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Rust is like disease that hampers the daily cycle of industry work & imposes a long-term adverse effect on industry. To eliminate industrial rust, let's understand the basics.

Castrol’s 101 on Industrial Rust Prevention

Automotive Industry produces a large volume of components to meet this ever-growing demand for mobility. It is a delight to see freshly machined components with precise surface finish shining across the shop floor. The same aesthetics is desired by the customers as well when they receive these parts for assembly. However, rust plays a hurdle not just to aesthetics but also results in component rejection, costing monetary loss.


Rust is like a disease that can hamper the daily cycle of industry work and impose a long-term adverse effect on the particular industry. To eliminate rust, let us understand the basics first.

  • Rust is an undesirable change that occurs because of the reaction between metal components & the gases present in the atmosphere.
  • Moisture & acidic fumes aggravate the rusting mechanism. When Ferrous comes in contact with moisture, it turns into ferric oxide, commonly called rust in our industry.
  • The change is irreversible as we can only scrape off the rusted metal surface.                  
  • This means there will be a loss of metallurgy, leading to a change in surface finish.


Few factors that accelerate the rate of rusting are as follows:


  • Moist conditions in the shopfloor or high humidity climate
  • Presence of dissolved salt in the moisture, especially in coastal areas.
  • Presence of acid fumes in the shopfloor or atmosphere.   

Preventing rust is an important aspect you should consider. It can save you a lot of time and money. It is always suggested to figure out the root cause of rust and then deal with it. There are various ways to prevent rust.

This article will guide you about rust prevention of machined components by application of rust preventive oils.


Which is the most effective Rust Preventive Measure?


Rust preventive oils are the most widely used medium to protect machined components during ‘In house storage’ & ‘In Transit’. The oily or dry anti-rust film over the metal surface facilitates water displacement and isolates oxygen. Therefore, the absence of moisture and oxygen prevents rust.

  • A well-selected rust preventive oil firstly eliminates the moisture from the surface. It forms a barrier film on the component, which can be either waxy or oily depending on your customer’s requirement.         
  • This barrier protects the components throughout the journey and until it is assembled.     
  • Hence, this protective oil film must be intact throughout the desired protection period of the component.      
  • At the same time, the rust preventive oil film should be easily degreasable/washable if required before assembly.   


What Are the Advantages of Rust Preventive Oils?


These are few advantages we can expect while using an optimum rust preventive.

  • Water displacement
  • Film retention
  • Fingerprint suppression  
  • Acid fume protection
  • Temperature stability
  • Fluid compatibility with engine oils & transmissions oils


Criteria to Consider Before Choosing Rust Preventive Oil?


  • Environmental Effect: Study the consequences on the environment that the oil will have after its application.
  • Fluid Consumption: Understand the consumption rate of the oil so that it proves to be economical.
  • Wastage: The oil should not generate much wastage so that frequent changeover is needed.
  • Product Maintenance: The product should be low on maintenance so that it is economical.
  • Operational Cost: The product should not incur any high operation costs.
  • Quality Parameters: The product should comply with the quality parameters like water displacement, film retention, acid fume protection, temperature stability, fingerprint suppression, and fluid compatibility with engine oils.
  • Safety Compliance: There should not be any safety breach by these products. It should emit low VOCs and comply with all safety norms.


Specific advantages of Castrol’s Rust Preventive oils.


  • The product is non-staining.
  • Due to its high coverage, the application is economical.
  • It creates an unbreakable strong film.
  • It has good water isolation properties.
  • Low residue, and thus, there aren’t any deposits on metallic components.
  • It’s operator-friendly.
  • Easy to apply by brush, swab, or spray.


Rust Preventive oil’s working methodology


  • Any rust preventive oil has to execute these three actions for effective rust protection. Dewatering, Film formation & Chemical Action. But the efficiency in each of these actions is the key. Yes, most of the rust preventive oils in the market have a Dewatering feature, but quick dewatering ensures maximum moisture removal within minimum dipping time. Dewatered moisture should also be quickly demulsified, allowing it to settle at the bottom. This makes water removal from the tank bottom easy & also the filtration effective.
  • Once Dewatering is done, the formation of a protective film is very important. This can be achieved when the excess oil quickly dries away from the surface & a thin film is quickly formed covering the component. This film should be easily degreasable at your customer end post receipt. We have rust preventive oils which leave a film lesser than 1 micron of film thickness. This is also known in the industry as the ‘Dry to touch’ range of products.
  • Once the film is formed, Castrol’s Rustilo is enriched with Polar additives which repel the moisture & also are capable of neutralizing acidic fumes. Our oils also have a fingerprint neutralizer that can prevent rusting even if an operator unintentionally touches the component after the rust preventive oil application.


What Are the Checkpoints of the Application of Rust Preventive (RP) Oils?


  • The component surface should be free from any previous process fluid before RP oil application.        
  • 3 Ds’ -Dipping, Draining & Drying should be followed religiously. Dipping for a minimum of 45 seconds, draining for 30 Seconds, and Drying the components for 45 minutes before packing is a successful technique adopted worldwide to ensure effective dewatering & minimum oil on the component.
  • There should not be any rust or residue after the application.
  • It should be translucent in appearance.
  • Water content should not be high.
  • No polluting substance is present after the application or within the oil.

Castrol’s On-Site Testing


Castrol provides on-site expertise for your guidance on rust preventives: 

  • Castrol provides condition inspection and trend analysis. It helps in proactive maintenance to leverage product performance.
  • Provides on-site test kits for immediate critical checks.
  • Well-trained executives for executing filtration roosters.
  • Global team support.
  • Expertise in the lube industry.

Rust efficacy test is one such on-site testing method.




Castrol provides a liquid engineering solution to all your rust problems. The dedicated team of Castrol provides you with high-end solutions and training programs.

Rustilo by Castrol is a solid defense against rust. The process by which Rustilo works is in three steps: dewatering, film formation, and chemical action.

  • Dewatering includes quick dewatering, quick demulsification, and easy filtration.
  • Film formation includes a quick-drying process, thin-film formation, and no grease as residue.
  • Chemical action includes polar additives, fingerprint neutralizers, and acid neutralizers.


The three primary advantages of Rustilo are:


  • Eradicates previous process fluids.
  • It quickly repels water.
  • It leaves a negligible amount of residue.

Rustilo has a wide range of products that are categorically divided as follows:



Smell-free rust preventive:

  • Rustilo DW 300 X
  • Rustilo DW 310

High-flash point rust preventive:

  • Rustilo DW 250 HF
  • Rustilo DW 270 HF
  • Rustilo 630
  • Rustilo DW 205

Waxy film rust preventive:

  • Rustilo DWX 30
  • Rustilo DWX 32 VAL
  • Rustilo DWX 32
  • Rustilo 401 CR

Oily film rust preventive:

  • Rustilo DW 902
  • Rustilo DW 901
  • Rustilo DW 904

Dewatering solvent:

  • Rustilo DW 950


Rustilo is one of the best rust preventive products available in the market. Rustilo comes from the house of Castrol, one of the leading lubricant manufacturers in India.


With Rustilo, you will have the best on-site support team. The technical experts of Castrol have decades of experience and are competent to find solutions to complex technical challenges.


Castrol also excels in conducting on-site training programs for loyal customers to share and impart best industrial practices and product USPs to optimize operating costs. You will be part of this knowledge sharing wherever you may be.


Explore the high-value products of Castrol.