Painting under the waterline


Painting your hull is just as important as painting above the waterline. It is necesarry to apply antifouling to prevent fouling attaching to your hull. Fouling decreases the performances of your boat. Heavy fouling makes your boat dangerously slow and difficult to manoeuvre in an emergency. SEAJET antifouling gives your boat the best protection.




Make sure you check the weather conditions before painting. Temperature, dew point and humidity will affect your paint job. Weather considerations can be found on the product data sheet. Check if your antifouling is compatible with the current antifouling. If you don’t know what antifouling was last used the best solution is to apply a full sealer coat of Seajet 015 Underwater Primer on your boat. This will give good adhesion to the following coats.


Surfaces to be painted must be clean, dry and free from oil or grease. Apply a good quality masking tape around the waterline, and mask off anodes, shafts and fittings to protect them from unwanted antifouling. Stir the paint thoroughly with a stirring stick. Heavy biocides in the antifouling can settle to the bottom. Thinning should not normally be necessary.


Applying antifouling


Antifoulings are best applied with a roller, but keep a brush handy for those areas that are difficult to reach with a roller. Mohair rollers are recommended. Apply according to the recommendations on the label. When using a roller, apply the paint in a ‘criss-cross’ pattern. This helps spread the paint evenly. Apply the correct thickness mentioned on the data sheet. Apply an extra coat on the waterline and leading edges.


Ready to launch


Follow the overcoating times carefully. Allow the paint to dry before immersion. True colour will be seen after immersion because there may be some colour fade when polishing starts to release the pigments.