Cement Molds

Remember as a kid (possibly an adult) playing in the sand with a plastic bucket. You used the bucket as a mold to build sand castles. All you have to do is fill up the bucket with sand, flip it over, then remove the bucket. This is exactly the same concept but I am adding cement to the mix to form a permanent cement block.

I printed a shell on spiral vase mode to be used as the mold. I used a 1.0mm nozzle to get a thick 1.2 mm extrusion width.

Poured in the cement.

After a day or two, the mold is ready to break open to show your custom cement block. The best way to release the mold from the cement is a torch. Once heated the PLA shell will peel right off with very little effort.

As you can see the very tip of the model did not survive either attempt. Cement is not strong in tension so small features like the tip of the cone break off easily. This is something to keep in mind when modeling a cement mold.

I would not say that either of these came out as a success. But they prove the concept can work with some fine tuning. I need to work on my mixing ratios of cement. I could not justify using our kitchen measuring cups, so I just eyeballed a 2:1 ratio of sand to cement. Then added water until it looked like a good consistency. I should have been more exact. This is not the best model to use as a cement mold either.

The application of this could be used for bird baths, flower pots, garden gnomes, Or even multiple cement blocks made to fit together.