This lamp came about after I found a glass shade in the scrap pile at my local glass studio. It was twice as long but had some imperfections in the glass and wasn't usable for them. I cut the glass down, polished it flat, and made a wood base to mount the fixture. It's a quick and simple bedside lamp using materials that I had on hand (scrap wood, fixture, chord, bulb, cork mat).
This Instructable will show one way to fit an imperfect glass cylinder onto a wood base, with a strip of cork acting as a buffer in between. I wouldn't use this method for a hanging light, but it works just fine for this small table lamp.
Step 1: Glass Lamp Shade
Originally this glass cylinder was about 12" long. It was thrown away because there were imperfections (tool marks, bubbles) in the middle. I cut it down on a diamond saw just above the imperfections, and then polished the bottom flat using a glass lapping wheel.
This shade is 4-3/4" Tall x 4" Wide x 1/8" Thick
This lamp could be made using an old bottle or mason jar, or a glass shade from another lamp. However, the shade should be open at the top so the heat of the incandescent bulb has somewhere to dissipate. A clear piece of glass could be sandblasted, to give it a frosted look, which diffuses the light.
For a standard light bulb, I recommend a shade that's at least 5" tall, so the top of the bulb doesn't poke out of the rim of the glass like this lamp.
Because this shade is so thin and imperfect, simply turning a piece of wood to fit inside would result in a very loose fitting shade. Making the fit too tight would probably result in the glass breaking when pressed onto the base, especially with a thin glass piece. But with a thin strip of cork, the glass will fit snugly onto the base.
Step 2: Turn and Fit Wood to Glass
It's best to turn the base after you have a glass shade to use.
I started with a square piece of olive wood scrap, just over 1" thick. The block is mounted to a face plate and roughed in. I wanted the outside of the glass to be in line with the outside of the base, so the wood is turned until the O.D. matches the glass.
A step-down is cut into the wood so the glass will fit over it. The size will depend on the strip of cork being used in a few steps, but leaving a gap between the wood and glass that's 1/8" - 1/4" will work.
Step 3: Drill Holes for Fixture
In order to mount the ceramic fixture, a few holes need to be drilled through the wood. One should be the diameter of the threaded rod that attaches to the fixture. The other is on the bottom of the base, a slightly larger hole is wide enough for the set nut to be countersunk in the base.
That's all that's needed to secure the fixture, but because the chord passes out through the bottom, a channel needs to be cut in the base, large enough for the chord to pass out the side. I used a round gouge and cut the channel in the wood by hand.
Step 4: Mount Glass to Base
To mount the glass shade to the base, I used a thin strip of cork and adhered it to the glass using 3M Super 77 spray adhesive. The strip of cork is cut from a thin corkboard with a utility knife. After it's glued to the wood, the cork is sanded down until the glass shade has a tight fit.
With the fixture mounted, and the glass shade ready to install, the last step is wiring the light.
To wire the lamp, you need a length of chord, a plug, a socket, a bulb, and an inline switch (all standard parts at the hardware store). The socket has a threaded rod that passes through the base, held on with a set nut. The two wires in the chord are shoved through the threaded rod and screwed onto the socket for power and ground.
Step 5: Wired and Finished Lamp
The bulb I settled on is a 60 watt incandescent, which through the white glass, is a comfortable brightness for a bedside lamp.