Hello friends! I am attempting to make a higher end copper ring by lining it with fine silver. I soldered the silver and copper together first, but then when I try to solder the seam it separates. Any ideas why? Thanks!
I've had this problem before, too! A friend told me it was because I had work hardened my piece so much that when I applied enough heat, it relaxed the metal and removed any tension I had been relying on to hold the seam together. In the end, I used a binding wire to keep everything snug while I soldered. I find binding wire to be rather cumbersome, but it worked!
I would say odds are you are not heating enough, and probably not sanding the seam as much as you should. Two different metals such as this will react differently to heat, so there is a slight movement as the metals expand under flame. I would start over, and make sure both pieces are properly annealed, and sanded, then use a mallet to make both pieces perfectly flat, then solder. After the metal is bonded, anneal it again before you bend it into shape. I would also use binding wire while soldering. Hope this helps.