Here's what I did last season. 1st applied simple green and let sit then scrubbed, then Power washed with simple green, and rinsed, dried. I used Awlgrip and brushed on heavy. Don't use to much activator and don't use the hardener if you have time to let the paint set for a week. make sure you have plenty of ventilation and to the other guys comment, let people know where you are and what your doing. By a professional respirator before applying, a Tyvec suit with hat, gloves, safety glasses. This is not for the faint of heart, Awlgrip is serious stuff but works great.