. This material requires heating, in a special press known as a Vulcanizer, to create a rubber-like mold. Once this mold was created I was able to remove the original artifact and inject molten casting wax into the cavity of the mold. This wax creates an exact replica of the original artifact. I made several copies of the original purse frame in wax, and then began cutting the wax apart into the individual pieces that make up the purse. At this point it was possible for me to repair any flaws in the original purse frame pieces, like corrosion or other pitting. Once the individual pieces of the purse looked the way I wanted them to, I was able to use another modern silicone mold material, called Room Temperature Vulcanizing Silicone (RTV), that allowed me to easily create a mold of the individual wax replicas of the purse pieces.
Here is a picture of the original artifact and half of the Silicone mold that I made from it. At the bottom of the picture are the three RTV molds that were made of the individual repaired waxes. The new waxes that can be cast from these molds are the red objects above the RTV molds. You can see that I extended the worn and peaned ends of the original purse bar so that they would be long enough to hold new purse bar rings and still have room to be peaned over. I also extended the central pin on the pivot of the purse so that it will be long enough to go through the purse bar, put on the washer (shown on the right) and still have room to be peaned over.
Next Time: Time For Metal!