Maintenance painting with Isotrol Oil Alkyd system for bridges, Viskan, Sweden
The Isotrol Oil Alkyd system is the only system that is accepted by government body of The Swedish Transport Administration in the standards for maintenance of bridges without sand blasting as pre-treatment. Cleaning pre-treatment is usually done by water blasting which cuts the costs considerably and lessens the amount of waste from blasting material and old paint. It is also a great benefit when maintenance is due for objects in remote locations or in environment where spills into nature is liable.
The bridge over the river Viskan is a test object for evaluation of different paint systems on objects that are deemed as heritage. This means the object is considered to have a historical value in addition to the practical usage value.
After 10 years an inspection was made and the system was intact with only smaller rust formations in slots which was expected.
Surfaces were primed with Isotrol Primer to saturate poores and fill crevices and cavities. A intermediary coating of Isoguard Pansar followed before a top coat of Isotrol Finish tinted to the chosen color was applied.
For bridges with many joints, frameworks and rivets the Isotrol Oil Alkyd system often perform better than epoxy systems. This from its superior wetting properties. This has been shown in comparisons in between comparable objects done by The Swedish Transport Administration. They concluded that already after 5 years the Isotrol Oil Alkyd system had fared better than the comparing object painted with epoxy and that the system was intact and needed only smaller spot painting repairs after 24 years.