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Did you know you could use LEGO Bricks to form concrete? I had so much fun making this funny little nightstand that looks like a robot. I was skeptical about how well this idea would work, but everything went smoothly and Lego-formed concrete is my new obsession.

Step 1: Supplies + Tools

LEGO Bricks
Available at Amazon
I used the classic LEGO bricks to make the mold. I raided my parent's attic to retrieve my childhood stash and purchased a few new sets. Purchasing all new bricks for this project might be a bit expensive, so I'm working on a post showing how the nightstand could be cast in sections to reduce the amount of LEGO needed.

3/4" Melamine Board
Available at the Home Depot
Melamine board is particle board with a smooth laminate surface. It's a great product for making a concrete form work. I bought a 4' by 4' sheet and had four 2 1/2" strips cut at Home Depot.

Quikrete Countertop Mix
Available at the Home Depot
I prefer the Commercial Grade Quikrete Countertop Mix for these type of projects but Quikrete 5000 will work just fine as well.

Hot Glue Gun
Available at the Home Depot
I used a hot glue gun to glue the LEGO bricks to the board. Don’t worry – the glue will peel off later.

Step 2: Layout the Mold

Layout the design and build the mold 3 bricks high. Place temporary spacers to get the inside and the outside rings in the right position.

Step 3: Glue Down the Legos

Use the hot glue gun to glue the Legos to the melamine board.

Step 4: Finish Building the Mold

Build the mold up brick-by-brick. When you get to the top, place some support braces to keep the walls from bending out under the weight of the concrete.

Step 5: Mix + Pour the Concrete

Mix the concrete and spoon it into the form. After you have put in about 3 inches of concrete, use a stick to push the concrete into the corners and vibrate the air bubbles out of the concrete. Repeat this process until the mold is full.

Step 6: Level + Smooth

I used a trowel made from Lego bricks to level and smooth the concrete. Don't worry about this too much because the melamine side of the mold will be the front and will come out nice and smooth.

Step 7: Let the Concrete Cure

Let the concrete cure for at least 20 hours before removing the mold.

Step 8: Remove the Mold

Removing the LEGO bricks can be a bit time-consuming. Remove the upper layers and then cut the glue with a knife. Flip the block over and start removing the bottom bricks. You can use long nose pliers to remove the bricks from the bottom, but be careful not to scratch or bend the plastic bricks.

Step 9: Add a Drawer + Legs

You can make a wood base and drawer for this nightstand or use LEGO bricks. The concrete part is quite heavy, so you might want to glue the LEGO together if you do use them.

Step 10: Clean the Legos

Most of the dried concrete flakes off the LEGO bricks. Some small pieces can be scraped or brushed off with a toothbrush. Only use cold water and mild, non-abrasive soaps to clean the bricks. If you have a mesh bag for laundering delicates, you can place the bricks in the bag and wash it in a washing machine with the water temperature set to cold. Do not use hot water or you will warp the bricks.

Step 11: Finished!

Good luck making your own concrete nightstand and please email or tweet photos to @benuyeda or ben@homemade-modern.com. For more DIY ideas and projects, visit us as HomeMade Modern.

<p>So cool! :)</p>
<p>This is so cool! I love the finished one with the multicolored lego legs and drawer! You should definitely enter this in the concrete and casting contest that's going on right now! https://www.instructables.com/contest/concrete2014/</p>
<p>Wow! Lego and concrete! Love the combination.</p>
<p>I like this, you can create some fun forms with LEGO bricks. </p>
<p>Awesome use of LEGOs! I had no idea they can be used as a mold like that. Your pictures look great and your work is nice and detailed. These concrete instructables are all so impressive, and this one really stands out against the rest! </p>
<p>how are the legos after party like that ? im conserned</p>
<p>You'd probably loose a few bricks during the process, especially if you are not building just straight walls.</p>
Love the Lego mold idea. Would it make molds with undercuts possible?
<p>Super clever!</p>
<p>That looks awesome! Do you remember what the dimentions were of the rectangles you used?</p>
<p>Wow, this is amazing! What a great way to reuse old Legos. </p>

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Bio: HomeMade Modern is an online design source that publishes easy-to-follow, DIY recipes for creating modern home furnishings. We provide creative ideas for making affordable alternatives ... More »
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