I have about one half gallon of flat wall interior latex paint that has been stored for about two years. I was planning to use it to paint some decorative birdhouses (not real outdoor birdhouses). The paint is a little too thick and syruppy. Would it be okay to add and mix about a pint of water to it so as to make it a little thinner and more manageable with a brush? It doesn't say anything on the label about using water or anything else to thin it. I don't want to mess it up and render it unusable. I don't want to have to drive 20 miles to buy some new paint just to paint those silly birdhouses for my wife. I'm hoping it can be thinned with water. Thanks in advance for responses.

I recently bought a Wagner and used it to paint new cabinet doors for family room. Did it pretty quickly and the doors came out looking good. But the one problem I had with the Wagner power painter was frequent clogging. Could only get 1 or 2 doors painted before it would clog and I would have to stop and remove and clean the little valve that is removable fromthe nozzle area. (I used latex paint purchased at Ace Hardware.) I've been told that the secret is to thin the paint substantially. Is that correct? If so, is there a rule of thumb for how much thinning the paint can stand? Also, my next project also involves painting doors, and I assume I have some options as far as type (latex. oil-based, etc.) and brand of paint. Is there a particular paint (type or brand) that is known to work best in these power painters (i.e., infrequent clogging, good result, etc.)? Thank you.