This is the first in a series of articles for those of you who want to know a bit more about basic metal work, sometimes called fabrication. This is not complicated, no lost wax casting, bezel setting or soldering, just simple metal fabrication; but you can do a lot with simple techniques.
Rembrandt employs over 100 employees in their factory in New York. Rembrandt is a fully integrated jewelry manufacturer with a complete tool and die facility with in house designing and model making on site. Here’s how it works when Rembrandt creates a new charm: It all starts with a model created by hand in the model area by skilled artisans. They are miniature works of art created out of metal, wood or other modeling materials, using items such as photo’s and sketches as a guide. The original sculpture is then used to make a rubber or metal master mold of the charm. This master mold is used to male quantities of “waxes”.
Assuming that all has gone well, once this step is completed the wax will have drained out and the remaining plaster is now the mold into which your metal of choice (silver, gold or platinum) will be cast. After the metal is cast, it is ready to be finished. This is a time-consuming process which requires the use of various tools like small files (much like nail files)and little polishing wheels. Then, any stones (diamonds, rubies, sapphires etc) are added. It is always wonderful to see the pleased look on client’s faces at the end of this journey.
The waxes are then soldered to a base which forms a wax tree. This wax tree is then inserted into a cylindrical flask called an investment flask. The cylindrical flask is filled with a very fine smooth plaster. This fills in all the spaces left around the waxes. The flask is then baked at a very high temperature, which causes the wax to vaporize. This is how “lost microfusione acciaio inox” got its name! The spaces that are left when the wax melts create numerous replicas of the original master mold. These spaces re then filled with melted pellets of gold or silver and allowed to harden. When the plaster is washed away, the raw charm castings are exposed. These castings then undergo hours of hand finishing and polishing, to create the finely detailed charms that make up the Rembrandt Charm Collection.
Early man was at the mercy of so many dangers. Naked, without fur or sharp teeth, he depended on his skill and ability to think to see him through the day. A harmless pebble blessed with the power to keep him safe must have been some, if not great comfort.
Sand casting aluminum is very common and is a popular way to break in a new furnace. Casters use sand mixed with a bonding agent to create a mold around the item to be cast. The item, or pattern, is removed very carefully revealing the mold. If there will be any empty spaces in the finished product then a core is added to the mold. The core can be made of sand and is placed so that the molten metal fills the area of the mold around it. So, say you’re making a picture frame you will place a cone where the glass will go so the molten aluminum will not fill that area.
The huge, rugged and headless ‘Yaksha’ of Handigaun is the earliest stone sculpture discovered in Nepal and dates back to the 1st century A.D. Some other early stone sculptures are ‘Sri Laxmi’and ‘Vishnu’ (both 2nd century A.D.), also unearthed in Handigaun.
Once the bronze has been poured and has cooled, the shell is then carefully chipped away, leaving a cast of the original sculpture in bronze. Any flaws are removed, the sculpture can be buffed and left its natural bronze color, or painted. This process is very labor intensive and expensive, but it results in such fine quality castings that it is still used after 4000 years.