Thanks Mr. Paint.
I phoned up the teck help line. The lady I spoke with was vary helpful. After duscussing the situation we came up with using 18 inch square instead of th 28 inch square. I'm I Arizona and the wall I am painting gets sunlight through out the day. Also we have 10 foot high walls. We concluded the paint was drying before I got part way up the wall.
Conclusion, smaller squares, and I am going to paint when the sun goes down. I'll post my results
after I paint this weekend.