book collections email follower instructable user
Picture of Silicon mold to cast a pencil Box

The idea was to cast own designs with concrete multiple times with a more durable mold and the same quality of each cast.

For this was the Design made with CAD, for myself I prefer Fusion360, so I will do this example with Fusion, but you can use any CAD program you like.

After this I checked the design and noticed a small mistake (made the bottom of the Box too thin). All in all I made good learning progress and in total I start to like makeing things with concrete.

This was my first ever concrete project and it was not easy to do the right decisions, because I had no experience. Starting with a book and lots of online tutorials I got a feeling for good and bad technics and methods.

With this method you can do concrete objects with cuts that are not possible with just the 3D printed molding form, because silicone is available in different hardness levels and due to its flexibility you can form it during demolding your cast. It is a method for casting concrete objects with one side molds.

Step 1: Preparation

Picture of Preparation
  • two component silicone e.g. Wagnersil
  • casting concrete e.g. Concrete
  • some cups e.g. cleaned yoghurt cups
  • some tools for mixing
  • water
  • gloves
  • scale (simple kitchen scale or post scale)
  • 3D printer or someone who can print your object
This turned out very nice- well done! I bet the surface is cold and interesting to handle, since it is concrete I bet the weight would surprise whoever picks it up for the first time.
Rudeldi (author)  Distracted Maker25 days ago
Thanks! Love the Surface! Weight of the 3D Print is 62g and the concret one 257g. :) feels solid!