We mainly use two different paint systems depending on the wall material i.e. render, stone, granite.
In 1982/83 Trinity House started a Grit Blasting program to remove all old paint coatings from the wall elevations and apply a two part polyurethane system, a gloss finish.
This is a very hard coating and gives a six to eight year period before recoating is required. The joinery of the station is re painted every three to four years with oil based undercoat and gloss.
The polyurethane system is also used on the station metal work.
In the last ten years, on grit blasted render stations, we have been applying a more flexible coating, Monolastex Smooth which is water based coating. The coating gives water vapour permeability, tolerates thermal movements in the substrate, and contains an active fungistatic system which prevents the growth of mould, fungus and algae on the paint surface. This system provides a matt finish.
We have found the system user friendly and easy to apply. It is certified as a two coat application plus a priming coat which lasts for 15 years but in our exposed environment we recoat our stations every six to eight years.
We have had problems with offshore lighthouses which are damp and have little or no heating.
After carrying out paint trials with a number of products we found a liquid plastics product which has preformed well when used in our off shore buildings. It is vapour permeable and is a fungicidal system. It is highly elastic so tolerates structural movement.