The expensive primers clog more often because their nozzles are designed to produce a finer spray.

For best results:

1. Heat the can using hot water. Just put it under a faucet running hot water for 5 minutes or so.
2. Spin the can rather than shake it. Be sure the paint is mixed. Three or four shakes is not enough.
3. After spraying turn the can upside down and spray
4. Consider the weather
5. Store your paint can inside. Cold weather can cause clogging.