Painting Plywood Sheet for Engine Room

This is the plywood sheet that my electrical components will be screwed onto in the engine room. I decided to start painting it before the foam is done in the engine room, that way once the foam is done I can just plop this on. I chose to go with an epoxy primer that is gray. I chose to do this because I have no idea what I'm doing and I could find instructions of how to use it online and could also find it in the store.