Last issue we installed a new full prong on an opal and emerald pendant. This issue was supposed to be a continuation of the same project, i.e. retipping an emerald on the same piece. However, as the saying goes “the best laid plans of mice and men of go away.”
The piece shipped out before I could take photos of the tipping work. However since retipping prongs in close proximity to sensitive stones is a common task with laser welding, It happen to have another piece on hand that will do nicely.
This issue will address the topic of prong retipping. The method I use depends on the piece I’m working with. Our subject is an emerald and diamond ring that has some prongs on the diamonds that need retipping. Since removing this particular center emerald would be risky, the customer opted for laser welding instead.
After appraising the situation, I thought it best not to use wire to simply build up the prong on the crown side of the stone. There was a wafer thin piece of tip left and it would easily be blown away with the laser and would not be a good base for build up. Besides, it would actually take longer than the procedure I chose. I decided to cut the prong off at the girdle of the diamond at the same angle of the crown of side of the stone.
I make sure the angle and height that I cut off the old prong tip is such that when I place a wire or REDI-PRONG on the tip of the prong, there is no gap in the bearing between the girdle and prong or between the prong tip and the crown of the stone.
Using beeswax to hold a REDI- PRONG in place, and remembering that laser welds do not flow through the seam/joint, let the REDI-PRONG hang over the backside of the prong or let it come short of covering the top surface of the prong where it is cut off. Tack the tip in place and then you can “landslide” the excess metal over the backside/sides of the prong (in the case of the overhang) or you can add 30ga to fill in where it doesn’t cover the prong. In the case of the overhang, I shoot it a few times under the overhanging metal first, then landslide it from the top down, making sure to shoot at an angle away from the stone.
Reminder: Be aware of what you have in the background and always try to shoot at angles away from things you don’t want to hit; either directly or indirectly (by ricochet).
I try not to shoot at an angle perpendicular to the prong and tip/wire, except to tack the piece when first applying it. I get good results from shooting at better than 45 degrees or sharper and “away”, kind of like making glancing blows.
A note about REDI-PRONGS: I like REDI-PRONGS with and without solder because they are already a good shape, have very little clean up (which saves me time), sizes and shapes are varied (and uniform within each size), and the metal flows nicely. You can get them from your findings supplier or directly from REDI-PRONGS.
Now you can file and polish as you normally would. No worries about pitting because of over heating solder here! The weld is strong and the tip is substantial.
A word of caution: I don’t know what you’ve heard from your laser company or through another source about how “you can tip emeralds with a laser, etc.”
TAKE EVERY PRECAUTION POSSIBLE WHEN TIPPING ANY STONE. You can and WILL damage stones with a laser, even sometimes when you are trying to be careful! My rule of thumb…use the tipping technique that is the least likely to cause damage and personal stress. Sometimes it is still best to take out the stone and reset it.
The next issue will be the third in this series on tipping. Don’t miss it!