Introduction: Make Doorstop Out of ShapeCrete

About: Founding board member of theMakerStation, a new makerspace in Marietta, GA

Our local makerspace, the Maker Station in Marietta Georgia, recently participated in an Instructables build night for ShapeCrete moldable concrete supplied by Cheng Concrete.

ShapeCrete has an awesome projects website with tons of inspiring ideas. I liked this doorstop idea but though it would be more fitting to make one of the letters M-A-K-E for our makerspace. I decided to make one based on the ShapeCrete tutorial:

Step 1: Prepare the Mold

1. Used some super thick roofing foam block insulation that had been found discarded behind our makerspace"
2. It was at least 4 inches thick
3. I forgot to take a picture but I basically drew out the block letters on the foam board with a Sharpie marker by hand.
4. ShapeCrete recommends using 2 inch foam block insulation and printing out the letters with a printer to make a stencil
5. After marking out the letters M-a-k-e and making sure that they all touched, I started to carve them out using a dry wall saw to cut through the thick foam. I didn't get pics of this either
6. After cutting, I put the mold face down on a piece of scrap oriented strand board (cheap plywood) and then used hot glue to secure it to the board and also to add the "holes" for the letters "a" & "e". Again no pics of this step

Step 2: Prepare the ShapeCrete Mix

  1. We neglected reading the instructions on the Shapecrete bucket and simply started adding water to some of the powder mix
  2. If the mix seemed to watery/runny, we simply added more powder
  3. We used an old discarded egg beater and stick to mix it all up
  4. The egg beater worked great

Step 3: Pour the ShapeCrete Mix Into the Mold and Then Let It Cure

  1. Didn't get any action shots but this is what it looked like after pouring the mix
  2. I used a flat stick to trowel it and make sure concrete was pushed into every nook and cranny of the mold
  3. After cleaning up, we let this sit in the mold for about a week due to other activities

Step 4: Remove the Mold and Sand It Down

  1. Pretty much destroyed the mold getting it off the casting
  2. Once again I used the drywall saw to cut the foam insulation mold off
  3. This step was too messy for photos
  4. After removing all of the insulation, I used sand paper to get the remaining bits of foam off and do general smoothing to the edges
  5. I started with coarse 60 grit sand paper and absolutely destroyed it in the process
  6. I followed up with 150 grit fine sand paper to finish it off
  7. I then used a broom to dust it off, followed by an air compressor to get it really clean

Step 5: Paint

  1. Last step was to apply some paint
  2. I used spray paint found in a bin at our space
  3. It had to be red

Thanks Instructables and Cheng Concrete for supporting these Maker Space Build Nites! I would have never done a project like this with their support.


If you are in the Atlanta area, come check out our makerspace in Marietta.

Details at:

Concrete and Casting Contest

Participated in the
Concrete and Casting Contest