By Chris Wantuck
Much of the time we work on individual parts of our restoration projects, but there comes a time when several of these parts can come together as subassemblies. In this article we want to show how several topics that we have previously covered can go a long way to making your restoration project more manageable as well as more enjoyable. For those previous articles, see Organization, The Threaded Rivet, Rotary Tools, and Electrical Connections .
Let's look at the reassembly of cowl lights used on our Lincoln Sedan restoration project. They were earlier disassembled and sent to the chrome plater. In order to maintain quality around mating pieces, the lights had to be disassembled before plating. It is paying attention to details like this that makes all the difference in the overall quality of our final restoration.
Disassembly involved using small rotary tools, namely the mini cut off wheels and carbide tools. Three small rivets were ground down from the inside where any scratches that might occur during the grinding process wouldn't be seen. The inside brass sheet retainer is gently pried off and the cowl's back shell and separated from the mounting bracket. Photo 1 (photos start on page 2) shows the cowl lamp parts as they came back from the plater. This is where our organization comes into play. By placing parts in separate envelopes, it will be easier and more logical when we need the various pieces required for reassembly (Photo 2).
We now refer to our discussion of using Threaded Rivets. Threaded Rivets come in many sizes. The hole size in this case is clearly a #6 and two head styles are available, the Truss Head and the Round Head. The Truss Head fits over the hole, but the Round Head fits down in the bracket's recessed hole and more resembles the original rivet (Photos 3 & 4). Before attempting reassembly, test fit all components. Sometimes the plating process can change hole sizes just enough to be problematic. A light coating of clear adhesive/sealant is applied to the bracket's mating surface before reassembly of the shell (Photo 5). Photo 6 shows the cowl lamp thus far.
A step that was performed several years ago was to have the cowl lamp reflectors recoated using the UVIRA process. Reflectors are first nickel plated and sent to the UVIRA Company and a specialized coating is applied. This is the same coating used in medical operating room lighting systems. It yields higher reflectivity than resilvering (see Photo 7).
As we learned in our Electrical Connections article, good connections are the result of both mechanical (crimp) and soldered junctions. We wanted to improve the grounding of the bayonet socket to the bracket and the shell. As desgned, the socket relied on a mechanical friction fit into the reflector to provide its ground connection. It may be adequate, but it does rely on the reflector making good contact to the front bezel and spring retainer. Over time, oxidation and dirt can (and usually does) cause a less than desirable ground. One better method for a good ground connection is to install a separate ground wire to the base. Photo 8 shows the separate ground wire soldered to the back of the socket.