Release agent & impregnating agent for moulding & casting sculptures & objects

Before choosing the release agent: What exactly do you want to mould and cast and with what?

The decision for one or more release agents is made when it is clear which object you want to mould with which impression material and which material you will use to produce the cast. The following is important for the choice of release agent:

- What is the original model, the object that is to be moulded, made of?- What surface texture does the original model have? Is it coloured?- is the original model particularly valuable and must therefore be treated particularly carefully?
- which moulding compound do you want to use for moulding?
- Which casting compound do you want to use to make the cast?
You will choose the release agents and, if necessary, an impregnation accordingly. In principle,the master model,moulding material and casting material should fit together . Of course, the aim is also to ensure that the master model is not damaged during the moulding process.

We generally recommend that you first test the release agent or impregnating agent on an inconspicuous area, e.g. on the back or underside of the original model, before applying it to a large area.Test on an inconspicuous area, e.g. on the back or underside of the original model, to ensure that there are no undesirable reactions with the surface. It is not always possible to determine the exact nature of an object simply by looking at it.

What types of release agents are there?

Release agents and impregnating agents can be characterised in different ways with regard to certain functions.

For example, there are water-based release agents, solvent-based release agents and oil-based release agentsl – some release agents also fall into several categories. Not every release agent is therefore suitable for every substrate or for every moulding or casting compound. The components usually also determine whether and how well the release agent can be removed again or whether it remains as a permanent protective layer, for example.

Release agents also differ in terms ofhow they are applied: e.g. with a cloth, brush and brush or as a spray. Some release agents need to beheated first before they can be applied.

If you have an original model with a detailed surface, we recommend using a release agent, for example, which is sprayed on very finely so that no detail is lost.

However, if a surface that is to be moulded is porous, has cracks or a rough structure, pretreatment with a supporting, filling or levelling agent may be useful, if not necessary.

When does my master model or object that I want to mould require pre-treatment or impregnation?

Some original objects require pre-treatment or impregnation before they are allowed to come into contact with a release agent or the impression material. The aim of pre-treatment is to seal the surface of the original object  and protect it, i.e. to provide it with an impregnation so that neither the release agent nor the moulding compound can penetrate the surface and adhere or damage the object. The original object should look exactly the same after moulding as before!
Basically, two types of agents can be distinguished for sealing surfaces: There are agents that are water-soluble and can be washed off again, and agents that remain on the object but are virtually invisible. This can be a permanent protection for the object, even against normal environmental influences.

For valuable and/or delicate original objects it is important to consider very carefully what is "reasonable" for the object. Can it be washed off without any problems? Does it change the object if it is coated with a thin layer of wax or another transparent film, even if it is barely visible or not visible at all? Does the release agent or impregnating agent contain a solvent that could attack the surface of my original model? Or does the impregnating agent react with the surface of my object in some other way?
Pre-treatment is recommended, for example for raw, unpainted wood, especially if it has cracks, for objects made of unpainted plywood or pressboard, for objects made of unglazed ceramic, cement, concrete, plaster or stone, generally for all absorbent materials or materials with an open structure (e.g. Ytong, brick, sandstone, etc.).e.g. Ytong, brick, sandstone, etc.). Pre-treatment can also be useful for original objects that are painted withwater-soluble colours or with colours that are not solvent-resistant.

If an object has cracks or an uneven or rough surface, pre-treatment is also advisable, as the moulding compound can otherwise settle in the cavities and the solidified mould cannot be easily removed. Cracks in wood must therefore be filled, a surface with many air bubbles may need to be levelled out. This may mean that the mould can be removed from some objects, but not the original surface structure.

Pre-treatment is generally not required for objects made of solid, smooth materials such as glass, porcelain, glazed ceramic, metal and plastic or for painted objects. When moulding with silicone without a release agent, however, a metal surface, for example, can also oxidise. In this case, a release wax is recommended as an impregnation. In many cases, the impregnation then also serves as a release agent.

Which products are suitable for pre-treatment or impregnation?

At this point, we will only mention a few products that can be used for the pre-treatment of master models. Further information can be found under the respective products!
PVA (polyvinyl alcohol): Seals open-pored surfaces such as plaster and wood; is water-soluble and can be easily washed off objects that tolerate water. If the surface structure of the object is very porous, the PVA layer can be removed by sanding if necessary. PVA is not necessarily suitable if another release agent or a water-based moulding compound is to be used, as the agent could be dissolved during the working process.
Water-based varnish: A matt water-based varnish can protect untreated or coloured wood surfaces, for example. Water or release agents and water-based moulding compounds can then no longer penetrate.

