flakeing paint

[RICHARD OXLEY]

help needed to stop paint flakeing when spraying with cans.tryed the usual washing shell,scuffing with scoring pad and heater on shell between coats.tryed tamiya,pactra, and custom colur but always get some flakeing looks like paint has not bonded to shell properly.would a coat of nitro block first then left to fully harded help or would this dull the final finish? thanks rick.