In sun all day.
Try using deck sealers.
Hi Shirley, take a look at this video: https://www.youtube.com/watch?reload=9&v=MAmye6pDRnc
Coat with Marine Varnish
Hi Shirley, you may want to switch to a marine-type paint used on boats. It is tougher than most paints as it is continually subjected to wind, water, and sun.
You can varnish with a marine varnish, the same kind used on boats.
water based polyurethane -multiple coats;2 part epoxy coat/dip them https://www.youtube.com/watch?v=oY6JMxYrAoQ