Wow. A relatively simple process made complicated. The steps are simple but take a lot of words to describe.
1. I am not a pro. Just a practical tinkerer.
2. This kit is about half the cost and unless the scratch is huge, probably adequate.
http://www.discountmarinesupplies.c...kajaboBLGFXiaWdKRq_Slo2OsPzdfHfhoCuyAQAvD_BwE
3. Matching the color is the trickiest and most tedious part. What I do: on a piece of clean plastic cutting board, use a thin piece of plastic such as a playing card to mix up the colors you think are right, in an amount that looks like it will fill the scratch.
Do not add any catalyst until the color match is just right. Back and forth motion is better than circular stirring. Kind of a scraping and folding motion.
4. Wipe a little on the boat, near the scratch,
not on it.
5. If it is not a good match, wipe it off, add apropos pigment, and remix.
6. When repeating steps 4 and 5 produces a perfect match,
then add the correct amount of catalyst and mix thoroughly. Same motion.
7. Use a thin, flexible blade, such as a painter's palette knife, or a thin piece of plastic, to smear the catalyzed mixture into the scratch, leaving it a little proud (above the edges).
8. Allow it to cure until it will not dent with a fingernail. Might take overnight.
9. With 120 grit sandpaper
on a sanding block, gently sand in the long direction of the scratch (not across it) until the scratched area blends smoothly with the rest of the hull. Shine a light on it from various angles.
10. Shift to 220 grit wet or dry sandpaper, doubled over,
fully wet, and sand gently to smooth the scratched area. Rewet and rinse the wet or dry sandpaper frequently.
11. Repeat step 10 with finer grits of wet or dry paper: 400, then 600. The scratch should blend in with its surroundings, but the scratched area will not be as shiny as the rest of the hull.
12. Hit the auto parts store for some polishing compound and follow instructions to reach a uniform gloss.
13. Wax as you see fit.
If you screw it up, just haul out some 80 grit on a sanding block, take off the top sixteenth of an inch or so, and redo it as above. If you end up with some small voids revealed during sanding, patch with gel coat, sand smooth, and call it good.