Re: how long to dry???
Peeling and flaking are going to be from a bad bond no matter what paint was used. If you did your prep right, used the proper system to paint it, then it will be fine once it cures....curing depends on the specific circumstances you are in. Temp of the lower unit itself should stay above 65 degrees, and you are looking at least 2 weeks to be fully cured and out of the woods. Some paints will take longer to cure and curing time will be extended in colder or more humid environments ( unless it's a moisture or UV cured product ).
Generally speaking, if you give it a month regardless, you should be cured.
The only thing that should happen to the paint is scratching or the bond being broken if the lower unit is struck by something very localized ( ie. a hammer strike and the paint chips )