 And the primer is the glue, the adhesive coat. That's what makes the paint stick. And then you put the top coat on top of that. Now, will this peel on the south side where the sun hits? No, not if you do a good job on the prep. That's why we're telling you to prime it. And because the siding is metal, that paint job should last you a good 8 to 10 years. It lasts less if it's an organic material like wood siding, but with metal siding, it can last a long time if it's done well.