SIKA Release agent D

Sika Release agent D is a water-based release oil designed to prevent concrete and mortar from adhering to all types of formwork and moulds. Emulsified in water at variable ratios, it works on both absorbent formwork and non-porous surfaces, and is equally effective as a separation agent between mould materials such as silicone and polyurethane. Regular use extends mould life and facilitates demoulding without damaging surfaces.

Technical specifications

What it is used for

Release agent D is designed for applications where a clean separation is needed between the mould or formwork and the poured material. Its water-emulsifiable formulation makes it especially versatile in the workshop and on site. It is used in the following combinations and contexts:

• Wood or wood-based formwork for concrete and mortar
• Metal formwork in precast concrete
• Separation between polyurethane rubber and the original model
• Separation between polyurethane resin and polyurethane rubber mould
• Separation between silicone and the original model
• Separation between silicone and silicone (mould over counter-mould)
• Separation between polyurethane resin and silicone mould
• Series production where extended mould life is required

How to use it

1. Make sure the formwork or mould surface is completely clean and dry before applying.
2. Shake or thoroughly mix the product before use, especially if it has been stored or previously diluted.
3. If diluting, mix Release agent D with water at the appropriate ratio according to the type of formwork and the absorption level of the material.
4. Apply a uniform coat with a brush over the entire contact surface. Avoid build-up or puddles.
5. Allow a few minutes for the oil to form a continuous film before pouring concrete, mortar, or mould material.
6. Repeat the application between each casting cycle to maintain release effectiveness and protect the formwork.

Usage tips

Dilution and concentration

The dilution ratio in water depends on the substrate. On absorbent formwork such as wood, a more concentrated emulsion ensures a sufficient protective film. On metal or plastic surfaces, a higher dilution is common. Run tests on a small section first if working with new formwork or an unfamiliar material.

Compatibility with silicone and polyurethane moulds

When working with silicone or polyurethane rubber moulds, Release agent D acts as a barrier between layers. It is especially useful when making counter-moulds or duplicating an existing mould. Make sure to cover edges and detail areas thoroughly, as these are the points where most adhesion problems occur. If you need a general-purpose workshop release agent, the Ease-Demold 305 is a very convenient spray alternative for complex geometry parts.

Maintenance and storage

Always homogenise the product before each use, especially if some time has passed since the last application. Store in a cool, dry place away from heat sources. If you have prepared a diluted emulsion, use it the same day or store it in a sealed container to prevent the aqueous phase from separating.

Frequently asked questions