In this blog, we will look closely at the factors to consider while choosing the right shuttering oil, such as types of shuttering oil, and different applications of shuttering oil too.
Concrete is widely used in almost every construction project. It is made by mixing cement, gravel, sand, and water. The cement mix is poured into a mould, to get the desired shape once it dries. On drying, the concrete hardens and retains extensive tensile strength.
The shuttering oil makes it easier to remove moulds after the concrete becomes hard and takes the desired form. This is extremely crucial to build strong foundations, slabs, roofs, high-rise structures, etc.
Shuttering is the process of creating a mould that supports the concrete till it dries. Shuttering oil is also commonly called mould release agent, and formwork oil.
Factors to Check for Choosing the Right Shuttering Oil?
Shuttering oil functions as a lubricant between the mould and concrete in construction projects. It prevents concrete from sticking to the mould till it hardens. Commonly, construction moulds are made from plywood, steel, or aluminum. For this, there are two main types of mould release agents used – Reactive and Barrier.
Ideally, mould release agents should have a stable and long shelf life. The best shuttering oil should enhance the resistance of the mould against damage from excess temperature, or repeated use. Besides this, the shuttering oil should also be free of sediments and contaminants.
In addition, as shuttering oils may contain volatile compounds, they should always be stored in air-tight containers to ensure consistent concentration.
Types of Shuttering Oils
Shuttering oils are available in different types. The specific variety of shuttering oil you will need is based on different construction requirements.
Let’s look at some of the most used shuttering oils –
Neat Oils
Neat oils are mostly mineral-based oils but are likely to develop blowholes on the concrete surface. Hence, neat oils are not usually recommended for use in high-quality concrete constructions. This is why neat oils are mostly applied to moulds and formwork before being stored, or for hidden underground concrete surfaces.
Mould Cream Emulsions
Emulsions of neat oil mixed with water minimize blowholes but can get washed away by rain. They are mostly used for general mould releasing purposes. However, mould cream emulsions are not suitable for use with steel formwork.
Water-Soluble Emulsions
Water-soluble emulsions are rarely used as they produce a visible porous dark film on the concrete surface, which weakens the surface.
Chemical Release Agents
Chemical release agents have small quantities of chemicals dispersed in a low-viscosity oil base. The chemicals react with the cement and produce a soapy compound, which prevents the cement from sticking to the mould once it dries and forms concrete.
Types of Moulds/Formworks
The choice of best shuttering oil also depends on the material of the mould or formwork being used in the construction project.
Here are the various types of moulds and formworks that benefit by using shuttering oils –
Absorbent surfaces
Untreated plywood or timbers are commonly used as moulds in many construction projects. However, these materials tend to absorb the release agent which results in the concrete surface getting a wood-grained pattern.
To prevent this, it is advisable to apply one or multiple coats of normal shuttering oil or use a compatible varnish or barrier paint on the dry surface. It is recommended to apply the right shuttering oil to the mould before it is used.
The brief study on types of shuttering and their comparism that undoubtedly Indian construction has got its wings but on other hand we have to admit the fact that we are still lacking behind in the skilled worker in the field of any other construction method else than on the Plywood.
Non-Absorbent surfaces
When the mould/formwork material is non-absorbent or impervious there is a risk that the shuttering oil can flow and collect at the base. It can also dry up prematurely, especially when an emulsion-based mould release agent is used.
To avoid this, it is recommended to use chemical-based shuttering oil. A single coat of emulsified shuttering agent can be applied close to the pouring time, and prior to every consequent pouring.
Steel surfaces
Chemical-based shuttering oils are highly recommended for use with steel shutters/moulds. When used with quick heating and curing compounds, and de-watering and rust inhibitors, the shuttering oil has significant benefits.
Benefits of Choosing the Right Shuttering Oil
There are major benefits of choosing the right shuttering oil. For instance, it ensures smooth detachment of shuttering or moulds after the concrete has hardened.
Here are the other express benefits of choosing the best shuttering oil –
- Smooth removal of shuttering and moulds
- Minimizes blowholes on concrete surfaces
- Supply suitable surface finish for concrete casts
- Reduces loss of water from concrete due to absorption by timber/plywood moulds
- Lowers seepage of moisture and water during concrete curing process
- Keeps moulds/formwork clean and ready for reuse
- Reduces risk of developing cracks in concrete surfaces by internal adhesion
Tips to Choose the Right Shuttering Oil
According to construction experts, having prior experience working with mould release agent is the best way to choose the right shuttering oil.
Still, another effective way to measure efficiency of different shuttering oil brands is to evaluate them under real-life conditions, or on a test panel. Besides this, you should check the manufacturer’s instructions about the type of mould surface for which the product is intended, and the proper application method.
Here are some more considerations to choosing the right shuttering oil –
Compatibility
Check to make sure that the shuttering oil is compatible with the mould material and sealant.
Final finish goals
If the concrete surface is meant to be plastered or painted, then the mould surface needs to be treated with materials that don’t leave oily or waxy residue.
As this can affect the adhesion of the plaster or paint, care should be always taken. Often, construction experts simply wet the mould surface with water before plastering. The slightly rough surface of the mould tends to make the plaster bond strongly with the base surface.
Durability of surface
Ideally, shuttering oils should not make the concrete surface soft and dusty. It should also have no effect the way watering or curing compounds work.
Staining and Discoloration
It is highly recommended to use completely non-staining shuttering oils, regardless of the type of finish desired on the concrete surface. This will prevent uneven coloring in the concrete.
Apart from this, the other factors to consider for the right shuttering oil are the duration required before stripping the mould, the environment of the concrete cast, and the uniformity of mould release agent.
Conclusion
It is crucial to choose the right shuttering oil to ensure the several benefits expected from a construction project. When you buy the best shuttering oil, you ensure that de-moulding becomes easier.
It reduces the risks of developing blowholes in the final finish surface by minimizing loss of water and moisture during the curing process. The mould release agent also keeps moulds and formworks clean and ready for re-use.