Preparing Your Boat for a Bottom Paint Job

Preparation is key when painting on any surface. Applying bottom paint is not the cleanest of jobs, but it is really simple to do. Below you will find the exact steps to insure a good bottom paint job, whether you have a new boat, or a boat that has existing bottom paint on it.

Preparation for Bare Fiberglass
When painting a bare fiberglass gel coat hull for the first time, it is extremely important that all contaminants such as grease, oil, wax, salt, or other foreign material are completed removed prior to sanding or application of a Sea Hawk System. Scrub the surface with a detergent soap and stiff bristle brush.

Clean your boat following options A or B

A. Clean and de-wax fiberglass hull withS-80 Wax N’ Grease Killer solvent based dewax. Saturate cheeseclothrag and wipe thoroughly to remove any cleaner and contaminants. Be sure to remove any residue before it dries and change rags frequently to insure contaminants are completely removed.

B. Apply S-90 De-Wax Etch & Cleaner with a maroon 3M Scotch-Brite® pad scrubbing thoroughly. Do not allow cleaner to dry on the surface and remove by flushing with water.Rinse entire surface with water and check for any beadingon the surface which will indicate that wax is still present. If necessary repeat step 2 again until the surface is contaminant-free. Choose your system below.

Sand & Clean

Sand to a uniformly frosty, dull looking surface with 80-100 grit (no finer) sandpaper, rewash with S-80 Wax N’ Grease Killer , S-90 De-Wax Etch & Cleaner .


Apply Bottom Paint
Apply a minimum of two coats of Sea Hawk bottom paint. Allow 3 to 6 hours between coats and a minimum overnight dry before launching. See the specific Technical Data Sheet for the bottom paint you are using. Some bottom paint may require more than 2 coats.

Tip: Epoxy systems on the bottom of bare fiberglass is the best way to protect your boat against blisters. It also provides added adhesion of the bottom paint to the hull. 

Preparation Over Existing Bottom Paint

Clean the boat
Clean the existing boat bottom paint with a pressure washing. If you have excess build up of growth, you can remove this by scraping and/or using muratic acid. Try to get all growth residue off the existing old bottom paint so that you have good adhesion of the new bottom paint.

Scuff Sand the surface
Scuff sand to a dull looking surface with 80-100 grit (no finer) sandpaper, then rinse with water and allow to dry. If your old bottom paint is really chalky, consider giving it a more agressive sanding to insure proper adhesion of the new bottom paint.

Apply Bottom Paint
Apply minimum of two coats of Sea Hawk bottom paint. Allow 3 to 6 hours between coats and a minimum overnight dry before launching. See the specific Technical Data Sheet for bottom paint being used. Some bottom paint may require more than 2 coats.