The best method to retip a stone with a point is to make a cap in the shape of the prong. Then with a minimum of solder, attach the cap to the top of the prong. Do Not allow solder to flow under the stone, completely encircling the stone point. If the prong is worn to the place that it needs more work than just a cap, it is best to remove the stone and replace the crown or prong.
When re-tipping worn prongs on a cluster of stones that will not withstand the heat of your torch, such as emeralds or jade, first remove all the stones. Then select a piece of gold tubing to just fit over the prong. Cut pieces of tubing the length of the prong, and place over each prong (you may need to file some of the prongs to fit the tubing). Solder in place with medium solder. With a little shaping and polishing, you have new prongs ready to re-set the stones. Using this method each prong is easily placed in the correct position, and they will not shift while soldering the other prongs.
When sizing, make the ring 1/8 size too small. Clean the solder joint on the inside of the ring only. Next, place the ring on a ring mandrel and hammer across the solder joint until the ring reaches the correct size. Finally, clean up the outside of the ring with a file, emery, and polish the ring. This will help you to be more accurate in your sizing (if you are a little too large you will need to resize). In addition, this will work-harden the sizing area making a stronger joint, and finishing and polishing will be easier.
Sizing heavy gent’s rings can be difficult because of the metal thickness in the shank. Straightening the ring on a ring mandrel can be particularly challenging. Using a Lead-filled weighted rawhide mallet, or a dead-blow mallet will provide the extra force needed to make this job easier.
In addition, when opening-up a shank for up sizing, one of these mallets can be used to force the ring down on a ring mandrel, after sawing through the shank.
When a customer brings in a coin pendant with the screw striped, I clean the threads from the pendant with a Krause bur then fit a wire in the hole and rivet it closed.
Do Not solder the wire in, actually rivet the ends down. The tubes are soldered to the frame and will move or come off easily if you try to solder the wire in. Also if the customer ever wants to change the coin you can cut the rivet head off and replace the rivet.
To keep a coin from turning in a coin frame with tabs, take a piece of wire and roll it through a rolling mill. Then cut pieces to wedge between the coin and frame under each tab. The length and thickness of the piece depends on how loose the coin is, but at least three times the width of the tab. Then push the tab over with a prong pusher. A brass pusher works well, but if you’re concerned with slipping off and marring the coin a wooden dowel rod in a graver handle would work or make a pusher from a plastic handle from a tooth brush.
Take a warm ball of Jett Sett (the plastic substitute for shellac) and place in a 2” X 3” plastic bag. Spread it out to fill the bag approximately one sixteenth inch thick, then fold the bag in half to 2” X 1 1/2 “. When hardened trim off the top of the bag. Then, when you have a ring shank or other jewelry that is too thin to hold tightly, place the jewelry between the two halves of the bag and insert in your ring clamp.
When rounding out the rings from sizing use a double face mallet, brass on one side nylon on the other. Use the nylon side to straighten out the ring shank. Like a rawhide mallet it will bend the shank but not stretch it. Then if the ring is a little too small (quarter size or less) turn the hammer around in your hand and tap across the seam with the brass side. This saves time from putting down the rawhide mallet and picking up a steel hammer then going back to the rawhide mallet.
To measure the size of a finger with a large knuckle, take an inexpensive set of plastic ring sizers and cut a slit in them with a fine saw blade. Then when measuring with them, they will open to go over the knuckle and you can measure the finger for a proper fit of an adjustable shank.