Treated lumber contains special chemicals that are reverse-vacuumed into the wood fibers. These chemicals make the lumber resistant to rot and infestation. They also make the lumber resistant to paint. AC2 treated lumber is different from most types of treated lumber because it does not contain harmful chemicals like arsenic. Unfortunately, it poses the same problems when it comes to paint adhesion. The chemicals within the wood prevent paint absorption, eventually leading to heavy flaking. Before you can paint your AC2 treated lumber, you will need to demonstrate considerable patience.
Move the AC2 treated lumber to a sheltered area, or cover it with tarps to protect it from rain. Wait six weeks for the AC2 lumber to dehydrate.
Clean the dehydrated AC2 treated lumber using a pressure washer. Wait a full day for the AC2 lumber to dry.
Pre-treat the AC2 treated lumber by applying an acrylic latex primer, using a 3 inch to 4 inch paintbrush engineered for use with water-based coatings. Wait two hours for the primed AC2 lumber to dry.
Clean a paintbrush with ordinary tap water.
Coat the primed AC2 lumber with an acrylic latex paint, using the clean brush. Wait two hours for the finished lumber to dry.
Use an acrylic deck paint if the lumber is intended for a deck.
AC2 treated lumber is infused with chemicals that make it ill-suited for stain and paint absorption. Do not begin the application process too soon or you will end up with chipping and peeling.
Do not paint unprimed AC2 treated lumber or the paint will peel.