QuestionI do stained glass soldering (not torch) on a variety of stones, etc and have been asked to do a large, loose faceted smoky topaz. I plan to foil a very thin strip around the edge of the stone, flux, and solder it, and do some simple silver wire work on parts of it, including a wire bale, thereby making it wearable as a pendant. The topaz is probably 8 carat size and is beautifully faceted. My question is: is it safe to do this little bit of soldering on a stone like this without damaging/cracking it? I have never had this happen before, but am only concerned because of the sentimental value of this stone to my customer and the size. Can it take the heat of soldering? I use a very light touch while soldering and it would be a very thin edge of solder only, but may require repeated applications as I do a type of "solder scupturing" whereby I apply several different layers and swirl/scupt it with the iron to create depth in the solder rather than a smooth, thin bead of solder. ** I am scheduled to do this piece tomorrow morning (Mon June 30) so would appreciate a reply ASAP! Thanks!
AnswerBarb, it is too bad you do not have a less valuable smoky quartz to use in a trial run. Even so, using the Tiffany method of copper foil then the solder connections and sculpting should be ok. The heat of a soldering iron directly on the stone is not recommended but working with the foil enough heat dissipates to make it safe. If the stone becomes heated to some extent, a uniform heat through out the stone is safer than heating one area too hot while the rest is cool. It might be better to work around the gem rather than to focus on one area at a time, depending of course on your technique with the iron.
Pay careful attention to this: Do not quench or cool the stone suddenly. Allow air cooling. Heat stress of non-uniform heat or sudden heat change will cause more problems than basic solder application to the foil will ever cause.
Before soldering, check the stone with a light going through the material to see if there are any cracks of breaks visible inside the stone. If so, you might want to be on the safe side and use the least heat possible around those areas. Generally, smoky quartz(misnomer is smoky topaz) is quite free of such flaws.
I seem to recall a much larger iron for doing lead came than for copper foil. Is this correct? The foil method seems ideal for what you want to create and I believe all should go just fine.
God Bless and Peace. Thomas June 29, 2008 2:26pm
