Thousands of years have past since the first goldsmiths hammered out the first adornments. We are now using Cad Cam to produce models, induction casting machines and a multitude of high tech gadgets to produce jewelry less expensive and faster than ever before. In spite of all the technology we have today, it is my opinion that the finest jewelry ever made has been hand fabricated. Here is my reasoning, fabricated metal work hardens and is not only harder than cast metal but it keeps it shape during polishing much better than a piece that has been cast. I have worked on many nice pieces of cast jewelry that had a beautiful surface finish and then polished through that nice clean surface to a subsurface that has porosity or pits. I have not seen that with fabricated pieces. So why is there not more fabricated jewelry on the market? The time spent to produce a complicated fabricated piece is not close to being profitable as compared to mass produced lost wax cast jewelry.
I use Cad Cam to produce many of my designs. However, I have years of fabricating experience and I just enjoy fabricating fine jewelry and fabricating a master model for production. In 1998 I became the first bench jeweler in Wisconsin to receive the J. A. Certified Master Bench Jeweler title. The practical portion of the test consisted of three fabricating tests. One test was fabricating an 18k gold emerald cut pendant with filigree scroll work from supplied 18k gold flat stock and specifications. The second project was fabricating a platinum engagement ring with a round center stone and 2 baguettes from supplied platinum flat stock and specifications. The third portion of the test was to fabricate a sterling silver pill box with a 14k cross on a domed lid with bead set C Z’s set in the 14k cross from flat stock and sheet metal as per specifications. I took one week vacation and then took the bench test and completed the three fabricating jobs in the 36 hour deadline - 12 hours for each test. You are able to break up the test into whatever your schedule will allow, but I wanted to get it finished in as short a time frame as possible. I received a letter from Jewelers of America after completing the test stating
“All three graders liked the quality of craftsmanship on your Master Pieces and JA would love to use your bench tests as samples.” It didn’t take long for my answer.
I have 2 photos showing a sample of my fabrication work. The 18k mabe’ pearl pendant and earring set was fabricated from 18k sheet and flat sizing stock. The hand engraved garnet and diamond ring was fabricated in 18k and platinum,.Photos 1 and 1B. The tools I use for basic fabricating are the basic tools you would find in a jewelers repair bench, saw, files, hammers, gravers, mandrel, pliers, etc. In this article Jewelry Fabrication Part 1 we will start out with a basic oval bezel that will be a component in a pendant.
I am starting with 18k gold 4x4m square stock. Photo 2. The piece is first annealed.
Coat the 18k stock in boric acid solution and place it on a charcoal block and heat it with a torch until it is a dull red and let it air cool. Pickle the piece to remove all the boric acid from the stock. Failure to remove all boric acid residue will cause a rough finish on the surface of the gold when you run the stock through the rolling mill. For this particular piece I rolled it down in the rolling mill from 4x4m to .6mm x 5mm
Photo3. Be sure to anneal the gold when it starts to work harden, this will prevent the metal from buckling and deforming during the rolling process.
I then bent the rolled metal into the shape of the stone I am building the bezel for with a round nose plier and an anvil.
Photos 4 & 5. I like the metal ends of the bezel material to butt up to each other, then place the stone in the bezel to check the size and fit. I like the stone to fit smoothly in the bezel so I start slightly larger than I need to and carefully trim the seam until I obtain the correct fit. Since I am working with 18k yellow gold I soldered the seam with 18k hard solder.
Photo 6. I use hard solder to assemble a bezel like this to prevent the bezel from falling apart during the pendant construction when other components will be soldered to this part. Another bezel is constructed in exactly the same manner only this one is to slide into the first or outer part of the bezel. This will be the seat for the stone to sit upon. Before soldering the two parts together, I sand the inside of the outer bezel part and the outside of the inner bezel part to make a nice fit and helps the solder to flow more easily. Anneal both the inner and outer bezel pieces to relieve any tension in the parts to prevent the seams from opening during the soldering process. When annealing a soldered piece like this I start annealing as far from the seam as possible to relieve the tension in the part before the solder seam gets close to the flow temperature. Slide the inner bezel to the correct depth so the outer bezel is the right height to push over the stone to be set. Make a couple solder spots 90 degrees from the two bezel seams on both sides to keep the solder from flowing at the seams at the same time. When you do this the two parts are held together and the seams rarely come apart during the sweat soldering operation.
