How do I fix the hull on my boat?

Question

I have a 19ft deep v fiberglass hull. It has some scrapes and gouges especially in the v near the front and middle. It looks like the previous owners probably would run it up on beaches or rocks. It is not the whole way through but they are deep. I was thinking of using a paint brush to paint on layers of fiberglass resin on it. They aren't really big enough to put fiberglass cloth in it. Any help appreciated.

Answer 1

The Repair

Before you begin, wash the area with soap and water and rinse it thoroughly. If the surface is oxidized, restore it with a rubbing compound so you’ll be able to match its color accurately. Once the surface is clean and dry, mark off the repair area with masking tape.

Next, gouge out small, narrow cracks (and scratches that are too deep to remove with rubbing compound) until they are wide enough to fill with gel coat paste. A miniature grinding tool like a Dremel is ideal, but the sharp point of a can opener will work, too. (If you don’t open the crack, you won’t be able to force the gel coat into the repair area or expose enough surface area for the repair to adhere.) Then sand lightly with 220-grit sandpaper. After sanding, thoroughly clean the area with acetone to remove the sanding residue and any waxes or other contaminants that might interfere with the bond between the damaged surface and gel coat.

The next step is to match the color of your existing gel coat. Start with a white or neutral gel coat paste (not resin) and begin adding tiny amounts of coloring agent. Mix several test batches of gel coat and pigment, add hardener and allow them to cure (gel coat changes color during the curing process). Once you‘ve found an acceptable match (an exact one is nearly impossible), mix a final batch using the same ratio.

Next, using a putty knife, fill the areas to be repaired with the paste you’ve mixed. Force out any air holes and be sure to overfill, as gel coat has a tendency to shrink as it cures. When you‘re finished filling, seal the repair off from the air with a PVA curing agent or a piece of plastic wrap or wax papergel coat does not cure properly when exposed to air.

Once the gel coat has fully cured, sand the repair smooth (wet sanding works particularly well with gel coat). You can start with 220-grit sandpaper and, for a really slick surface, finish with at least 400- or 600-grit. Finally, apply a coat of high-quality marine polish and your repair is complete.

Answer 2

Sand first use a marine puddy filler then sand paint or bottom paint Or gelcoat>

Answer 3

A hole in the boat is usually repaired from the inside with fiberglass. However scratches and imperfections on the outside which is the gel coat are usely repaired easily with bondo and paint. Remember if its a hole this bondo will not repair it from leaking. Bondo is for the external appearance repair only.  Must make point of  a complete hole must be repaired from the inside!!