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:
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If fully coated, oil does a decent job of repelling water on the surface of the metal, thereby preventing rust.
Cons:
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Given time, moisture will diffuse through oil, make contact with the metal surface and cause corrosion or rust.
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Oils are messy and sticky to apply.
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Oils must be removed and the surface cleaned with a solvent or other method.
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Oils are hazardous and disposal may be a problem.
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Oils introduce health risks to workers.
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Oils attract dust and dirt which are not only messy but can lead to corrosion through contamination.

RP Liquids
Pros:
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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:
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Given time, moisture will diffuse through RP liquids and make contact with the metal surface and cause corrosion or rust.
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RPs can be messy and sticky to apply.
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Most RPs must be removed and the surface cleaned with a solvent or other method.
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Many RPs are hazardous and disposal may be a problem.
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Many RPs can introduce health risks to workers.
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Many RPs attract dust and dirt which are not only messy but can lead to corrosion through contamination.
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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:
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Alters the environment to remove moisture and humidity.
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Can work well when applied with a good vapor corrosion inhibitor.
Cons:
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Adsorbs moisture in the air but doesn’t address the surface of the metal.
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Once desiccant pack reaches maximum adsorption it ceases to work.
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Does little to affect other corrosive effects such as gases, contaminants or acidic materials in packaging.
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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:
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Clean, safe, easy to use.
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Combines packaging materials with corrosion inhibitor.
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No messy liquids; leaves returnable packaging and shop environment clean.
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Good VCIs contain no hazardous chemicals to humans or environment.
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Good VCIs have a lasting effect for long term storage yet work quickly to saturate airspace.
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Volatilization of chemical allows VCIs to replenish themselves.
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Ideal for shipping and both short and long term storage.
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Can be used in-process in a production setting.
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Safe on other materials such as plastics, rubber and vinyl.
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Not permanent; allows for flexibility.
Cons:
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May require to be used in combination with other corrosion inhibitors for outside storage.
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Not permanent like a paint.
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Abundance of water infiltration can wash out VCI.
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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.