Release soap: can be used, for example, to smooth out cracks or a very rough surface; is water-soluble and therefore washable from objects that cannot be damaged by water.

Release wax: can also be used very well to level out cracks or rough surfaces; also makes the surface insensitive to water. Accordingly, release wax can only be removed to a limited extent – e.g. with hot water or suitable solvents, provided the original model allows such treatment. On the other hand, release wax can also offer longer-term protection.

Moulding: Which release agent do I use for which materials?

Plaster from plaster: To separate plaster from plaster, you can use a wide variety of very simple release agents, such as washing-up liquid, soap, Vaseline or clay slurry (clay dissolved in water).
Making silicone casting moulds: Almost all release agents offered by bildhau are suitable for separating the master model and silicone, if a release agent is required at all, depending on the nature of the master model (pre-treatment may be necessary, see section above). Please note that a release agent containing oil or grease (e.g. Vaseline, demoulding grease, silicone mould release agent creamy) can impair the curing properties of two-component silicone and should therefore not be used in this case. If you want to mould a metal object with silicone, we recommend using a release agent such as release wax, as the metal can oxidise on direct contact with the silicone. Undried clay, plasticine and wax as master models generally do not require a release agent when making silicone moulds.
Silicone from silicone: If you are working with multi-part silicone moulds, they must be separated from each other during production. You will need a release agent such as Universal Release Agent Wax Z 25, PST-4 or ARTIDEE Silicone Mould Release Cream. Please also note here that a release agent containing oil or grease (e.g. Vaseline, demoulding grease, silicone mould release agent creamy) can impair the curing properties of two-component silicone.

Making casting moulds from synthetic resins (polyester, polyurethane, epoxy): For the production of casting moulds from synthetic resins, PVA, universal release wax Z 25, PST-4 or the ARTIDEE mould release agent, for example, are suitable for separating from the master model.

Further information on the functions of the individual release agents can be found with the respective products!

Moulding: Which release agent do I use for which materials?

If you want to make a cast in a mould made before you, the choice of release agent depends on what your mould is made of and which casting compound you want to use to make the cast:

Silicone moulds: If a silicone mould is to be filled with cement or concrete, a greasy release agent is required, especially to protect the mould from the aggressive casting compound. When plaster casting in a silicone mould, a release agent is not usually necessary, but can be helpful for easier demoulding of more complicated moulds (e.g. ARTIDEE mould release spray). For casting with synthetic resins (polyester, polyurethane, epoxy) in a silicone mould, you can use PVA or ARTIDEE mould release agent, for example.

Synthetic resin moulds (polyurethane, polyester and epoxy with glass fibre): Synthetic resin moulds can in principle be cast with all casting compounds, only casting with liquid clay is not recommended as the water cannot escape from the clay– plaster moulds are much more suitable here. PVA or the ARTIDEE mould release agent, for example, is suitable as a release agent. If you use PVA as a release agent, please always ensure that you apply the PVA in several layers and that each layer is completely dry before adding the next layer.PU moulds, but also other plastic moulds, can be processed very well with release wax (e.g. ARTIDEE release agent wax) or other release agents containing wax (e.g. Universell Trennwachs Z 25 or PST-4). If you mould filigree objects, please ensure that the wax layer is not too thick – this can obscure details.

Latex moulds: Can be used for almost all casting compounds: No release agent is required for ceramic casting compounds, plaster and cement. However, depending on the design of the mould, release agents can facilitate demoulding, e.g. ARTIDEE release agent wax, ARTIDEE silicone release spray, ARTIDEE mould release agent cement and concrete can attack the latex. If you are planning several casts, a greasy release agent is recommended to protect the latex mould. Synthetic resins also attack the natural latex product. A release agent is required here to protect the mouldn, e.g. ARTIDEE Mould Release Agent or ARTIDEE Silicone Release Spray if you want to cast with polyester or polyurethane. To prevent latex moulds from sticking together, it is best to rub them with talcum powder.
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There are many different combinations of moulds and casting compounds. We can only list a few possibilities for the use of release agents here. Therefore, please also refer to the individual product pages or contact us if you have any questions about your specific project!