Whirrrrrrrrrrrrrrrr click click click the answer is iron phosphate and polyester powder coating. Zinc phosphate can increase that to between 500 and 1 000 hours.
Let s see what the answer is by spinning the wheel.
Powder coating salt spray life. For example hot dip galvanizing can last 75 100 years with no maintenance no other finish comes close but it performs rather poorly in salt spray tests because its real world endurance depends on the slow formation over months and years of a glassy stable skin of corrosion product compounds like zinc carbonates which don t form in the salt spray chamber. The surface that the powder is applied to is not clean enough or lacks a sufficient conversion coating. For example iron phosphate on steel with a single coat of powder will usually provide around 250 to 500 hours of salt spray resistance.
There are many examples of relative salt spray test results such as. A primer coat and topcoat combination can give you well over 1 000 hours of salt spray. We spin the wheel and see what coating to use on our product that requires 500 hours salt spray corrosion resistance on a steel substrate.
Black oxide samples demonstrates corrosion after 24 to 96 hours ruspert coating 200 300 samples have no traces of red rust after 1000 hours powder coating samples may last for 500 hours before rusting is observed.