Build a Curved Floor Lamp - Canadian Woodworking Magazine

Lighting Project: Dark winter evenings can be lit up nicely with this bent floor lamp. Great for reading and adding ambiance to a room, this project will also teach you a lot about bent laminating.

Build a Curved Floor Lamp

Build a Curved Floor Lamp



Photos by Steve Der-Garabedian; Illustration by Len Churchill

If you were looking for a project that would let you justify buying more clamps to add to your collection, this bent floor lamp is it. During my formal education there were two main areas that really opened my eyes. One was sharpening, and the other was the ability to bend wood. Straight-lined projects are good, but at some point you're going to want to go against the grain.
 
As with any project that requires hardware, in this case wiring, I made sure to have it on hand before starting. Wiring for this project is not hard to find. A quick Google search came up with lots of options for fabric cord sets. I like how pau amarello complements black walnut, so I chose a cord that was sunshine yellow. This set was less than $40.00 and came with 15' of fabric-encased wire, a socket, a switch and a three-pronged plug. Although wiring a lamp is pretty straight forward, if you're unsure at all about it, make sure to consult an electrician.

INFO:DIFFICULTY – 3/5, LENGTH/TIME – 3/5, COST – 3/5
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Forming a bend

My favourite method of bending wood is by bent lamination. Essentially, you take a solid plank, slice it into thin pieces, and then apply glue and bend it around a form. I made the form knowing that I wanted the body of the lamp to be 3" wide and stand just over 5' high. I calculated the spot where the cord would enter and exit the body of the lamp at 10" from either end. I made a curve that wasn't quite a section of a circle but rather had a little more of a tight radius near the base and smoothed out as it got to the top. I like to use MDF for bending forms.
 

Making a bending form

Anytime I need to make a form I start with a hardboard pattern, then transfer that to the material for the form, typically MDF. For the pattern I like to use 1/4" hardboard, as it's a little more robust, as well as being thicker to catch the bearing on a router pattern bit. To make the pattern for the lamp, I started with a 9' piece of moulding. There are many options for tracing curves, but a thin piece of wood from your scrap pile at a suitable length will work fine. Using two nails on the ends, I played with the curve until I was happy, then traced the line onto the hardboard. Using the band saw and sandpaper, I refine the shape until it is smooth, with no valleys, lumps or bumps. Making the pattern smooth is key, as any imperfections will get transferred to the form.

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Next, I attached it to a piece of MDF and, using Veritas offset wheel gauges, I created an outline approximately 1/8" away from the actual curve. Going back to the band saw, I cut this line, making sure to stay away from the hardboard pattern. Mounting a template cutting router bit in the router table, I adjusted the height to allow the bearing to ride against the hardboard pattern and cut the MDF to the exact shape. After removing the pattern and attaching another piece of MDF to the original, I repeated the process of tracing, cutting and routing the new piece. This process can be repeated as many times as necessary to achieve the width required.

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While the curve is the important face, the opposite face will need some attention, in order to make sure that clamps can be used without them slipping and sliding. You'll need to make the overall thickness small enough to accommodate the different sizes of clamps you have. A very important point is to make sure that you cover the surface of the bending form with a glue resist such as packing tape and/or wax before use.
 

Make the bend look natural

I started off with an 11' piece of black walnut that was just over 4" wide and 1-1/2" thick. I took 8' of it and milled it clean and true. Using the carpenter's triangle to help me keep the slices in the correct order, I set the band saw for a cut that was just thicker than 1/4". Keeping the order in which the laminations came off the plank allows for a seamless look when gluing the pieces back together.

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Slice It Up – A well-tuned band saw makes quick work of resawing the laminations from a single board. A cabinetmaker’s triangle ensures the laminations get glued back together in the order they were cut, to ensure grain and colour match.
 
I would first cut one slice on the band saw, put that piece aside, then use the thickness planer to smooth the remaining thick piece. Going back and forth between the two machines, I ended up with four slices. I ran these through the planer until each piece was 1/4" thick. When bending wood this way, the thickness will determine how easily you can bend wood around a form. The more radical the curve, the thinner each slice should be. As the bend for this floor lamp is gentle, 1/4" thickness is plenty.


