Method comparison chart

Other Methods

There have been many methods used over the years to try and prevent corrosion. These methods include dehumidification, evacuation of air/gases, nitrogen purges and protective barrier coatings. Each method has it’s pros and cons.


Oils

Pros:

  • If fully coated, oil does a decent job of repelling water on the surface of the metal, thereby preventing rust.

Cons:

  • Given time, moisture will diffuse through oil, make contact with the metal surface and cause corrosion or rust.
  • Oils are messy and sticky to apply.
  • Oils must be removed and the surface cleaned with a solvent or other method.
  • Oils are hazardous and disposal may be a problem.
  • Oils introduce health risks to workers.
  • Oils attract dust and dirt which are not only messy but can lead to corrosion through contamination.
Oil rust prevention

RP Liquids

Pros:

  • If fully coated, a good RP liquid can do a decent job of repelling water on the surface of the metal, thereby preventing rust.

Cons:

  • Given time, moisture will diffuse through RP liquids and make contact with the metal surface and cause corrosion or rust.
  • RPs can be messy and sticky to apply.
  • Most RPs must be removed and the surface cleaned with a solvent or other method.
  • Many RPs are hazardous and disposal may be a problem.
  • Many RPs can introduce health risks to workers.
  • Many RPs attract dust and dirt which are not only messy but can lead to corrosion through contamination.
  • If you are mixing the RP, ratios and proper mixing methods are important and mistakes can lead to rust issues if not caught.
Liquid rust prevention

Paints

Pros:

  • If a product is able to be painted, this should provide the best method of corrosion prevention.
  • A paint is visible on the surface providing assurance that a metal parts has been coated.

Cons:

  • It is typically not practical or feasible to paint a metal part that is used in engines, transmissions, electronics, or other critical applications.
  • Paints are messy to apply.
  • Paints are permanent and not likely to be removed.
  • Paints can introduce health risks to workers.
Man painting metal piece

Desiccants

Pros:

  • Alters the environment to remove moisture and humidity.
  • Can work well when applied with a good vapor corrosion inhibitor.

Cons:

  • Adsorbs moisture in the air but doesn’t address the surface of the metal.
  • Once desiccant pack reaches maximum adsorption it ceases to work.
  • Does little to affect other corrosive effects such as gases, contaminants or acidic materials in packaging.
  • In large packaging scenarios, it is not practical to rely soley on desiccants to desiccate an area; must be used in combination with other materials.
Desiccants

Vapor Corrosion Inhibitors

Pros:

  • Clean, safe, easy to use.
  • Combines packaging materials with corrosion inhibitor.
  • No messy liquids; leaves returnable packaging and shop environment clean.
  • Good VCIs contain no hazardous chemicals to humans or environment.
  • Good VCIs have a lasting effect for long term storage yet work quickly to saturate airspace.
  • Volatilization of chemical allows VCIs to replenish themselves.
  • Ideal for shipping and both short and long term storage.
  • Can be used in-process in a production setting.
  • Safe on other materials such as plastics, rubber and vinyl.
  • Not permanent; allows for flexibility.

Cons:

  • May require to be used in combination with other corrosion inhibitors for outside storage.
  • Not permanent like a paint.
  • Abundance of water infiltration can wash out VCI.
  • If rust is already present, may not work as well as an oil in masking a problem.
Armor paper

For further information about the benefits of ARMOR vapor corrosion inhibitor (VCI) nanotechnology, explore the other parts of the ARMOR website!