Here's how the lamp came to me. The four pieces at the top had loosened from the sides. One piece had detached, as did the round metal center.
Here's another "before the repair" view ..
For any lamp repair, its necessary to remove all the loose or broken pieces and clean them thoroughly. Here I've already sprayed the edges with a household cleaner to remove the old copper foil adhesive. Now I'm using an old plastic ruler to scrape off any remaining adhesive. Notice that before I removed each piece of glass, I numbered it as well as numbering the side of the lamp where each piece will go.
After the pieces are cleared of debris, I tugged off the old copper foil and solder from the upper border. Some of it came off easily, some needed to be melted off with a soldering iron. When I'm melting solder, I always wear a lead-protectant mask and have a filtered fan running, for safety. To assure that the copper foil adheres well, it's also necessary to grind the edges of the glass. With this lamp, as with many others, the glass has not been ground. So I used a metal file to do the job. The edge gets a thorough cleaning afterwards.
Next, I apply new 7/32" adhesive copper foil to the borders of each piece. Here I'm using a "fid" or flexible plastic wand to burnish the foil onto the glass, which I've placed on the center of the side and wrapped around evenly to each side.
The outer rim of the lamp has new copper foil, as does each piece of glass. I've measured the interior of the rectangle and placed the glass down to assure that it is the correct size. Then I've taped it in place as shown.
I'm now reaching inside the rectangle to coat the copper foil with the green solution which is liquid flux. Flux is a chemical which acts as a catalyst to promote the melting of the solder. Once the foil has been fluxed, I apply solder to lock the glass in place.Then the soldered area gets another thorough cleaning.
After the interior is secure, I solder the top of the lamp as shown.
Next comes the metal cap. I've melted off the old solder and foil from this as well, and I've applied new copper foil. Then I solder it over the open square, from both sides, making sure that it is solidly attached.
Now the metal cap is in place. I thoroughly clean off all the flux to prepare for the application of the patina.
Next, I apply Novacan Black Patina to the solder. It reacts instantly, turning it black. Another cleaning follows.
And once more, here's the repaired lamp. The wiring and bulb are separate, of course, and the owner, Prit, will have reassembled the lamp upon its return. Thank you Prit, for the chance to repair your artful lamp .. It was a pleasure!