I would not dilute it much with water if you are going to be spraying it as this could increase the chances that the paint will sag. If the paint is too thick, I may add water until the paint seems workable, usually not more than a few ounces though.

Darn. Opened a can, poured the content in the sprayer, but it was way too sticky, barely dripping from the sprayer. So I have added the same quantity of water. Then I have made a mistake and added yet another measure of water making it 25% paint, 75% water. Half of it trickled along the (vertical) fence tin sheet and made a mess around. So for anyone else trying to do it himself... be cautious. Oh, and, using a pressurized sprayer seems not a very good idea as it will sprawl the paint. I did paint unintentionally, making the mess even worse :-S

I use an HVLP sprayer and I use about 75% paint, 25% water and a few tablespoons of Floetrol. If your mixture is a little bit thicker than heavy cream, you're good to go. Just make sure you do lots of thin coats!