I just finished doing mine. The best thing I found to evenly spread it was a foam roller. I tried other tools and this by far worked the best. Denatured alchohol cleans it well as said previously. Also, I'd suggest scarifying the bottom well with a peanut grinder, sandpaper isn't enough. I bought my boat from a certain shop in Woodinville and they 'threw in' the coat-it bottom. However, since there wasn't much in it for them they did a quick job using sandpaper and it peeled off something fierce. I took the time to remove every bit of the old before applying the new. One gallon was just right for a 16' boat with some to spare. It took 2-3 days at around 60 degrees to set up enough before I felt comfortable sliding it back on the trailer. Good luck!