Poor paint adhesion to galvanized iron

Problem - Poor paint adhesion on galvanized iron
Poor paint adhesion to galvanized iron, or between coats of paint.

Possible causes

  • Poor surface preparation, such as inadequate removal of rust, dirt, or poorly adhered old coats of paint. The surface was cleaned with an unsuitable cleaning agent (i.e. soda, white spirit), or the agent was not rinsed off properly.
  • Old surfaces with too many paint coats.
  • The surface was not undercoated, or was treated with an undercoat unsuitable for galvanized surfaces.
  • The painted surface was damp.
  • The undercoat became too dry before topcoat was applied.
  • The sheet metal has not “aged”.


Remove the loose paint coat by scraping. Sand or use a wire brush to remove rust and white rust. If the paint coat is too thick, remove it entirely.

Clean the surface with Tikkurila Panssaripesu according to instructions on the label. Rinse thoroughly and allow to dry.

Apply a coat of Rostex Super rust inhibitor primer on the clean iron surface, and then a topcoat of Panssarimaali. If you use Repco for topcoating, undercoat with Rostex Super.

Allow it to weather for at least one winter before painting galvanized iron.