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 its 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.

 

 

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.

 

 

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.

 

 

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.

 

If you’re experiencing corrosion problems, contact an ARMOR corrosion specialist to schedule a visit for a corrosion audit.

 

© 2016 Accuratech Machine Industries. Official distributor of Armor VCI products in the Philippines.