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.