Symptom

Damage of aluminium by filiform corrosion.

Cause

• Porous paint layers
• Insufficient dry film thickness
• Environmental influences
• Untreated window recess
• Insufficient periodic cleaning
• Sharp edges

Solution

Any unsound coating should be removed. Remove oxides and salts from the substrate by sanding it with a [Scotch Brite pad]. Degrease. Touch up any bare patches  with [Redox EP Metal Primer]. Apply two complete coats of [Redox PUR Finish Gloss].

In general, if oxidation is visible, then sufficient preparation or pre-treatment may not have been carried out effectively during the initial decoration. If this is the case, only a limited service can be expected from subsequent paint systems. On average a limited service life can be expected because the pretreatment could not be carried properly and the construction is such that it can not sufficiently be protected with a paint system.