Seal n Peel Solutions: Rust Colour Indicates the Cause

seal n peel

You can nip rust even before it forms by using seal n peel protective coating solution such as Unituff 452 and Unituff OGS for stainless steel.

But did you know that the colour of rust is indicative of its cause?

Yellow Rust

Iron oxide-hydroxide caused by high moisture levels, or overexposure to rainy conditions. Also called solvated rust, it is usually found in recessed areas of metal parts or equipment where the rust is “runny” or “dripping.” High moisture content may also indicate puddled or standing water.

Brown Rust

Indicative of high oxygen but low moisture levels. Brown rust appears as a reddish-brown crust on metal surfaces as a result of water and oxygen in the atmosphere. Brown rust can also appear only in localised areas rather than on surfaces that resulted from contaminants from the manufacturing process.

Red Rust

Hydrated oxide due to high oxygen and water exposure. Red rust can also form when another contaminates such as salt is mixed in. This type of rust is uniformed corrosion, so there are no signs of rust streaks. Red rust is indicative of a very corrosive environment such as areas near or at sea.

Black Rust

Iron oxide as a result of limited oxygen and low moisture. It is a thin, black film or appears like a black stain. Most likely, areas that have black rust had something covering them that prevented oxygen from reaching the surface. Unlike other rust forms, it does not propagate outside its territory.

Aside from the causes indicated above, rust may also start because of the following human errors:

  • Handling metal parts without gloves (hands can transfer salt and moisture).
  • Packaging metal parts in direct contact with corrugated boxes, pallets, and wooden crates.
  • Leaving metal parts uncovered and unprotected on the floor.
  • Storing metal parts in areas with extreme heat.
  • Not completely drying out metal parts after cleaning solutions are used on them.
  • Not keeping metalworking fluids clean.
  • Not using de-ionised or distilled water in cleaning fluids and metalworking fluids.
  • Using improper pH level in washwater and metalworking fluids.
  • Not monitoring atmospheric conditions where metals are stored.
  • Not using anti-rust protective coatings.

Rather than having a battle with rust when it has already gotten hold of metal, the best solution is to stop rust even before it starts forming. This can only be done if you use a flexible polyvinyl chloride copolymer solution protective coating around the metal such as Unituff 452 (formerly Seal’n’Peel). The externally applied heavy-duty protective membrane prevents moisture from creeping into the metal, stopping the start of rust, and even stops rust creep.

Unituff 452 works on all types of metal (Unituff OGS is specially made for stainless steel) because some metals are more susceptible to corrosion than others. The coating even covers gaps in metal parts so no rust can form. The seal n peel coating is a protective covering that stops all temperature, humidity, and contaminants from penetrating to the metal. To learn more about how Unituff products can work wonders with metals in your industry, visit the website at