Video Tutorial: Casting Concrete Objects with Silicone Molds


This video features theSilicone Teardrop and Silicone Dodecahedron, but the tutorial will apply to any of our other silicone molds.

Video Transcript: Today, we’re going to make some concrete objects using silicone molds.

I’ve laid out here all the materials that we’re going to need. I have here two different silicone molds. I’m using Mann Industries universal mold release. Mold release isn’t really necessary when working with concrete, but using it will slightly prolong the life of your mold over many many castings.

We have our two molds, mixing stick, for small objects like this I like to use Buddy Rhodes Artisan Mix. We also need a mixing bucket and some water. I’ll add a little bit of water to the bucket first to reduce the amount of dust when scooping in the concrete. Add approximately how much concrete mix you think you’ll need. Slowly add water as you mix, being careful not to add too much. If you do, just add more concrete to thicken it up.

Prep the molds with a quick spray of mold release. For some molds, I like to spoon the concrete into the mold a little bit at a time. In between scoops, tap the mold down a bit. This will settle the concrete and reduce air bubbles trapped on the surface. Then top off the mold and tap a few more times. Use a knife or a clean mixing stick to scrape the top and smooth the top surface.

On this second mold, you can see there’s a little prism inside. This will create a void in the top of the finished part, which is good for making this into a planter or candle holder. I added little a bit more water this time so that the concrete could be poured instead of scooped. Again, tap occasionally and just smooth of the top. Now just set the molds aside in a cool dry place for about 12 to 24 hours. You might need to adjust your drying times depending on your concrete mix, the amount of water used, and the ambient temperature and humidity.

It’s the next morning and the pieces are ready to be de-molded. I start by just pulling away the opening. Then I’ll turn the mold upside down so that the concrete can kind of fall out of the mold. It may be a good idea to have something soft underneath so the concrete doesn’t just fall out and get damaged. Then i peel the mold over the concrete with my fingers and kind of push out with my thumbs.

The soft silicone makes it pretty easy to remove these parts. This dodecahedron mold has a void insert that I mentioned earlier. Simply peel back the mold like you did earlier, grab the concrete piece add all it takes is a little wiggle and it should pop right out.

These durable silicone molds can be used to mass produce concrete objects. The silicone gives an incredibly smooth surface finish that will look beautiful and resist chipping and wearing. These silicone molds also work great with candle wax, plaster, chocolate, resin, basically anything you could pour and cure.

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