From: Luke Chennell
I don’t know much about Solar or Grey and Davis lamps, so I can’t be of much help with these types of lamps, but I think I might be able to help readers generally with restoring brass lamps at home.
I tried taking on just that sort of project with a few lamps that were laying around the shop. I started out with virtually no knowledge of what I was doing, and have since learned a large amount. I can’t vouch for how all lamps are put together without looking, but starting from the top:
Most lamps have a three-tier chimney.
The top tier of the chimney was usually made by taking a flat piece of steel, soldering it to bent-over tabs that protrude from the first tier of the chimney, and then crimping the top piece to the flat round piece of steel.
To remove, there are two options: you can heat up where you see the tabs and gently pry each one loose (this option runs the risk of breaking the tabs off), or you can try to uncrimp the top piece from the steel plate (this runs the risk of cracking or denting the top).
The second tier of the chimney can be held on in any number of ways; usually it’s simply soldered to the protruding tabs coming up from the first tier. Sometimes it can be held by rivets. Rivets can be Dremel tooled off and later replaced with screws that are silver soldered to ensure they won’t vibrate loose. Or, if you’re a glutton for punishment, you can carefully re-rivet everything using brass wire as your raw rivet round stock.
The first tier of the chimney (usually a two-piece crimped affair) is generally held on by a crimp/solder fit into the main body of the tail light. To remove, gently pry the crimp loose and desolder. Be careful not to crack the brass, as it is extremely work hardened at any crimp point.
The main body is usually made up of four components: a door, the lenses and bezels, the reflector, and the body itself. Speaking in general terms, you will have to remove the bezels and glass before you can do much else with the lamp. Usually the reflector is soldered in-between the bezels and the main body; this can be one of the most tedious jobs of lamp restoration.
This is my method of dealing with glass and bezels. I heat the joint VERY carefully with the very end of the envelope of an acetylene-oxygen flame. I use acetylene and oxygen for this because of the flame’s very precise characteristics; the heat doesn’t tend to “bleed” away from its source as a propane flame does. You might find a propane flame works better. Anyway, I desolder the frames with the glass in them. I’ve found that bending the bezel edges to get the glass out mostly destroys the bezels. With careful heating, you won’t crack the glass, and will wind up with a separate bezel and glass assembly that’s a lot easier to put on by resoldering than by rehammering bezels onto glass.
With the glass and bezels off the lamp, you can generally also desolder the door (usually held in by a piece of brass formed around the wire and soldered into the main body on an extending tab), and then remove the reflector from the lamp. Be careful after you’ve desoldered both the glass and the door, as the main body has lost its major support (it may have supporting wires or strips running on the corner of the bezels) and will be susceptible to bending or twisting. Handle it carefully (a good piece of advice during all phases of brass lamp restoration).
Reflectors were done one of two ways: they were either silvered or were made of aluminum and polished. I don’t have the space (this is getting to be a long treatise) to talk about buffing and polishing, but I’ll be glad to go into those subjects if you so desire. If your aluminum reflectors are tarnished, buff them. If your silvered reflectors are bad, send them out to be resilvered.
With the reflectors out, you will be able to remove the first tier of the chimney of the lamp, and will also generally be able to remove the piece that holds the font (the part that holds the kerosene) from the lamp. Usually, these are crimped and soldered just like the first tier of the chimney was. The same cautions about work hardening apply.
With the lamp disassembled (sometimes half the battle is simply figuring out how things come apart), you’re ready to begin straightening. Brass is very easy to work and is susceptible to all known metal forming techniques, most of which are well described in any good sheet metal textbook.
However, brass does work harden much more readily than low carbon steel, and it doesn’t anneal as aluminum does (one of the primary mistakes I’ve seen brass lamp restorers use is to try to use the same techniques for annealing brass as they do aluminum. It doesn’t work, IMHO.) The recrystallization temperature of brass is well above 600 degrees, whereas aluminum is only 175 degrees. To anneal brass, you must heat the metal above this temperature. Once you have accomplished this temperature throughout the piece evenly (which can be very hard to do with a torch), you will have recrystallized the structure of the metal, and it will have lost its strain hardening (work hardening) and will again be easy to work. It doesn’t matter if you quench it, let it cool in sand, or air cool it after reaching this temperature, it will behave exactly the same (the lattice structures of the zinc-copper alloy that is brass aren’t susceptible to the same sort of modifications that the lattice structures of carbon-iron (steel) alloys are.)
To fix cracks: In my experience, brass is virtually impossible to fusion weld. We tried it over and over without any appreciable results. Instead, the best repair technique for cracks (or holes) is to use 45 % alloy silver solder. It has a coloring that is indistinguishable from brass, and since it’s silver solder, it will fuse brass below the parent metal’s melting temperature. It buffs out to look just like brass, and is easily filed or sanded to achieve a level surface. I have also found it useful for many other silver-solder type repairs.
On soft soldering, especially soldering the bezels with glass in them back to the main body: Soft soldering is extremely susceptible to any sort of contamination. You simply can’t get a piece too clean to try and soft solder it. If you wish to use cored solder, use only acid core. Don’t try rosin core electronics solder; it won’t work well. I find that cored solders don’t work as well for me. I prefer solid wire with a paste flux.
I could ramble on for a while longer about the differences between the two soldering processes, buffing and polishing, and sundry other items, but I’ll leave it at that for the moment. I share this information with you because I know the tribulations that you can go through learning this stuff; I simply didn’t have anyone around to show me any of it, so I had to pick it up through judicious reading and hard-won experience. When one of my students successfully turned out his first brass lamp, I was ecstatic. Brass lamp restoration is probably one of the hardest, most tedious jobs I have yet encountered in restoration. It can be daunting. But, the flipside is that it is extremely rewarding. Give it a try.