We have decided to use wall paper in the living area and bedroom. In the bedroom we also will use the wall paper on the ceiling. The kitchen ceiling and living area will be painted.
In order to get good adhesion of both paint and wall paper I sanded the fibre glass with a 40 paper and cleaned everything with methylated spirits.
The next step was a bonding primer. In the kitchen and living area I used a spray gun and for the rest I used a brush for a thicker primer.
I have removed all windows and doors and have taped up the openings with wrapping plastic to prevent over spray onto the gel coat and to get around taping up the windows from the inside.
Below images show the sprayed primer flattened with a spatula.
Living area and kitchen ceiling is painted with a suede type paint in light cream.