And if you blast it ... you will still have pits of rust that were too small for the blast media. Blasting is NOT a solution to rust unless you're refurbing a bridge. Get rid of the majority however you choose BUT the surface absolutely has to have a final treatment with a liquid that will either remove or convert the minute rust pits.
you seem to know lots about blasting sheet metal. whats your experience in blasting cars other than what you read on the internet?
