Awhile ago I watched a video of someone making candy lego bricks but they didnt interlock. I wanted to try the project and have the bricks interlock. I kept thinking about this project and ended up wanting to try it with concrete and not chocolate.
Step 1: Tools & Materials
1. silicone mix
2. concrete mix
3. sand paper
4. lego base plate
5. lego bricks
Step 2: Mixing the Silicone for the Mold
I decided to make my own mold for this project so I could make various sizes of lego Bricks. My mold holds one pound of silicone which is 16 oz. so you need 8oz of part a and part b. I accidentally did 16oz of both. Next mix the two parts really well so you will get a correct casting. I poured the silicone mix as high as possible to get the bubbles out. After all the silicone was in i tapped the edges to get the air bubbles to the top.
Let the mix try for 24 hours. Once it was dry the legos came out very easily.
Step 3: Mixing the Concrete
I used quikrete 5000 but if I did this again I would use a countertop mix because this one had a lot of big rocks. I separated the big rocks from the mix with a sifter. I added water to the mix and tried to get an oatmeal texture. Next I scooped a little bit of concrete and pushed it down into the mold. I used my hand but you should use a popsicle stick to really push it into the mold
Make sure to vibrate the mold to get air bubbles to the top
I used a base plate to put in the back of the mold to try to add holes so the bricks would interlock. You will want to weigh it down with a heavy object.
Let it dry 24 hours
Step 4: Sanding the Blocks
I honestly was surprised it even remotely worked. Some came out better than other but I'm calling this a success. I sanded some of them down and tried to build a tower.
Step 5: Enjoy Your Concrete Lego Bricks!
Overall, I am very pleased with how these came out. It was mostly an experiment to see if they would even work or not. I really wanted them to interlock like real legos. They sort of did but i think in the future if i spend more time leveling the mix in the mold then it would work better.