Photo 7. File the excess material from the back side of the bezel for a flat back. Check the fit of the stone.
Photo 8. The finished bezel.
Photo 9. Next month we will finish this amethyst and montana moss agate pendant.
In my article, Jewelry Fabrication Part 1, I demonstrated the process of building a Cabochon bezel from flat stock. You may have noticed in Part 1 of this article, photo 8 showed the finished cabochon bezel along with a bezel for a tongue shaped montana moss agate. That bezel for the tongue shaped stone was fabricated very much like the oval bezel. The difference is the bezel for the tongue shaped stone does not have an inner bezel part or seat, it is an oval bezel formed to the shape of the tongue shaped stone, but I capped one end. The stone is then pushed into that bezel until the stone seats against the end cap of the bezel. I will not show the process of building that bezel at the risk of being redundant.
In Jewelry Fabrication Part 2, I will make two round rods that will tie the three bezel parts together. The rods will be made of platinum ruthenium. They will run in a vertical direction from the tongue shaped stone bezel to the oval bezel with a small round bezel soldered to one of the vertical rods.
Photo 1 shows the basic layout of this pendant without the rods added. One way to do a job like this is to buy new platinum round wire, but I have sprues that have been removed from platinum castings that are already paid for. At $1,200 platinum prices it is too expensive to send that new platinum to the refiner. I often use the small sprues that are too small for any other practical use and melt them on a platinum soldering block into a small ball or a small bar. Always wear shaded eye protection when soldering or melting platinum. I then run the sprue thru my grooved rolling mill and use it for sizing stock or round wire for prong work or fabrication. Always keep the different alloyed platinum scrap separated and labeled if you are going to use it at the bench as described. Different alloys have different working characteristics. Platinum iridium and platinum ruthenium are the alloys I like to use in fabrication. Platinum cobalt is an alloy that casts well but the malleability is poor.
I will use the sprue in Photo 2 to form the two rods used in the design of this pendant. With the platinum ruthenium sprue, I start at the largest groove of my rolling mill and roll the metal through until the piece I started with starts to take the shape of the square groove of the mill (Photo 3).
If while rolling the stock thru the mill the square stock starts to twist or bend, the metal should be annealed (Photo 4).
Heat the metal to an orange color and hold it there for two to three minutes to change the grain structure of the metal. After the metal cools, I roll the stock through each consecutively smaller groove until I reach the desired dimensions (Photo 5).
Always use a platinum soldering block or pad to anneal, melt or solder platinum. The use of a charcoal or graphite block, or the use of acetylene as a fuel to heat your platinum should always be avoided. Platinum will absorb carbon as it is heated. Carbon, which is found in the above materials will cause the platinum to become brittle. I prefer propane or natural gas for platinum and palladium work. These are clean fuels and work very well with these metals.
Now to turn the square stock into round rod or wire I take the platinum back to the rolling mill to prepare it for the draw plate. Find the groove your square stock will fit into then move it to the next smaller groove. Roll about one fourth of an inch of one end of your stock into and back out of the rolling mill. This starts the taper. Move to the next smallest groove and roll your stock in just short of the first step of the taper. Proceed through the rest of the grooves until you have a nice taper on one end of your stock (Photo 6).
You may prefer to file a point on one end instead of rolling it, but with the price of platinum I would rather keep the weight in my stock and not in my bench pan.
With the square stock rolled to a nice taper I go to the draw plate, I find the smallest hole that the stock will fit thru then move to the next smallest hole and push the point of the stock into the hole and draw it through each consecutively smaller hole until I reach the desired size (Photo7).
After drawing wire through a draw plate by hand it usually has a slight curve. To true up and straighten the rod, I tighten the rod in my flex shaft hand piece. I use my flex shaft as a turning lathe. I place the round stock on a flat steel block and place a wood block (or end of a hammer handle) over the turning round stock to straighten the wire (Photo 8).
After this process, I turn the rod against a sanding stick until I achieve a fine polish (Photo 9).
