Sandblast the hull with coarse sandpaper, until the gel-coat is completely removed, if it is covered with blisters. In case a few are present among the inner layers as well, these must be opened with a chisel one by one. However if such bubbles are too many to be singularly treated, the first layer of the hull must be completely removed.
Wash thoroughly the surface with fresh water. Let it dry for at least two or three months. IIt is particularly important to wash the surface also one or two days before starting the treatment. This is because the substances oozing from the fibreglass affect adhesion and moreover, being water soluble, they would attract water from the inside, creating the possibility for blisters to form.
Apply one coat of PRIMEPOX using a brush, this product has a very good adhesion on both fibreglass and the gel-coat.
As soon as PRIMEPOX is completely dry, (this will take approximately 48 hours), sand the surface and apply two or three coats of BARRIER TIX or GREEN. The two coats must be applied within 24 hours from each other when the temperature is about 18°C. If the temperature is higher the product will dry faster and therefore the maximum interval of time between each coat must be of maximum 16 hours or even less. The quantity of BARRIER to be applied when restoring the hull is of 0,5 litres for each square metre of surface.
Let BARRIER dry for at least 48 hours, then sand the syrface with medium sandpapert (n. 120-140).
Apply one coat of FIBERGLASS PRIMER after sanding the surface with medium sandpaper (n.120-150) and then apply two coats of antifouling SUPER 505, MARLIN TF, MARLIN CF or MAXIMA, insisting with a third coat on corners and rudder.
Sand the surface with rather coarse sandpaper (n. 100-120), then let dry for 2-3 months (important if the boat is old), washing the surface with freshwater at least every month. Wash the hull two days before starting the treatment.
Apply three coats of PRIMEPOX leaving 12-16 hours between coats (if longer sand the surface between coats with medium sandpaper).
Then after 48 hours apply one coat of FIBERGLASS PRIMER and after at least 4 hours 2-3 coats of antifouling.