How to Grind Out Stress Cracks & Repaint a Hull

A boat's hull should be examined regularly for peeling paint and stress cracks.

From the rough exterior of a dugout canoe to a finely planed planked bottom, a boat's hull is the most important part of a floating vessel. While dugout canoes were the norm in ancient times, hulls are often larger and made of more advanced materials today. However, proper maintenance ensures it will last a long time. Removing stress cracks and painting the boat to prevent water from entering is vital to good boat maintenance.

Things You'll Need

• Safety mask, gloves and goggles
• Boat, on stilts and housed
• Hand sander
• Grinder
• 100-grit sandpaper
• Epoxy filler
• 80-grit sandpaper
• 120-grit sandpaper
• 220-grit sandpaper
• Epoxy primer
• Paint roller
• Boat paint, in desired color

Instructions

Grinding

1. Ensure the work area is dry and clean before you repair and paint your hull. Examine and test how stable the boat is on its supports before working. Wear safety mask, goggles and gloves to work with the sanding and painting materials. Ensure the workspace is well ventilated.

2. Cover the bottom of the sander with 80-grit sandpaper, or larger if needed, to remove layers of paint. Have the grit side outward. Sand down the entire hull through the base of the hull.

3. Examine the hull for any stress cracks or large gouges. Plug in the grinder and grind down any of these areas, using 100-grit sandpaper.

4. Brush away all dust and debris from the boat. Apply the epoxy filler to the cracks and gouges in the boat. Allow the repairs to completely dry, which generally takes between 24 and 48 hours.

5. Sand down the applied and dried epoxy so that it is level and smooth like the boat's surface, using the 80-grit sandpaper. Sand the entire hull using the 120-grit sandpaper and then the 220-grit sandpaper to create a smooth surface for painting.

6. Brush any dust and debris away from the exterior of the hull. Paint on one coat of the epoxy primer.

7. Allow the first coat of paint to dry according to the manufacturer's directions. Apply another, allow it to dry. Paint on a third coat if any old paint is still faintly showing.

8. Paint over the primer with one even coat of the final paint in your desired color. Repeat this two more times with the paint to ensure it is even and completely covering the hull.

References

• Triton 381; The Hull
• Power and Motor Yacht; Boat Scratch Fever