Before doing any work on a metal surface it must be free from corrosion
, and it is essential to remove salt
and contamination by high pressure (minimum 2500 psi) freshwater washing
I always prefer to use coating systems* from a single
manufacturer (*including cleaners, primers, & overcoats), and follow all directions meticulously.
Assuming the existing coating is sound and intact
, and that you are overcoating with the same antifouling:
1. Wash the surface with soap and freshwater, remove any loose paint
and allow to dry.
2. Apply two new coats of antifouling.
FAIRING, PRIMING, & ANTI_FOULING:
For areas where the coatings are damaged
, filling, fairing, and priming may be necessary before application of primer and antifouling.
1. Shot blast or abrade (100-240 grade abrasive paper) to bright metal.
2. Remove dust and grit by brushing, vacuuming or using dry compressed air.
3. Wash with soap and freshwater.
4. Allow to dry.
5. Spot prime and fill where necessary using appropriate materials. I recommend about four coats of epoxy-paint, to a thickness of appox. 40 micron. Bare metal must be primed with Primer, immediately after surface preparation to avoid contamination and surface deterioration before coating, and to obtain maximum adhesion to the surface. Check surface temperature before coating as metal surfaces are prone to varying greatly from the ambient temperature.
6. Fair areas which have been filled, apply further coats of primer to encapsulate the filler.
7. Allow to dry fully before applying antifouling.
8. Start painting from tiecoat to appropriate manufacturer’s specification.
BTW: The term is "fairing", as in to make smooth and fair.