[bobbader]

Agree with all said so far, but I note that the reducer can says "cool reducer".
If you've done this job in the current northeast heat, this could tend to allow the paint to "set-up" too quickly and cause dry spots. There should be mid-temp or high-temp reducers that might help your paint flow. I also agree that 40psi would not be a problem ................ might actually help ........ but practice on something else if you're going to increase pressure. Then, remember to focus yourself (not over focus and rush). Get yourself a pace that works for the expanse of the item being sprayed. Good luck.