TIPS & TRICKS
Check out our latest video! Here I will be sharing tips and tricks for casting concrete or Cement-All in our newest silicone molds. The tips in this video also apply to anyone interested in silicone molds or casting any material, as most casting processes are very similar.
Mix Cement-All to a ratio of 5:1 CMA to Water to have a flowable concrete mix suitable for smaller objects under 4"
When Pouring concrete into your silicone mold, aim for one side of the mold, pouring in the gap between the wall of and the insert. A steady pour here will allow the concrete to fill up around the rim of the cylinder and up the walls gradually, minimizing potential to trap bubbles and imperfections.
Play with balancing more/less water in your mix to get the ideal combination of more water for flowability and smoothness, but not so much water that you lead to shrinking and cracking.
Concrete cracking during or shortly after curing? You're most likely using too much water, or not enough sand, or both. First try reducing the water used in your mix until you see the cracking cease.
Wear clean rubber gloves when de-molding to avoid getting dirt or hand oils and fingerprints on the raw concrete. Handle the items as little as possible, sanding them soon after they come out of the molds, and sealing them within the next 36 hours. Once the sealer has been applied the surface is locked in and no longer vulnerable to marking, stains, water damage, scratching etc.
Use less water to get a more rustic, industrial, natural, handmade feel. A concrete mixture with less water will be thicker and more clumpy, and when slopped into the mold it is much more likely to trap air bubbles against the surface of the mold. Many modern consumers love proof-of-handmade artifacts that make their wares unique and special. We have found that our imperfect items sell much more often and garner more interest than our perfect items.
Cement-All is fully cured (enough to be removed from the mold) when it is rock hard on top and can't be scratched by a fingernail
Sealing concrete in batches can save time and get you in a rythm of efficient work! In my experiment, it took me just under 6 minutes to seal all 17 concrete planters shown in the video.
This averages out to about 21 seconds per planter in sealing time! This is a good benchmark number for those who want to keep tabs on their production speed and efficiency.
Our Large Cylinder Lid silicone mold does fit this new 4" Cylinder! They are both 4" across.