Now I have a nice straight round pillar that I am able to use in the pendant from a scrap sprue. The process took about 10 minutes from start to finish and the only real difficulty is pulling the wire through my old plate. I have used highly polished carbide draw plates to make the job easier. If only I could remember where I put it!
Now I need to cut two pieces of stock to the same length. For this I use my handy dandy wire cutting jig. This little tool is a real time saver for fabricating. Adjust the stop, which is the black square metal piece on the end closet to the number 10 in Photo10.
Lay your stock in the bed of the tool, place the thumb lever over the stock and put pressure on the lever to securely hold the stock in place, then run your saw blade into the saw groove and cut the stock. After the cut piece of stock falls from the jig, slide the remaining stock up to the stop and cut another piece. With two pieces of stock cut to the same length I will true up the ends for the assembly process.
To square up the ends I use my tube holder (Photo 11) with the end close to the face of the tube holder and file the stock flush. The tube holder is made of mild steel so you need to take care not to file the end of the tube holder or the end will no longer be square. A better tool to use is a miter jig (Photo 11a).
This little Jig is harder than your file and will hold stock at 90 and 45 degrees for beautifully true angles and I don’t think they wear out ---- well as long as you only use a steel file and not a bench grinder!
This month I will show an old fixturing trick for assembling parts. When I say “old” I mean without the use of Tack, Pulse Arc, or Laser Welders. I learned this trick from my Dad years ago when I was having trouble assembling a number of crowns on a ladies freeform ring.
Photo 1 shows the parts that are to be assembled. The bezels and the pillars are polished and the pillars are cut to the correct length with the exact angles filed on the ends that will butt up to the oval bezel. You may butt the pillars up to the bezels and solder in the traditional manner by laying a chip of solder on the joint and heating until the solder flows. I have found that there is a little more clean up with this method and if I apply too much solder I end up with a fillet of solder at the joint. To achieve a very clean and almost invisible solder seam I spend a little extra time in preparation before soldering. For this project I use a tube holder to hold the pillar and with a ball bur I cut an indentation in the ends of the pillars ( Photo 2 ) .
I then flow solder into the indent on each end ( Photo 3 ) and file and sand the solder flush with the end of the pillar. The parts must have an exact fit for this method of soldering to work correctly. I like this method of soldering. When the solder flows there is just the right amount of solder for the joint and no chance of a fillet of solder at the base of the pillar, but a nice clean smooth joint. This does take a little longer to prepare but I think the results are worth the added effort.
Using modeling clay, form a flat slab on your bench. Modeling clay can be purchased at any Arts and Crafts store or department store. It is an oily clay that does not harden. I use modeling clay at the bench often for holding parts, investing, and hand engraving. It comes in a rectangular shape wrapped in plastic and almost looks like a colored stick of butter (Photo 4).
With the modeling clay formed into a flat slab on your bench use a square to scribe guide lines into the clay as a reference for the parts layout ( Photo 5 ).
Lay the parts on the flattened clay arranged in the order for soldering. When you are satisfied with the position of the parts, push the parts into the clay so half of the part is in the clay and the other half of the part protrudes from the clay ( Photo 6).
Mix a small amount of casting investment and pour it into a small container ( Photo 7 ) and lay the clay and the jewelry components on top of the investment container, making sure the parts are fully submerged in the investment ( Photo 8 ).
It is a good idea to paint the jewelry parts with investment prior to laying the parts in the investment to prevent air pockets or large bubbles under the parts. When the investment hardens fully , about 20 -30 minutes, peel the clay away from the investment and parts. The parts are now held in place by the investment.
Photo 9 shows the parts embedded in the investment exposing the back side of the pendant. Lightly steam the parts to remove residual oil and clay particles for a clean soldering surface.
Using a small paint brush paint a good coat of boric acid solution on the parts that are exposed. Add flux to the solder joints, solder as you normally would , or if you prepared the pillars as described earlier in this article just heat the joint area until the solder flows all around the perimeter of the pillar. Solder all the joints that need soldering and don’t forget the small diamond bezel that needs to be soldered to one of the pillars.
When the soldering is complete, pry the component from the investment ( Photo 10 ).
Pickle and steam the part clean. If you were careful with the solder and didn’t over heat the parts a light buff should finish off the piece nicely. Photo 11 is the finished piece after stone setting. The next step is to sell it!