Uses: Release agents are used in making moulds as well as for making reproductions (moulded pieces). They prevent the different materials from sticking to one another.
Despite the fact that silicone is self-releasing, we still recommend that when making moulded pieces using siliconemoulds you always employ a release agent in order to avoid a malfunctioning of the inhibitors involved in the chemical reaction and to prevent any adhesive imparting substances that may form on the master form from forming a bond that is very difficult to undo. In addition, such things as glass, glazed surfaces or enamel should always be treated with release agent because the silicone rubber sticks more readily to these materials.
Master forms made out of porous materials (wood, gypsum, clay, natural stone, cement, etc.) must always be treated with a pore-sealing release agent in order to prevent the moulding material from penetrating the master form with the result that it will be stuck to it or will discolour. Examples of a pore-sealing release agent include methylcellulose (wallpaper glue) or a soap and water solution.
When making (large) silicone moulds in several steps, after the first stage has been poured it too must likewise be treated with a release agent after it has cured because the poured material of the second stage will otherwise stick to the fresh silicone rubber from the first stage even though it has cured.
When making reproductions using silicone moulds, a release agent is not really necessary because of the self-releasing attribute of the silicone rubber (with the exception of epoxy resins). Moulds that are not self-releasing (polyurethane, latex, gypsum, etc.) must definitely be treated with a release agent. If you are working with a material that will require subsequent painting, you must take care that the release agent will take to being painted because at the time of de-moulding traces of the release agent can remain stuck to the moulded piece. There is also the option that you can thoroughly clean the cast object and that way remove any remaining release agent traces before painting it. For this method, cleaning solvent or turpentine can be used.
The following can be used as release agents: low viscosity or pasty wax dispersion, silicone oil (release agent spray, silicone spray), polyvinyl alcohol, sulphur-free vaseline (pharmacy quality) either as is or mixed into a cleaning solvent solution, and many more.
Safety at work: Release agents are inflammable and hazardous to your health and the environment. The fumes can cause drowsiness and light-headedness which means that release agents should only be used in well ventilated spaces. Direct contact with skin and eyes should definitely be avoided by means of, for example, chemical resistant gloves and safety glasses. A barrier cream is recommended for the cleaning and care of your skin. Beyond that, release agents are hazardous to water and must not be allowed to enter into the plumbing, bodies of water or the soil.
Please take note of the dangers and safety tips found on the packaging. We will be glad to send you safety data sheets upon request.
Which release agent? To the question “which release agent should be used for which purpose?”, there is a parting of the ways. The determination can be based on the following aspects: when making a mould, the master form, which could possibly be valuable, should not be negatively effected by the release agent. Where necessary, an inconspicuous spot must be found for determining whether the agent can be removed without leaving any trace. When making silicone moulds in multiple steps or when casting with silicone, neither silicone oil nor silicone spray should be used - a pasty wax is the right material for the job. Release agents that contain silicone are difficult to remove. When making reproductions, you should therefore not use this type of agent if you plan on painting the moulded piece as the final step.