Should I Prime My (Painted Grey) Garage Walls Prior to Painting White?

Question

Painting grey walls white - both paints are from the same base (Valspar 2000 Interior White/Pastel).

Will priming help before applying white paint, and if so, and how many coats of each (prime and/or paint) is recommended.

Answer 1

Depending on the shade of gray, you're going to need a lot of cover. That is one of primer's jobs - lay down a high-hiding effect that will render the surface uniform/consistent. Since your topcoat is compatible, whether you use primer for coverage vs paint is a costing issue.

I would physically scuff-sand the old coating, especially if it's gloss. The goal is to give the surface some microscopic mountains, or "tooth", so the new paint has something to mold into, and you're not trying to paint a mirror. If you see peeling paint in rental properties, that's why - quickie paint jobs laid over gloss paint.

You also want to carefully clean the old surface with soap and water, preferably one made for paint prep that leaves no residue. That's the other reason rental property paint jobs tend to fail.