Ken Collier: Primers are one of the secret weapons of pro painters. And that can help you get perfectly smooth walls with even gloss, exact color, and perfect coverage. They'll save you time, they'll save you money. However, primers are also a very confusing group of products. I counted 21 different kinds of primers at my local home center. My name is Ken Collier and I'm the Editor-in-Chief of The Family Handyman magazine, the leading brand for do-it-yourself homeowners. Today, we're going to cover five situations where you should consider using a primer. We'll also cover which primer to use; very important question, and the tools you need to apply your primer. Now the five situations we're going to cover are first of all stains on your walls, and that would include things like water stains, ink, anything; patches, and of course, everybody has patches on their walls when they're repainting. Painting over glossy surfaces like glossy trim or metal, drastic color changes, for example, if you want to use one of those deep reds that are so popular these days. And finally, bare wood, a fairly common situation. We'll cover the difference between oil primers and latex primers, and also this intriguing new primer-paint combination that you can find now. But before we get started, here are a few tips that are true regardless of what kind of primer you're going to use. First off and very importantly, primers are not a substitute or thorough preparation. You still need to wash the surfaces you're going paint very thoroughly, and in some cases, sand them as well. Secondly, you should recoat the primer as soon as possible after it's dry. One to two days at the very most. And so make sure that your top coat sticks really well to the primer. The third thing is talk to the paint expert behind the counter at your local paint retailer, whether it's a home center or a paint store. There are so many different situations with painting and there are so many different kind of primers, you should get their advice on exactly what primer is best for your situation. And finally, read the back of the can. Experts in the painting industry say that the vast majority of problems with paint occur because the person painting didn't follow the directions on the back of the can. So now let's get started learning about primers.