I see some problems here ....
when you say it chips easily does it chip down to the metal ,epoxy or base coat ???
1:1 is great for spraying bare metal but to use as a sealer it needs to be reduced to get a slick enough texture for paint the reducer also speeds up the cure time..depending on what your trying to do ,SPI should be reduced from 10-40 %...a straight 1:1 mix can take up to 3 days to cure.
a 40% reduction can take 2hrs