JJ,
The red oxide primer should hold the ZR as that is it's function (adhesion promoter) but the primer layer then becomes the weak link in the chain and won't do much to retard rust growth sideways if the film gets compromised. That is one of the real strengths of ZR when applied direct to metal. A damaged area where the ZR is removed will rust but the film won't allow the blistering sideways to take place.
Also, FWIW, being a single package system, ZR repairs very easily too. I mentioned that to a customer this week and it really caught his attention. I go along thinking everyone has made all the connections about our product's strengths and weaknesses but maybe tossing some of these points out periodically will help.
