I have a number of scratches and a couple of gouges on the hull.
One is pretty deep...not into the fiberglass, but deep into the
gelcoat. I'd like to patch them right away. Do any of you have
favorite materials and techniques? Ideally, I'd like to color-match
as much as possible to avoid painting the boat. Does that gel-coat
repair kit work, and how difficult is it to match the standard "GB
Matching the blue will be tough. The gelcoat repair kit should do
the trick. The key is in testing a few times to get the right
color. You’re dealing with epoxy resin, so be careful not to get
any drips on the boat. Also, factor in the time limit due to the
hardening agent. When you’re testing for color match also keep track
of elapsed time for hardening based on the number of drops of the
hardening agent you put in the resin.
If your scratches and especially the gouges are not even cuts, you
may want to even up your gouges. One trick is to use an old soda/can
opener. Run the can side (the end shaped like a V for like a Hi-C
Fruit Punch Can) though the gouges to even them out. Remember to
remove the boat wax from that area and sand a little around the edge
of the gouges.
Depending on how well you match the color will determine how good it
looks. However, you will still have good, permanent repairs, even
if the color is off a tad.
PS - If you don't mind the color gray, I have seen people use JB Weld
for the fix and then apply some touch up paint to match the required
color. This method is extremely easy but is usually noticeable.