Aerosol Etching primer

[01somta]

I am getting ready to spray an undercoating (u-pol raptor) on my new floor and trunk pans, do you see any problems with me using a Aerosol can of etching primer on the entire surface before I spray the undercoating. The reason I ask is because I have heard that you should not use the aerosol can on anything bigger than a Silver Dollar. I don't have a spray gun, so this seems like the only choice. Please let me know your feedback or personal experiences.