Because the water on the surface of the wet concrete will prevent the mold release agent from adhering properly, resulting in an ineffective barrier. It may lead to poor mold release and potentially damage the concrete mold. Moreover, the moisture can also dilute the mold release agent, reducing its effectiveness.
Best Practices for Using Mold Release Agents on Wet Concrete Molds:
While direct application on wet concrete molds is not advised, there are certain best practices you can follow to achieve optimal results when using a mold release agent on wet concrete molds.
1. Allow Proper Drying Time:
Before applying the mold release agent, ensure that the wet concrete mold has had sufficient time to dry. Ideally, the mold should be completely dry to the touch, with all visible water evaporated.
2. Apply Mold Release Agent Indirectly:
To ensure proper adhesion of the mold release agent, apply it indirectly by first spraying or applying it onto a cloth or sponge. Then, gently coat the surface of the concrete mold with the cloth or sponge, ensuring a thin and even layer.
3. Use a Dry Release Agent:
Another option is to use a dry release agent, which eliminates the need for a liquid or paste formulation. Dry release agents typically consist of fine powders, such as talc or powdered wax. These powders are sprinkled onto the wet concrete mold and spread evenly, providing an effective barrier between the mold and the uncured concrete.
4. Consider Pre-Treating the Mold:
In some cases, pre-treating the mold before pouring wet concrete can help prevent sticking. This can be done by lightly coating the mold with a mold release agent and allowing it to dry before pouring the concrete.
Applying a mold release agent directly on a wet concrete mold is not recommended due to poor adhesion and potential damage to the mold. However, by following the best practices outlined above, you can effectively use a mold release agent on wet concrete molds. Remember to allow proper drying time, apply the agent indirectly, consider using a dry release agent, and optionally pre-treat the mold before pouring wet concrete. These practices will contribute to successful mold release and help achieve clean and undamaged concrete products.