It depends on how large your spots are. It should not take a lot of git-rot to do it. Unless the delam is really bad, there's not usually all that much space to fill. The trick is to make sure you get into all the gaps and don't let it leak out. Start at the bottom and use masking tape to cover the holes as you go up. Be very careful not to drill through to the inside of the hull.
I did a spot about 10" x 10" on the top of my hull (where the trailer strap crosses) and used less than 1/3rd of a small bottle.
oh yea, don't use straps across the tops of your hulls.
