Primer soaks up moisture like a sponge. If that primer on the bed has been exposed to the weather, sand it all off and start over. Otherwise, you'll be trapping a layer of moisture under the finish which will lead to rust problems and/or paint lifting in the future.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!