Friday, July 29, 2016

Repair Slim Gooseneck Table Desk Lamp with Slim Helmet Shade

The industrial revolution was a major turning point in world history. Mass production was possible and the standard of living rose sharply. Electricity played a major role in the quick evolution of manufacturing. Specifically, the light bulb created an opportunity for workers to extend the workday beyond the restricted daylight hours. Early styles of desk lamps were very basic. The objective was to cast light on the desk. There were no additional style points or pen holders.

A customer brought in this great example of an early slim gooseneck desk lamp with a slim helmet style shade on an UNO fitter socket. They wanted to use it full time and needed to make sure it was safe. It is probably about 100 years old now.


Initial inspection is good. This lamp has a polarized plug, so it must have been replaced in the last 30 years. The pull chain socket sounds and looks good. It has a nice click and firm recoil. The only concern with this lamp is the socket insulator looks really worn. If the insulator becomes brittle and falls apart in the socket, the terminals and wires could contact the metal shell and cause a risk of shock. Turning the lamp over we noticed the felt bottom has come loose and needs to be replaced.





The only lamp parts we need to repair this desk lamp is a new socket insulator and new round felt for the lamp base. This socket has a flared body like a Leviton Fat Boy socket. We are going to use a Fat Boy compatible socket insulator.

Socket Cap insulator

Fat Boy style insulator for early sockets with flared socket shells
First, we removed the lamp shade from the shade holder by unscrewing the set screws.



Next, we removed the shade holder from the socket. This UNO style holder simply unscrews from the socket shell.



Then, we lay the lamp on the table top and locate the "press" location on the socket shell.


With a thin flat head screwdriver, we apply pressure at the press mark and pry the socket shell from the socket cap.




The socket shell and insulator slide off the socket interior.




We unscrew the socket terminals and detach the cord from the socket. The insulators on this antique lamp are in need of replacement. First, we replace the socket cap insulator. The old one falls apart coming off the lamp.




The socket shell insulator looks just as bad. The new insulator is a firm fit, and slides inside the socket shell.




Now we are ready to reassemble the lamp socket. First we tie our UL knot in the lamp cord.


Then, we attach the socket to the cord. For polarity we always say: attach the smooth wire to the brass screw and ribbed wire to the nickel screw. This socket interior does not have a nickel screw; both are brass. To make sure the polarity is correct, identify the screw terminal related to the center post on the socket. This is the HOT side where the smooth wire connects. This leaves the outer screw part of the socket for the neutral or ribbed wire.


The socket shell slides over the socket interior. Cord slack is pulled back down and out the lamp base. We orient the  pull chain facing down and snap the socket shell back in place.




The shade holder and shade are placed back on the lamp.




The finishing touch for this repair is the new felt bottom. We turn the lamp on its side and lay it on the workstation. The old felt is peeled off. We use a wire brush to remove any glue or old felt on the base. The new felt is centered on the bottom.



Finally, we are ready to add a bulb and test the lamp.



Perfect! This lamp is ready for another 100 years. Total Cost <$5.00 Total Time < 30 minutes