Iron and metal


Corrosion happens when iron oxidises, which means that when oxygen in the air comes into contact with exposed iron. The presence of salt and water speeds up the process. The rust guard system works by having zinc phosphate (which is more of a base metal than iron) to sacrifice itself before the iron is affected. In other words, the phosphate must not be too firmly anchored to the binding agent as it has to be able to free itself and, in this way, be able to offer itself up.

A tight coat of Effekt Enamel is painted over the sacrificial base-paint Värn Anti-corrosive Primer, in order to prevent the oxygen from coming into contact with the surface metal. If a breach occurs in this tight coat, the base paint’s anode (zinc phosphate) will begin to seep out and offer itself up to any oxygen present instead of the iron.

The base surface must be very well cleaned, steel brushed or sandblasted (Sa 2.5), and any oily patches should be cleaned with a suitable solvent. It is important to prime with rust guard very quickly after cleaning so that the corrosion process cannot begin.


Thin out the first coat of Värn Anti-corrosive Primer with 20% white spirits. Subsequent coats are applied with full strength paint. These coats are then painted over with a covering coat of Effekt Enamel in two coats. This is applied with a brush, roller or spray after diluting with 10-20% white spirits, so that the primer seeps well down into the base surface. The same treatment process also applies for Sköld Sheet roof paint.


Where a breach occurs on a treated surface, steel brush and spot prime once with diluted primer and once undiluted. Then spot coat once with the cover coating (Effekt Enamel), and finally cover the whole surface with the same.

 dark metal roof detail with raindrops