Invisible wiring

Although the wire could be run on the outside of the lamp, running it through the body will make it look refined while also making it an interesting topic of discussion. We will need to drill a hole near the top of the bending form to let the cord pass through and not hinder the clamping process.
 
First, center the laminations on the form, and pick a spot near what will become the top of the lamp. Drill a 1/2" hole through the bending form at this point and center it across its width. Transfer this point to the inner lamination and drill a hole slightly larger than the diameter of the cord in order not to pinch it. Pick a spot near the base of the lamp and using the same drill bit make a hole in the outermost lamination. Using either a chamfer bit or a round file, smooth the edges of these holes on both the inside and outside to make sure they don't fray the cord.
 
Now that we have our entry and exit points for the wiring we need to create a groove in the middle two sections. The grooves are cut slightly past the holes where the cord enters and exits the body of the lamp. As the laminations were 1/4" thick, using a 1/2" straight bit gives us a groove of 1/2" by 1/2". Center the groove across the width of the laminations. [Illustration 1]
 
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Ease Sharp Edges – A countersink bit or a round file will help ease the sharp edges around the cord hole and ensure the cord doesn't fray.

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Rout Two Grooves – A router table makes quick work of creating a groove in the middle two laminations. The cord will run in this cavity.

Bring it together

In order to spread the clamping pressure evenly we need clamping cauls. In this instance 1/8" hardboard is perfect as it will bend nicely around our gentle curve. I cut four pieces that were just over 3" wide and approximately 6' long. Next I laid out the laminations on the bending form and placed the hardboard cauls on top to mark the spot where the cord exits the lamp near the base. I took all four cauls and drilled a 1/2" hole through them at this spot, again so that the cord would not hinder the clamping process.
 
Anytime I clamp I like to do a dry run. This allows me to see how many clamps to use, as well as setting their initial opening to fit over the assembly. In the case of bent forms this gives the added bonus of pre-bending the pieces. To keep the cord free of dirt, dust and glue I wrapped any portion sticking out the bottom with both masking tape and plastic packaging. I rubbed the remainder of the cord with wax so that glue would not adhere to it. Although stated in the sidebar, it is well worth mentioning again to put packing tape and/or wax over the bending form to stop it from permanently becoming part of the lamp. Use wax or packing tape on the first clamping caul as well, for the same reason. I removed the socket from the assembly and ran the cord through the cauls, the body of the lamp and down and out of the bending form leaving about 2' of length. I used all the clamps necessary to make sure that the laminations were pressed tight to each other. I let that sit for about 2 hours to let everything settle into the curve.
 
After covering my bench with paper, and laying out the laminations, I spread glue on both sides of the inner pieces and brought everything together on the bending form. I had pre-threaded the cord through the cauls and outer lamination to make sure things flowed smoothly during the glue-up. Using all the clamps I had previous used during the dry run, I clamped and made sure the stack was as lined up as possible. Inevitably there will be some slipping and sliding, however everything will be made flush soon enough.

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Glue 'Em Up – A roller helps apply an even amount of glue to the laminations to speed up the process.

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Even Pressure – Lots of clamps, and a few layers of 1/8" thick hardboard, ensure even pressure across the lamination.
 

Flushing it up

After the glue has cured, remove the clamps and inspect your work. Depending on the type of adhesive you used you might notice some spring back. This should be minimal and will not affect your design or any of the upcoming processes. I scraped glue off both edges of the assembly getting it ready for the jointer. As the laminations were longer than the bending form, I had small areas at the top and bottom where there was no clamping pressure and therefore the layers did not stick to each other. Using a band saw I trimmed these areas off.
 
Moving to the jointer I took a practice run to see if the cord would get in the way. Next, taking my time and using support rollers set at the bed height, I ran one edge over the blades several times creating a clean and flush edge. Measuring the distance from the center of the wire to the clean edge, I doubled the measurement and added a 1/16" to set the width of cut on the band saw. I then ran the piece through making sure to not cut the cord. One final pass on the jointer set for 1/16" cleaned up that freshly sawn edge.

