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voxwal
03-17-2008, 12:10 PM
Rewiring Antique Lamp.

General: This ornate lamp is cast brass (manufactured in Germany according to an amateur antique collector, and probably over a 100 years old). It has a central column from which branch two brass “arms”, each of which supports a standard light bulb receptacle operated by an off-on pull chain..

Goal: Removal of old 110V. power cord (an insulated, stranded wire pair, covered with badly frayed, gold colored fabric) and replace with new 110V. cord.

Starting configuration: Existing 110V. cord entered lamp’s interior at base of lamp. There, with wire nuts, the cord was split into two pairs to rise within the center column to the point where the wire pairs entered the cast “arms” and to terminate in the bulb receptacles.

Progress so far: All the wiring (from where it enters the lamp’s base and then up to where the two pairs enter the lamp’s arms) has been accessed and removed simply by unscrewing the lamp’s base from the central column and then clipping the wiring where, from below, they entered the arms. (Yes, I know, I should have left useable “tails” of wire hanging down from there, but I assumed that pulling the wire out from the upper ends of the arms would be simple, so I failed to do that. Spilt milk.:()

At this point, I’ve now removed the two light bulb receptacles (at the ends of the arms) leaving approximately two inches of exposed cord extending up from each arm. Note: The arms are permanently attached to the lamp’s central column.

The Problem!: The wire pairs inside each of the two arms will not budge. Adhesion, corrosion, friction, crud, whatever.

My first attempt, using needle nose pliers, was to carefully wind the now exposed ends of the wire on to the pliers tip and, with a twisting or winding movement of the pliers, attempt to “winch” the wire out from the top. It refused to move even slightly. Further torque-ing began to break the stranded wire.

Next, to the kitchen, ho!, to bake the central column with it’s (non-removable) arms in a kitchen oven at close to 400 degrees Fahrenheit for about 4 hours. The hope: To break down the rubber (?) insulation to make it fall off the stranded wire as ash. The reality: The insulation became cracked and brittle but didn’t deteriorate enough to release the wire. (Yes, the oven treatment darkened the brass considerably, but it can easily be returned to its original luster.)

Next, I tried lubricating the wire with WD-40. No help.

It’s apparent that the interiors of the cast brass arms are not only rough, their inside diameters are probably, at max, between 1/4’ and 3/8”. Furthermore, each arm’s configuration is that of an “S” on its side (what a rancher would call a “lazy S”) so friction is doubtless a part of the problem. (NOTE: The length of each of the arms -- from where the lamp wiring enters the arm, to where it exits to connect to the light bulb receptacle -- is only about 13 inches.)

An additional hindrance to removing the old wiring from the arms with any sort of liquid is that there are ornamental brass leaves applied along the length of the arms and, in the process of originally affixing those leaves, small, almost invisible holes through the walls of the arms were created. Thus the WD-40 or any other lubricant (or destructive fluid -- coming up next!) leaks!

Next, "success through chemistry!": In an attempt to deteriorate the wire’s covering, I tried thin paint-and-varnish remover containing methylene chloride as its main “deteriorator.” In a “saucer test,” the remover dissolved the cloth covering into a yellow slurry, but seemed to only partially attack the rubber (?) insulation. In any case, at this juncture, I had difficulty properly drowning the wiring with remover because it tended to drain through the aforementioned holes and thus left most of the wiring untouched. It’s possible a paint remover ”bath” -- complete immersion of the lamp’s column and arms -- might still do the trick here, but paint remover with methylene chloride is at least an uncomfortable and at worst a dangerous material to fool with so am abandoning that route for now.


Next, I tried abrading or reaming the wire from the arms. This involved obtaining some samples of metal cable (wire rope) and, using an electric hand drill, twisting the cable into the arms, hoping the cable’s end fibers would grind the old wire into debris which I might be able to shake out of the arm. The abrading I’d hoped for did not happen. The end fibers of the cable are not stiff enough to create the “wire brush effect” I’d hoped for.

My next trick would be to obtain some piano wire; it’s quite stiff and quite strong. Some of the lower pitch wires are wrapped with a layer
of wire that coils around a single solid core wire. I’m hoping the core wire may be thin enough and stiff enough so that I can snake it past the old lamp wiring and perhaps then pull the balance of the piano wire (coiled part too) through the entire arm, dragging the lamp wire out with it.

Just dreaming: If a flexible shaft device existed -- one, say, 20” max in length, with a max shaft diameter under 1/4”, which could be driven with a Dremel tool or 1/4” electric drill, and be fitted with a carbide or carbor- undum grinding tip that would remain centered within the arm (so as not to cut through the wall of the arm) I suggest might do the job.

Come on, you thousands of inspired creative and inventive people! Accept the challenge! Forward! Hellllllppp! Out of the abyss! Out of the darkness!! Let there be... light!!!

HayZee518
03-17-2008, 03:55 PM
a BUNN coffee maker has a tightly wound spring that they use to clean out the siphon arm of the scaled lime inside. quite possible you can use this in a portable electric drill to clear out the arms. regular light machine oil attacks rubber and makes it slimy after a while - try this. acetone attacks most plastics. paint and varnish remover has toluene and methylene chloride mixed in it. a standard fish tape (electricians use this) is made of a spring steel, 1/16" X 1/8" wide. try jamming this into the tube and forcing out the wire.