Here are some very helpful stone setting tips provided by Gerald Lewy to help and guide you when working on gemstones.
When securing stones, please use a soft metal pusher. I suggest a copper or brass pusher. This will prevent making deep marks in the prongs, which can be difficult to remove later.
I use flat-edge and tapered-edge pumice wheels of #180 grit on all of my setting items. It’s not because of being rough on my work. It’s because it’s a mark of a ‘careful, high quality setter’. I remove all of the plier marks, graver slipping, andjust the general rough edges left by the ‘casing house’.
When bright-cutting the inside bezel for a ‘gypsy’ set stone, apply downward pressure with your finger to the #39 flat graver. This will give you a consistent applied control to the cutting tool and not leave a jagged edge when cutting.
When you are working with many diamonds it is advisable to pull out your lap tray under your bench peg. This will surely help you in retrieving dropped stones. I always lay a rubber pad in the tray, as this will prevent bouncing of the lightweight stones.
Use a smaller round bur at the under side of the holes to counter-sink them. This will remove any burs left from drilling and it will also give a brighter finish to the under side of the jewelry.
Always clean your gold shavings with a nylon brush after drilling. The reason is that when the shavings are left inside the hole and the diamond is placed into it and beads are raised, you might think that the diamond is secured. However, when the item is placed in the ultrasonic cleaner, the shavings are released and the diamond becomes loose!
If you are working on a plate for bead setting, you should take preventive measures for eye glare, by rubbing emery paper on the gold surface.
The correct depth of a diamond or stone for bead setting is to have the stone’s table located just at the surface of the metal. The difference in height of the table to the girdle is the correct depth for raising beads.
Before setting a diamond or other small stone down into the metal, open up the base of the hole with a small round bur. Some diamonds have a deeper pavilion, and will cause trouble for you while adjusting for the correct depth. Removing the ‘extra’metal will allow the stone to set down into the hole. A wider opening will also allow the polishing compounds to exit more easily while in the ultra-sonic cleaner.
Don’t limit yourself to one graver for bead-raising. I use 4 or 5 different ones at my setting bench. Some beads just need a heavier pushing action while others just need a little piece of metal to hold the stone. I prefer a simple Onglette #2 and shape it to my specifications. One is thin, some are thicker and some have a larger face.
When attempting to raise beads, visualize a square or ‘picture frame’ around each diamond. At the corners of the frame is exactly where the bead should be placed. A straight line should be formed from the outside of the bead, to the edge of the stone, to the outside of the next bead. Then the bright-cutting can be done without damage to the beads.
Just before you remove a diamond or any precious gemstone, observe any inclusions or defects in the stone. Always keep your 10X ‘Triplet Loupe’ at your side. Take note and record any inclusions or have the client view the inclusions themselves. I speak from experience. If you are in doubt about a stone DON’T SET IT. Being an over cautious setter is far more rewarding than paying for its replacement.