I've been thinking about restoring the door latches on my Isetta's for awhile. The original color of Isetta door latches is silver/grey paint that matches the parking brake. I'm sure because the original silver paint had worn off, my door latches had been painted over several times with black enamel paint by the previous owner. I decided that to restore the latch properly, I really needed to take it apart. While the Isetta purist may cringe, I also decided that since the parking brake and door latch are parts that are handled frequently causing the paint to get scatched up and wear off, that I was going to nickel plate both of them for the sake of durability. Little did I know what a can of worms this seemingly small project would turn into. The latch is held together with five rivets, and this is where the fun started. My original idea was that I was going to drill out the rivet from the back side, and tap it out with a punch. WRONG! Little did I know that these rivets are actually a special shouldered rivet that is larger diameter on the inside than the part that goes through the cover. To disassemble an Isetta door latch, you need to drill out the rivet from both sides. After disassembling a door latch, I think the best approach is to drill out the front side first. I would start by using a center punch in the center of the rivet, and start with a small 1/16" bit and drilling progressively larger holes until you can remove the exposed smashed part of the rivet with pliers. I didn't want to grind of the head of rivets because I didn't want to put any grind/scratch marks on the cover of the latch. Once the heads of the rivets have been drilled out, the cover can be gently pried off revealing the internal components.
A front and backside photo of the door latch before disassembly.
A photo of the internal components of the door latch, and a photo of the components removed with what's left of the original rivets.
Obviously the original rivets were destroyed in the process of disassembling the latch. Fortunately I recently got a new toy that allowed me to fabricate a new set.
One small design change I made was rather than these being rivets with smashed heads, I drilled and tapped mine so that I could use small machine screws for the reassembly.
One other problem I found was the mechanism that moves the latch opened and closed had a significant amount of wear. I built up the area of wear with a small weld bead, and reshaped the piece to it's original shape.
A photo of the door latch cover bead blasted and then nickel plated.
The first photo shows the back plate of the door latch after bead blasting and nickel plating with the new rivet replacements attached. The second photo shows the restored internal components installed.
A couple of photos of the finished door latch.