How to Repair a Skill Saw Cut in a Boat Hull
- 1). Remove the interior components of the boat with the mechanic's tools to allow you access to the back side of the cut. You cannot simply apply the patch to the outside of the hull, it must have a strong backing.
- 2). Clean the inside and the outside of the cut with wax and grease remover, and then thoroughly scour both sides of the cut with the 80-grit sandpaper. This gives the fiberglass filler a good surface to bite into, strengthening the repair.
- 3). Mix the fiberglass body filler with its catalyst on a scrap piece of cardboard with the putty knife or a plastic paint scraper. Use approximately 10 percent catalyst to the amount of filler you are using, mixing thoroughly until the body filler is one color.
- 4). Apply the body filler first to the backside of the cut with the paint scraper or putty knife, pressing the fiberglass until it squeezes out through the crack to the outside of the hull. Apply more fiberglass filler than you need. It does not need to be sanded flush with the hull.
- 5). Apply the remaining filler to the outside of the hull, making certain that you completely cover the crack and spread the fiberglass out over the scratches made by the 80-grit sandpaper. Allow the fiberglass filler to cure completely before sanding. The filler will grow hot as the catalyst reacts to it. When this warmth has dissipated, it is time to sand the hull.
- 6). Wrap the 80-grit sandpaper around a sanding block and then gently smooth out the high spots of the repair to the outside of the hull. Once the body filler is nearly flush with the rest of the hull, change the sandpaper to 180-grit, and then finally 400-grit.
- 7). Spray the surface of the hull with the marine touch-up paint, and then allow it to dry completely before proceeding.
- 8). Gently sand the touch-up paint with the 800-grit sandpaper until it is completely smooth and running your hand across the repair gives no indication that there was a cut in the hull.
- 9). Apply a small amount of polishing compound to the orbital buffer, and then proceed to polish the sanded touch-up paint until it has blended with the surrounding hull paint and has a deep, rich gloss. When complete, reinstall the interior components removed earlier to complete the repair.
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