Solder in right places should fix lamp
Q I have a large, very heavy Tiffany-style hanging lamp that belonged to my great-grandfather. It is more than 100 years old. About 10 years ago, it was severely damaged in shipping. A stained-glass store spent several months repairing and piecing it together. We hung it in our kitchen six years ago. Recently, when we were replacing the light bulb, we noticed that some of the welding on the crown attachment had broken off. Where can I find someone who can weld the crown back on and add more support if needed for this fragile antique lamp?
A It’s unlikely that the crown on your lamp was welded. Almost certainly, solder is what’s holding it together. Both are ways of connecting metal pieces, but they are very different. Welding is done at extremely high heat, enough to cause the metal in the parts to flow together; the result, if it’s done right, is a joint that is as strong as if it were one piece. Soldering is a lower-temperature process in which a filler metal (traditionally a mixture of lead and tin) is melted enough to bond with the metal parts being joined. When the solder cools, it is the bridge between the parts. Solder joints aren’t as strong as welded ones.
Tiffany-style lamps are made by crimping narrow pieces of copper foil around the edges of the glass pieces, then soldering over the copper on adjoining pieces so the bead of copper holds them together.
Although lead-free solder exists, the solder used for Tiffany-style stained glass is, even today, a mixture of tin and lead. If you are old enough to have played with the lead pipe in early versions of the board game Clue, you know that lead bends, which can result in the issue you’ve spotted.
“The problem is caused by the weight of the glass lamp and the small area, either a cap or a crown-like metal piece, that is responsible for carrying the weight,” said Pamela Joyce Wright, owner of Mclean Stained Glass Studio in Virginia. “Over time, the weight of the glass body pulls away from the cap.”
To repair your lamp, she would melt away the solder along the crown so she could push the pieces back into alignment. She would probably need to replace the copper foil along the glass there so that new solder would hold the pieces together.
To prevent the pieces from pulling apart again, she would add reinforcing: 24-gauge metal wire on the underside of the lamp. Then she would solder that to the lamp’s solder lines, running
it about a fourth of the way down and up into the cap.
“This acts on the same principle of buttresses of the old gothic cathedrals, where the weight is balanced and the piece becomes more structurally sound,” she wrote in an email.
In the pictures you sent,
Wright also spotted what appear to be missing pieces of the dotted “necklace” at the base of the ring. To fill in the missing pieces, she would shape beads of solder.
She estimated the repair would take a couple of days and would cost about US$250.
For The Washington Post