Concrete 3 Watt LED Light W/ Walnut & Balloons!





Introduction: Concrete 3 Watt LED Light W/ Walnut & Balloons!

About: Hi I'm Linn and on my Youtube Channel I have lots of great videos about building, construction and fun projects. You can also check out my site @

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 ), and this adds a really nice feel and brings out that dark color of the wood.

Step 9: Conclusion - Watch the Video!

For a much better perspective of all the steps and to see the final light fixture, make sure to check out the video!



  • Water Contest

    Water Contest
  • Oil Contest

    Oil Contest
  • Creative Misuse Contest

    Creative Misuse Contest

15 Discussions

Nice work!

Dinosaur Eggs! I know a kid who is obsessed with dinosaurs - this will make a great gift - thanks!

hmmm! will have to think how to get a small dinosaur (stuffie or model) inside the egg.

1 reply

You could take the balloon squish the animal in and then inflate tie off and coat in the mortar. This would make the egg with the dino inside as well as making a protection for the dino when the egg breaks

This is a great project! Thank you for sharing this with us. I can see some interesting possibilities for outdoor use. By chance, have you tried using solar panel pieces to recharge the battery?

I love that you show all of your experiments in your video. I am a teacher and I think that trying out ideas, and prototyping is an important skill that kids need to have. I may show your video to our kids. Here are some pix of kids working on their prototypes and final projects for daVinci-like machines (we went on a field trip to a daVinci exhibit)


You may want to explore using Hydrocal gypsum cement instead of mortar. it is easier to handle in thin sections, as it is stronger when set.

When you use a "dry mix" to get the look you want (either mortar or gypsum cement), the result may be weaker as there is not enough water present to complete the cure. The solution is to make with the dry mix as usual, allow to set, then soak the whole thing in a bucket of water for an hour before lifting out and drying.

Anther thing about the lithium battery: your charger "protects" the battery from over charging, but nothing protects the battery from over discharging (if you left the light on too long). You can buy modules (you connect between the battery and the LED) that control discharge as well as charging. Some batteries come with such modules pre-installed.

Could this work for outdoor lights? Maybe use a solar cell to recharge the battery and an option to angle the lamp down to illuminate a pathway?


1 year ago

Well done! I think when I try this I'll add some strands of fiber glass in the mortar to act as re-bar.

1 reply

good idea. make sure the fiberglass doesn't burst the balloon


1 year ago

great job. I like the look of it. How thick is the concrete that you would suggest? around 3/8 of an inch? The ping pong ball idea is excellent. well done

This looks really cool! The cover photo gives it a magical feel, because you can't see what's making the light.

I made a birdbath from concrete but added concrete dye. Unless you are a concrete purist (LOL!) this might be a great variation!?

Nice job on your Instructable too !!

No Instructable for the birdbath yet. Would be my first so really slow on the commitment.

P2201847 copy.jpg


The only thing I can think of would be to consider casting flat wires into the form so that you don't have to do it later. Also, gold leaf on the inside would be neat.


I'd do all the finish work on the base before attaching the shell.

If it's just morter, it won't take much to break, and the sand doesn't do a lot for you. As an option, use portland cement, and either burlap, or layers of cloth, soaked in cement paste. With no sand in it, you should be able to cut it with most saws. The cloth would fray on the cut edge, but a finger full of cement slurry would seal that. I'd still only use a blade I didn't care about.

Cement and cloth would allow you to wrap ribbons around the balloon leaving openings.

If you go with mortar, for a couple bucks extra a bag you can get white mortar.

You could also roll the wet mortar covered balloon in things like sequins, brightly coloured ground glass, pretty rocks....

I really like this. You broke down the steps nicely. I think I could get my son to figure out the electrical part for me.