The knob itself had a small shaft (about 1/8" diameter and 1" long) on its back side that fit into a slot inside the door and indirectly moved the dead bolt. The problem occurred when this shaft snapped free from the back of the knob. Of course, I still took apart the entire door lock mechanism just to see how it worked, even though it wasn't really necessary. I am a guy, after all.
I had initially intended to visit the local antique hardware store, Connor's Architectural Antiques, and try to find a replacement. Fortunately, before I got there, it occurred to me that I could probably just reattach the two pieces using a suitable metal epoxy. After consulting the web site ThisToThat.com, I decided to use JB Weld for the job. A visit to one of the steampunk DIY forums confirmed that this was a popular choice for brass. I've used JB Weld for emergency repairs on steel back in my Jeep days, and I had some on hand. For some reason, it never occurred to me to use it for brass.
|The lock mechanism. The broken knob|
turns the upper (dead bolt) mechanism.
The key to any secure bond is surface prep. I cleaned both surfaces as well as possible using sand paper, brake cleaner, and Q-tips. Once all the crud was gone, I scored the surface of the shaft with a utility knife so that the JB Weld would have something to grab onto during the rotational force of every day use. I then roughed up the remaining shaft surface with some 60-grit sandpaper, just for good measure.
|The knob's shaft fits into this slot|
While the epoxy was curing, I used a file to bevel the edges of the dead bolt and latch plate so that there wasn't so much resistance when the knob was turned and the parts contacted each other. All of these parts are brass, so working them with a file is really easy.
|The repaired knob & shaft|
Have you ever had to repair a piece of old hardware rather than replace it? I'd love to hear your story in the comments below.