Plastic bowls to use as forms — I bought this set of plastic stacking bowls, but you can get creative with molds!
Cooking oil — I used canola oil, but almost any oil will do the trick.
White concrete mix — I used leftover concrete countertop mix from our kitchen countertops, but you can usually find white concrete at your local hardware store.
Drill with mixing attachment — this is not 100% necessary for this small of a project, but will make the mixing an easier job.
Bucket — for mixing concrete in
Hammer — for tapping the sides of your molds to help settle air bubbles
Rocks — or any other weighted object to hold the smaller mold in place
Sand paper — I found that 120 grit was good to sand any bigger areas quickly and finished with 400 grit for a very smooth finish.
These will help the forms stay equidistant apart from each other so you won’t have too thick or too thin of a bottom. The nails should be as close to the top as possible. You can see in our process photo below that we were working ahead and gathering our rocks for step 4.
Nonstick cooking spray or canola oil works for this. Make sure to coat any part of the form that will be in contact with the concrete. Typically this will be the outside of the smaller mold and the inside of the larger mold.
Pour the mixture into the larger bowl. Pour it about 3/4 full If you want the form to be all the way full, or less if you want a bowl with lower sides.
Do this for about a minute and then press your smaller bowl inside the larger bowl that is filled with concrete. Hammer it some more to minimize air bubbles. Fill the bowls with rocks to keep the top form in place.
They should pop out without too much effort.
We used 120 grit for the very bumpy areas and worked our way down to 400. It’s a good idea to wear a mask during this step because concrete dust is a known carcinogen.
And that’s it! A simple project with a beautiful result.
This post was written for the Collected Eclectic blog.
Collected Eclectic was a passion project focused on recording the process as Grace and Michael van Meurer transformed their builder grade home in to something special.
124 blog posts were published between 2018 and 2021. Explore the complete Collected Eclectic archive here.
Learn more about the project here.