Tim's Desk Sized Serpentine Lamp
This storyline explains the making of a desk-sized, mid-century serpentine lamp. The serpentine lamps are beautiful, unique designs which are quite intricate to build. This rendering illustrates the finished lamp design; it is being built in black walnut and the general measurements are approximately 16 1/2" to the bottom of the shade, 7" width for the widest part of the lower serpentine section and a base 2" high x 6 1/2" diameter. The upper portion of the lamp body is a polished brass cone and an exposed, polished brass tube runs lengthwise through the center of the lamp. The 4 serpentine sections are built individually and joined in the center of the lamp by small wooden turnings which are center-bored for the brass tubing. The base of the lamp is weighted for stability and the electrical cord exits through the back of the base. The lamp shade will attach by a harp with a matching walnut finial and the lamp will have a 3-way roll-type switch on the socket; all the hardware is brass. Let's get started....
First up, a trip to the mill for the walnut. Here you can see the boards selected; the long board measures 2.1" thick x 8" wide x 76" long and it will be used to make the serpentine sections, center turnings and finial. The other board measures 2.25" thick x 12" wide x 34" long and it will be used for the base.
A round blank is needed to turn the base and here you can see a section from the larger board being cut on the band saw to a more manageable size.
... and here you can see the round blank being cut for the base, it's also cut on the band saw and once cut the base is ready to be turned.
Before cutting the serpentine sections, a template is needed so each of the finished sections are identical. This is important because sizing and alignment of the serpentine sections is critical. Also, the serpentine sections have areas which are quite small and could be susceptible to breaking across the grain. To make these areas more robust, each of the serpentine sections will be built up by 3 laminations of the walnut where the grains are offset and the glue joints provide added reinforcement.
When making the template for the serpentine sections, it's important to take nearly exact curves from the drawings so the balance isn't lost or distorted. I start by drawing a 1/4" grid on the material for the template like this.
Then points in the drawing are transposed to the grid and the curves are drawn freehand between these points to form the rough shape like this.
This rough shape is cut out using the bandsaw...
... and the rough shape is trimmed and sanded into the final shape.
Because 2-3 curved areas in the serpentine shapes are thin, they need to be made more robust. This is done by laminating the walnut which allows the wood grains in the different layers to be offset and the glue seams between these layers ads strength/rigidity. The serpentine sections will be 3/4" thick and made up of 3 layers of walnut so the long board (shown above) needs to be cut into thin (1/4" thick) boards for laminating. The sides of this board are quite rough so first it is cut into the correct width, here you can see that being done on the band saw.
Next, the board needs to be cut into thinner sections and here you can see it being re-sawn to 3/8" thick boards.
Next, these thinner boards are flattened and surfaced to 1/4" thickness and here you can see that being done with a surface planer. Once the boards are surfaced they are glued together to form the lamination then the serpentine sections are cut out using the template above.
Due to the shape of the base, it needs to be turned bottom-side first and the edges need to be cut/finished at the same time. To accomplish this, the base needs to be turned using a faceplate which holds the walnut base on the lathe. The faceplate is screwed to the base so it can be easily removed once the turning is done but we don't want screw holes in the top of the base so a sacrificial wooden surface is glued to the top of the base and the faceplate will be attached to this sacrificial surface. Here you can see the walnut blank for the base being surfaced flat so the sacrificial surface, which is pine, can be glued to the walnut. In the next photo you can see the sacrificial surface being glued to the walnut. Once the bottom and sides of the base are turned to their finished shapes/sizes, the faceplate is removed, the base is turned around and mounted to the lathe by a 4-jaw chuck which doesn't need screws to hold it. The sacrificial surface is then removed from the walnut by turning and the walnut is turned down to the correct thickness for the base; once this is completed the base is ready for finish.
Here is the faceplate mounted to the block for the base.
... and here you can see the base mounted to the lathe by the faceplate.
Here you can see the base partially turned; the diameter has been cut to size and the recess under the base is being cut. This recess holds a cast iron weight which helps stabilize the lamp and here you can see it being checked for size.
Here you can see the recess has been sized correctly and the base has been rough sanded.
Next, a hole needs to be added to the center of the base for the brass tubing that runs vertically through the lamp and carries the wiring. Here you can see this set up.
... and here is the base after the hole has been made. This hole needs to be tight fitting around the brass tube so it looks neat, the hole is 1/64" larger diameter than the brass tube.
Next, the sides of the base need to be shaped. These photos show where the thickness has been set and the angled sides have been cut and sanded. It's now tie to remove the faceplate, flip the base over and cut away the sacrificial surface to finish the base turning.
Here you can see the faceplate has been removed and the base has been turned around for finishing the top.
the sacrificial surface gets turned away and the thickness of the top is brought down to correct size.
...and here you can see the base finished turned and sanded.
last thing to do to finish the base is drill the hole for the cord and here you can see that's been done. The brass tube that will run through the center of the lamp is also test fit, looks nice. The base is now completed except for finish.
Laminating the walnut boards was discussed earlier but here you can see them being readied for gluing. The boards are checked for imperfections then lightly scraped to remove any small ridges from the surface planer. Also the edges are lightly sanded to remove splinters that could prevent the boards from mating closely against each other. The walnut boards are quite thin and bend easily but the finished lamination needs to be very straight and flat. To accomplish this, the boards are glued and clamped in a make-shift press and here you can see a pair of heavy oak boards which will be clamped against the walnut. These oak boards will be clamped at the top and bottom edges to distribute clamping pressure evenly; you can see this set-up below.
... and here you can see the walnut boards glued up and clamped between the oak boards. The oak boards are very flat and straight and the walnut lamination looks great.
Here you can see the laminated sections out of the clamp press. the edges need to be cleaned up and the face-grain sides need to be sanded.
the serpentine sections will be joined in the center by a 1" diameter round wooden tube and the inside edges of the laminated sections need a 1" diameter cove rounded into them so the center tubes will seat well; here you can see that's been done.
Once the laminated boards have been edged, sanded and routed it's time to cut the serpentine sections and here you can see that's been done. These are only rough cut at this point; the curves all need to be smoothed then all four sections need to be sized to the exact same length. As the serpentine sections were being cut, the seams or joints between laminations were checked for voids and none were found. The walnut sections were also checked for imperfections in the wood and none were found.
The top portion of this lamp design receives a polished brass neck which is approximately 2 1/2" long. The top of the neck is 7/8" diameter and the bottom is 1 1/2" diameter. This piece gets cut from a heavy brass casting which is shown here. The brass neck will rest on a small walnut cap at the top of the serpentine sections and the brass had to be made before the walnut cap so the cap could be sized correctly. More about this when the cap is made.
...and here you can see the polished brass neck ready to fit to the lamp.
The top of the neck will receive a polished brass check ring which is shown below; this is what the neck section will look like on the lamp.
The serpentine sections are held together in the center of the lamp by two small wooden tubes, one at the top and one approximately mid lamp. Here you can see these pieces are made.
The piece for the top of the lap also serves as a seat for the brass neck and here you can see the two pieces test fit together.
A brass tube runs vertically through the center of the lamp (and carries the wiring to the socket) so the center of these tube pieces need to be bored to allow for the brass tube and they need to align correctly. Here you can see them being test fit and alignment checked.
Before the serpentine sections get final shaping and sanding, the lamp needs to be test fit to see where adjustments are needed in each serpentine section. Any small adjustments needed are done when the serpentine sections are finalized. Here you can see a couple photos of the lamp being test fit together before the serpentine sections have been finish-shaped or sanded - everything looks good - time to finalize the serpentine sections and begin gluing the lamp together.