This might be a stupid question but here goes. I took down some window boxes on the front of my house, then decided to put them back up after cleaning them. The PO left an unpainted area behind the boxes the last time they painted the house (white). I have a can of white Rustoleum Painter’s Touch ($8) that I bought for something else. Can I just use that to paint the raw cedar shingles before putting up the boxes, or do I need to go buy a quart of exterior house paint? If they even sell it in quarts.