Help-Antique Ring Repair

Q: I have to solder a 1/4" spacer into the band of a large silver & gold antique ring. The ring has gold nuggets in a clear domed epoxy head. I can not remove the head like I would a stone. The band is silver with some gold inlay work on the sides. How can I keep the head cool enough to prevent damage while soldering in the spacer?

A:The easy way to do it is with a pair of heat sinks on either side of the filler. Aluminum is good, copper is better. Clamp the metal to the ring, use a hot very small flame, very little solder laid on the joint, and take the heat away as soon as the solder melts. With practice you will be able to it without the heatsinks. The secret is to be quick. Dont heat the ring and then try to stick the solder on it. Cut the solder first and lay a small piece on the joint and heat the joint from the back side. When the solder melts, quit. If it is really impossible to remove the epoxy, then the following should work. Place the epoxy and a large part of the ring in some wet sand (not just damp) - the sand holds the ring and the water keeps the epoxy cool. I've heard that some jewellers use a raw potato, but wet sand has always worked for me. Get as much of the ring as possible under the sand. Flux the joint, place a small snippet

of solder on it, then using a smallish, very hot, flame (oxy-propane or oxy -hydrogen is fine), play the heat on until the flux stops bubbling then really zap the flame on to melt the solder as quickly as possible. Remove the flame as soon as the solder melts, and allow to cool down in the wet sand. The water will boil a bit, but if the flame is hot and big enough it will work OK - I've even done it with shell cameos, but I wouldn't recommend it unless there is really no alternative. The trick really amounts to getting the joint hot enough before the heat travels to the epoxy. If you've never tried this technique before, practise on some scrap silver first.