Causes

Coating failures/exposure to damp conditions (rusting) The condition of the surface following preparation is a significant factor in the performance of the paint system. Sub-film corrosion is controlled by thorough surface preparation. An effective rust inhibiting primer together with an appropriate finishing system, applied to achieves optimum total dry film thickness.

Solution:

Remove all loose rust and defective coatings by scraping, chipping, wire brushing or abrasion. Feather edges of sound paint with abrasive paper. Remove all dust. Wash with hot water and liquid detergent solution to remove all oil/grease and any other contaminants, frequently changing the water. Rinse thoroughly with clean water and allow to dry. Spot prime all bare metal with one full coat of Crown Trade Zinc Phosphate Primer.