Introduction: Pipe Table Lamp With Cement Base
Based on a few other designs I've seen, I made this table lamp out of galvanized pipe, with a cement base and an embedded switch. The shade is also homemade from a couple of wooden embroidery hoops and some watercolor paper.
The project consists of 4 parts:
- Wire the switch
- Cast the cement base
- Attach the pipes and lamp socket
- Create and attach the shade
- 12 ft lamp cord (Satco part number 90-1415)
- Single throw single pole switch
- Plastic tub as a cement mold
- Caulk to seal the hole in the mold
- Cement/Concrete mix (I used Quickrete ready to use concrete mix)
- Lamp socket (Satco part number 90-407)
- 3/4" galvanized floor flange (with screws)
- 12" or longer 3/4" galvanized pipe nipple
- 2x 3/4" galvanized 90 degree elbows
- ~3" galvanized pipe nipple
- 3/4" galvanized pipe closed nipple
- 1-1/4" to 3/4" galvanized reducer
- 1-1/4" galvanized pipe closed nipple
For the shade:
- 1-1/4" galvanized floor flange
- 2x 7" wooden embroidery hoops
- Large sheet of watercolor paper or similar
This was my first project with cement, and this will be my first instructable. Let me know if you have any questions, and also any tips to share. And a big shout out to the great folks at Pacific Supply on 12th Ave E in Capitol Hill, Seattle. They're the best hardware store in town!
Step 1: Prepare the Mold
You're going to need a container to use as the mold for your cement. I first tried a yogurt container, and that resulted in failure: your container should be large enough to support the forward weight of the pipes. Notice that my container ended up being a longer shape that allows for the pipe flange to be seated at the back of the lamp so that there's a nice forward piece of the base to support the weight.
So, my container was from gelato. Poor me, I had to eat the whole thing before I could start this project!
I recommend a plastic container, and if you want the wire for the wall to come right out of the back like mine, you'll need it to be disposable and easy to cut.
Start by making a hole for the wire using a utility knife or similar. keep it as small as possible or you might have leakage of cement.
Slide as much wire as you need into the container. I used a 12 ft. cord so it would be plenty long even after some if the length disappeared into the lamp. String the wires through your pipes to make sure you're leaving enough slack to work with. I put a piece of masking tape on the wire to indicate where it would need to exit the cement.
Now caulk around the opening where the wire goes through the container to avoid leakage. (Note, you might want to re-check your caulk after assembling the wiring, or just wait until the wire is assembled to do the caulk.)
Step 2: Assemble the Wiring
The wiring from the wall will go into the cement, where it's hooked up to the switch, and then out through the middle of the pipe flange, where it winds through the pipe to the end where the socket will be. You can skip the switch if it makes you nervous, or go ahead and get a simple in-line switch that basically snaps onto the cord further down.
If you choose to use a switch, you'll need to cut one part of the wire and attach it to the screws on the switch. On standard cables like this, one side if always "marked," usually by a ribbed texture instead of smooth, to indicate the neutral wire. Never cut the marked/ribbed side! Only cut the smooth side, which is the hot wire.
You'll first separate the wires by cutting between them using a utility knife, then cut the hot wire and attach it to your switch. I added a twist tie to keep the wires under control while I poured the cement.
This whole process is done inside the container.
Step 3: Mix and Pour the Cement
Now you're ready to pour the base!
Remember, cement powder is not good for you. Wear eye protection, gloves, and a dust mask when working with it.
Update: Per the comments, the mix I used was Quickrete Ready to Use Concrete Mix, in a yellow bag. Not sure if there's a better option out there.
I had never mixed cement before, and couldn't find much insight into mixing small quantities. I don't think I did it quite right, but it worked out alright anyways. I used approximately a 4:1 ratio of mix to water. Mixing was made easy by pouring the mix and water into a gallon ziploc, sealing, and then just mushing it in the bag. You want the consistency to be thick, not too watery. I heard things like "consistency of oatmeal," but everyone eats their oatmeal differently, so go figure that one out.
Using a paper cup or similar, scoop the mixed cement into the container, holding the switch out of the way. Once you've reached the desired depth, tap the container on the table to remove air bubbles and smooth the top.
Now push the switch down so it's level with the surface. Careful: if your cement is on the thin side it might sink it a bit, so you'll want to check in 30 minutes to make sure it hasn't moved.
At this point, you'll also want to place the flange on top of the cement, and push four screws through the holes. Rather than drill them into cement later, we're just letting them set inside the cement.
Despite what you might expect, cement doesn't "dry" the way paint does. It sets, and it only does so in the presence of some moisture. I loosely replaced the top of the container to hold in moisture. I made a hole so the cord could come through. Place this whole thing somewhere that won't be damaged if it leaks some cement around the cord.
I let this dry for a couple days, and then unmolded. You have to cut or break the plastic around the cord.
Step 4: Attach and Wire Pipes
Once your base is ready, you need to attach the pipes to the flange, stringing the wire through each as you assemble. You can see the layout of pipes I chose, but be creative! The only important part was that my light socket fit inside a 1-1/4" width of pipe, so the end of my lamp has that reducer that goes from the 3/4" pipe to a 1-1/4" nipple that hides the socket.
Once the pipe is assembled, wire the loose end of the wire to the socket (be sure to wire the smooth side to the hot screw), and then secure the socket inside the pipe. I did this using more caulk, but it would probably be more secure with some super glue or similar. Once that dries, you're done! Just screw in a lightbulb, plug it in, and flip the switch.
Step 5: Create and Attach the Shade
If you use a low-wattage bulb, the lightbulb could remain bare, but I wanted more light, and decided to make a shade. This was super simple: two 7" wood embroidery hoops ($1.99 at a local fabric store, but more expensive on Amazon), which secure a length of watercolor paper (picked up at a local art store). I glued the seam with a tiny bit of wood glue to keep it tight.
The joy of this design is you can pick a different color, or use a fabric covering, etc. You could even paint your shade! Maybe paint some trees on the inside with black paint and see the silhouette shining through.
To attach the shade I ended up using small screws driven into the inside of the top of the hoop, and then some thin wire I had to secure that to the extra pipe flange. Without the flange it was too hard to secure the shade. Better ideas are welcome in the comments!
That's it! The end of my first instructable. I hope it's useful. Please share your comments and I'll do my best to update.