As state above...the instructions are fairly clear on the conditions. Most want it above 50f and dry. Many will make a statement like the hull should be 'dried out' for at leasts a min. of 24 hrs (In other words, if it stopped raining at 5 pm, don't start painting at 8am the next morning.).
The temperature and humidity will dictate drying times and min. times between coats.
I find there are several major contributors to bottom paint failure:
1) Insufficient Cleaning of Hull (every last piece of growth needs to be removed)
2) Insufficient Sanding of hull (this includes prepping paint for a new coat). People don't sand nearly as much as they should with too high a grain sandpaper.
3) Insufficient removal of dust after sanding (paint indicates what should be used to wipe down the hull. to have all dust properly removed it needs to be done more than once or at least with some attention to detail. (If you've wiped down the entire hull in 30 min. there's junk left behind).
4) Painting with the hull is wet. (I've seen people wash the hull with a hose, bucket and brush, then go to lunch. when they come back it 'looks' dry so the painting begins.
5) Painting when it is too cold. (I take the min. temp. advised by teh manufacturer and add a min. of 5, and usually 10 degrees. You can feel the difference in how the paint goes on the further from teh min. temp. you get.)
