Knowing how to properly use form release agents and which agent should be used for a particular application can go a long way toward preventing costly mistakes. In addition, following proper procedures and using the right agent can enhance the quality and economy of a finished precast piece.
Make sure the release agent you are using is compatible with the form or mold it is being used on. Some agents react with mold materials to damage the mold or reduce the effect of the agent. Don't purchase a release agent based on price alone. Sometimes the additional money spent on a higher-priced release agent is more than made up in cost savings resulting from fewer spoiled pieces and higher levels of quality.
Know the proper mixing techniques for the agent you choose, and follow the manufacturer's directions for application. Ensure that all workers are adequately trained in all aspects of the application process. Before applying the release agent, make sure the form is clean. Don't allow release agents to contact reinforcing steel. Do not overapply a release agent, especially if that agent is chemically reactive.
There are four types of release agents: oil-based, composed of vegetable oils, paraffin, fatty acids, or similar substances; polymers, which form a coating with anti-stick properties on plywood, metal and other types of forms; VOC-compliant agents, which generally are water-based; and aerosol spray-on release agents.