Casting Cement With a Silicone Mold.

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Introduction: Casting Cement With a Silicone Mold.

About: Artist and teacher

Casting with cement can be fun and easy if you into the process with the right attitude. I started using epoxy resin about a year ago with silicone molds so using cement is a lot cheaper. For what I paid for resin I could get more than quadruple the amount of material out of cement. So if you're cheap like me, but like to experiment cement is a really good option.

Step 1: Step 1: the Mold

You can use many different kinds of silicone molds. A great place to scope out molds in the bakery or confectionery section of your local craft store. A lot of my favorite molds are silicone ice cube trays.

For this instructable i'll use on of my own original mold that I made with SmoothOn's oomoo 30.

Step 2: Mixing Your Cement

I like to use plain Portland cement or mortar for my final piece. I find that using concrete can be a challenge for smaller pieces because the aggregate in the concrete can settle in the mix and ruin some of your detail.

For Portland Cement I use a 1 to 1 ratio cement to water. When you mix them together they should be the consistency of oatmeal.

Step 3: Pouring the Cement

When you pour the cement you should do it slowly, bit by bit into your mold. It's a little chunky and you'll clog up the opening to your mold if you do it too fast.

While you are pouring you should be vibrating your mold to allow the bubbles to escape and for the cement to fill in the open spaces. You don't need a specific tool for this, some people will run a sander on the table. I like to tap my mold on the side. If you have any overhangs you may want to pick up the mold and wiggle it around to make sure your mix is everywhere.

Step 4: A Lot of Detail

You can get a surprising amount of detail in the cement. It really takes patience and experimentation. You might want to experiment with sand and aggregate to get a certain texture you're looking for.

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    7 Comments

    0
    chloeelizabeth140198
    chloeelizabeth140198

    Question 7 months ago

    I'm getting a white residue left in my mold and on my concrete that I cannot remove. Should I be using a lubricant on thr silicone to prevent this?

    0
    perpetualenigmamom
    perpetualenigmamom

    Question 7 months ago on Step 1

    Do you need to use a non-stick agent on the mold before pouring in the concrete or will it release with ease when the concrete is dry?

    0
    davelamorte
    davelamorte

    Answer 7 months ago

    I use a spray lubricant from smooth on.

    0
    upcyclemaniabygin
    upcyclemaniabygin

    12 months ago

    I love this!
    Can you reuse the mold? (If it's a silicone ice cube tray)

    0
    davelamorte
    davelamorte

    Reply 11 months ago

    They last only a few years. The repeated use will degrade/dry out the molds.

    1
    Penolopy Bulnick
    Penolopy Bulnick

    2 years ago

    I love your little skull mushroom :)

    0
    davelamorte
    davelamorte

    Reply 2 years ago

    Thanks! They were for a video game convention.