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Joint One EdgeDer-Garabedian joints one edge of the lamination, while keeping the cord out of harm’s way.

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Trim the Opposite EdgeWith the band saw fence set about 1/16" wider than where Der-Garabedian wants the lamination to finish, he rips the length to rough width, then finishes the edge on a jointer.
 

A leg and foot

Taking what was left of the original 11' plank, I created a foot and leg to keep the lamp body from falling over. The leg I sized to 3/4" x 2-1/2" x 20", while the foot I milled to 1" x 1-1/2" x 20". I rounded over the edge of the foot that does not join the leg allowing it to sit flush against the floor and also give it a pleasant profile. Using two expansive dowels, 3/8" x 1-1/2", I found the center of both pieces and drilled, glued and attached them to each other.

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Simple and StrongA pair of fluted dowels keep the leg-to-foot joint tight. You can use a jig or dowel centers to drill the holes.
 

Adding angles

The tricky parts of this project come next. Placing the body of the lamp against my bench, I found a stature that was pleasing to the eye and clamped it. Next I clamped the leg and foot assembly to the body to mark the angle and position from the floor to attach everything together. I then cut the angle on the leg on the band saw and cleaned it up with a block plane. On a piece as thin as the leg, and a body with such a gentle curve, the attachment point on the end of the leg does not need to be curved as well.

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Dealing with Angles – Der-Garabedian rested the end of the bent lamination on the floor and clamped the middle of the lamination to his workbench, at a pleasing angle. He then positioned the leg-to-foot assembly next to the bent lamination at an appropriate angle, clamped it in place, and marked the angle on the leg.
 

Once the angle is cut on the leg, I used a square to line it up then copied the angle with a sliding bevel. Next, I drilled two holes in the leg that were 7/16" in from each edge and centered across its width, 3/8". Using a 3/8" brad point bit, I started the hole 90° to the angle, then as the bit started to cut I raised the drill to cut straight into the leg. These holes need to be approximately 1" deep.  I then carefully transferred these spots to the body of the lamp. As the leg is 2-1/2" wide and the body is 3" wide, the holes are 1-5/8" apart and 3/8" down from the top of the leg. This leaves plenty of room around the groove where the cord is housed. I marked these spots with an awl, and starting the drill at 90° to the body, and gradually shifted to the angle set on the sliding bevel. Use a depth stop collar on the drill bit so as not to bore through the body of the lamp.
 
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Angled Holes – With the joint angle cut, Der-Garabedian sets his sliding T-bevel to the angle between the bent lamination and the leg. This will give him a guide to angle his drill when he's boring the dowel holes.

Test fit the joint using two expansive dowels. Before proceeding with the final glue-up, plane and/or sand all the pieces and soften the edges. You'll need to get creative with clamping this joint. Making your own fixtures, or buying angle clamping jigs, glue and clamp the assembly as shown in the picture. An alternative method would be to position the leg and foot assembly and attach it with screws from the far side of the body. Countersinking the screws will then allow you to plug the holes with matching wood. The final touch is to round the bottom of the lamp body where it touches the floor using either a block plane or sandpaper.

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Clamping Contraption – Der-Garabedian uses some dedicated clamping cauls for clamping angles for this glue-up. He first clamps the cauls to the workpieces, then he adds the glue and applies pressure with the clamps.
 

Finishing up

While I previously sanded and planed the pieces, some areas needed a touch-up due to bumps and clamping scratches. I chose to go with a clear Danish oil finish, but any finish from shellac to polyurethane will work well. Once the oil had cured I added a fine furniture wax as a topcoat and rubbed it out with 0000 steel wool to give it a satin finish that doesn't show finger prints as readily as a glossy finish. I re-attached the socket, screwed in an Edison-style light bulb, and attached a black-caged light cover.
 
While overall this project is not very difficult, there are some tricky areas. With some patience and lots of double checking of measurements, completing this floor lamp can be accomplished quite easily. You'll have also justified the extra clamps.
           
 
STEVE DER-GARABEDIAN
steve_dergarabedian

info@blackwalnutstudio.ca













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