- 2-component epoxy primer paint for painting fibreglass hulls under the waterline to prevent osmosis. *Provides effective protection against water diffusion in the laminate. *Suitable as a primer on all types of polyester and epoxy laminates, such as steel, galvanised steel and aluminium. *Not suitable for use on stainless steel. *When mending more extensive damage and cracks, or when levelling cavities, epoxy filler must be used first.