Concrete 3 Watt LED Light W/ Walnut & Balloons!

Today I'm making this rather unusual looking lamp out of concrete and walnut with the help of balloons to accomplish the shape. It has a 3 watt diffused LED light, a rechargeable battery, and no visible wires. I think this lamp makes a pretty neat accent lamp, however the way the light is focused it also works nicely as a desk lamp or anywhere where you want some more lighting.

Step 1: Balloons!

Balloons are what got me started on this project. For a while now, I've been thinking about the possibilities of molding concrete around balloons.

Not sure why, but I love the idea - also, I had no idea if it was going to work, but not give it a try!

I'm using mortar for the mix, because it's pretty smooth, and to start with I figured I would make a relatively stiff batch, not too loose. I placed the balloon upside down in another container to keep it in place, and then I started patching the mix on top of the balloon. I made a hole at the top so the wire would have somewhere to go.

Step 2: Different Tests

Pop! About 4 hours later, I popped the balloons and the mortar was nice and dry.

I loved the concept! So I made more - which is the beauty of concrete, so cheap and available, perfect to experiment with. I tried making making the batter wetter and dryer, with different results.

I realized that the wetter mix, the less worm holes and interest on the inside. The wetter mix produced a super smooth and beautiful inside, but I thought they were almost too nice, I missed the pattern of the initial tests. So I decided to use one of the first tests that had that look I liked.

Step 3: LED Lights

For a light, I'm using a 3 watt LED light, and I'm cutting up a piece of aluminum cause they can get hot. I used some thermal adhesive to secure the light to the aluminum heat sink.

Step 4: The Base

For a base I'm figured a nice piece of thick walnut would be beautiful, however any piece of wood would be nice, In terms of a shape, figured a triangle would contrast the round bowl a bit, so I went with that and cut it out on the band saw.

To provide greater contact between the two materials, I carved out a little bowl in the middle of the walnut.

On the other side of the wood, I drilled and chiseled out enough space for the electronics and drilled some holes for the different wires.

Step 5: Electronics

For this lamp, I'm using one 3.4 volt, 3 watt LED, one 3.7 volt 1200 mA rechargeable lipo battery, an Adafruit lipo charger, a small switch, a 1 ohm resistor and a micro USB connection so you can plug any phone charger in to recharge it.

There's a basic drawing showing how I connected them all.

So I assembled the unit, soldered the wires together, secured the components with a little hot glue. Then tested it out, and it worked!

Step 6: Securing the Light and the Bowl

Now I decided to put the light pretty high up inside the bowl, so securing that with epoxy, and then the wires come out on the other side. I also epoxied the bowl to the base, and that created a very sturdy connection.

Step 7: Covering the Base, the Wires & the Light

To cover the base I have some thick canvas here, and I'm just using hot glue to secure that as well.

Now once all the parts were connected and in place, I mixed up some more mortar and covered the wires in the back. To create a cover for the light, I'm actually cutting up a ping pong ball in half, and epoxying that in place too.

Step 8: Finishing the Wood

To finish the walnut, I'm using some of my tung oil beeswax polish which I make (available at http://darbinorvar.com ), and this adds a really nice feel and brings out that dark color of the wood.