A bargain lamp find in a big store was discovered to have a broken ring on the top. The ring appeared to be made out of brass or possibly plated steel. We decided to buy it anyway and fix it by silver soldering (brazing).
The ends were filed to clean them up. I mixed up some flux and applied it to the two ends. Because it was a relatively thin ring I used some large clamps to act as heat shunts.
The ends were heated with a little butane/propane torch until they were red, I them pushed them together and applied the solder. It was then just a case of waiting till it cooled down and cleaning up with some wire wool.