Bead and Bright Setting
The Four Bead Method
Tom Weishaar C.M.B.J.
1. In the last issue of Bench Magazine I demonstrated how I would go about carving the wax model for this unusual mother’s ring design.
2. The wax model has now been cast into platinum with a 10% iridium alloy. As you can see from the design the detail elements have not been added to the casting yet. The bezels for the side colored stones and the kite shapes between the shanks will be fabricated and added later. One good rule of thumb that I try to abide by is to always set my diamonds first and heat sensitive stones last. The advent of laser technology is diminishing the importance of this rule because repair work or fabricated elements can be added without damaging heat sensitive stones, even in platinum.
3. One of the tricks I like to use is to apply a coating of sticky wax to the metal surface. This trick allows me to stick the melee onto the ring so that I can make sure stones are right where I want them to be. You can see in the picture that by pulling the melee from the metal leaves a space in the wax. I then make the stones positions using a sharp tool and clean the remaining wax off with a steamer.
4. I like to use a spring loaded center punch, available at most automotive stores, to make an indentation in the metal. This small depression helps to keep my drill bits from wandering when I drill the pilot holes.
5. I feel that digital calipers are very important if you want to achieve high quality stones setting. I start a project by measuring each melee and recording its diameter. You’ll see why I think this is so important is next few pictures.
6. Another of my many rules pertains to drilling the pilot holes. I like to use a drill bit that is 50% of the diameter of the melee. I start with a small pilot hole and then work up to larger bits for larger holes. Doing this saves wear and tear on my burs, especially when I’m working with a gummy metal like platinum.
7. Next I need to “open” the pilot hole. For this task I use an “aggressive bur” such as a ball or bud bur. These burs have widely spaced cutting flutes and spiraling rake angles that allow the bur to dig quickly into the metal without overheating. These burs act very similarly to the way a drill bit cuts. To open the hole I use a bur that is 90% of the diameter of the stone.
8. The size of the setting bur you use is very important. Always choose a bur that is slightly smaller than the melee you are setting. This bur is .09 mm smaller than my first stone. It’s much better to wiggle a bur as it cuts to get the correct seat diameter than it is to over-cut the seat with a bur that is too large. The most frequent error made by inexperienced stone setters is to over-cut the seat. Inexpensive slide calipers are not accurate enough to use in quality stone setting work and the $50.00 that a good digital caliper costs will more than pay for itself in saved time.
9. This picture shows a vanadium steel setting bur. The bur has tightly spaced cutting flutes and no rake angle (no spiral). This bur is not aggressive but it will cut a very clean seat. The bur will also overheat and dull quickly if operated at high speeds. If you choose vanadium burs just be sure to clean them frequently, keep them lubricated and run them at slow RPMs. Please notice that I like to leave about ½ mm of space between the edge of the seat and the side of the ring.
Now another rule: Melee less than 3mm in diameter are seated to a depth so that the table facet is flush with the surface of the metal. Stones over 3mm are seated less deep so the table facet will be slightly above the metal surface.
10. After all the seats have been cut and checked using the actual stone it’s time to cut the “frame lines”. Frame lines do just what their name implies; they frame in the area that you will be setting stones in. I use either a small onglette (4/0) or a knife (K-0) graver to cut the frame lines. This graver needs to be very sharp but not necessarily polished. I’d like to add that I recently fell in love with the GRS brand of high speed tool steel gravers; they are the best I’ve tried so far.
You can see in the picture that the frame line cuts into the seat. The frame line is beveled out toward the edge of the ring and it goes down to the same depth as the seat.
11. This close-up picture shows what your seats should look like after the frame lines have been cut. Please notice that the shape between each seat looks like a tiny hour-glass.
12. In this picture I am using my onglette graver to “isolate” the beads. Each of the small hour-glass shapes is to be divided into four triangular beads and a center kite shaped element. To do this you begin the cut in the middle, outer edge of the hourglass and cut diagonally in toward the seat. It’s fine to make several shallow passes in order to get the cut to the proper depth. As you cut you should angle the graver in toward the center kite shape so as to preserve as much metal in the bead as is possible.