Unlike wax and cedar, concrete doesn’t often stick to molds, but this doesn’t indicate that it wo not do this, particularly if the concrete is an aggregate mix or the mold is brand new. Preventing it from sticking means your designs will probably turn out with complete detail and no damage, and the molds will last longer.

Release Agent

Coat the mold with a release agent to prevent concrete from sticking. The release agent forms a thin film that lubricates the mold so the concrete will slip right out after it’s dried. You can purchase a release agent made specifically for concrete molds, or make your own by mixing 1 part castor oil with 8 parts denatured alcohol. Shake the mixture well before spraying the mold. Apply a light coat to the mold, ensuring that the release agent doesn’t pool at the bottom, and pour the concrete instantly. If the release agent accumulates at the bottom of the mold, then wipe it out and begin again. An excessive amount of release agent or allowing it to collect in the bottom can create small voids in the surface of your concrete and eliminate small details meant to be imparted from the mold.

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