You can paint acrylic bathroom paneling if you improve its adhesive qualities prior to application. Like other slick, nonporous surfaces, bare acrylic panels will not hold a painted finish. To generate adequate adhesion, abrade the paneling. Choose the right paint based on the location of the paneling, or your new finish won't last very long.
Your acrylic bathroom paneling will likely reject its new finish unless it is completely clean. The cleaning process is especially critical for acrylic paneling located within a shower. Layers of transparent soap scum will not allow the primer base to adhere. For best results, scrub the acrylic paneling with a trisodium phosphate cleanser using a coarse nylon sponge.
Acrylic bathroom paneling is too smooth for primer adhesion. Alter its adhesive qualities by sanding the acrylic with 100-grit sandpaper. Ease the process by loading the sandpaper into a handheld palm sander. Scour the entire paneling, leaving no portion unsanded. Run your hand over the acrylic to ensure that it feels rough, or flaking is likely to occur.
Before the acrylic bathroom paneling will accept paint, it requires a coat of bonding primer. Ordinary latex primer is fine for acrylic paneling outside the shower; however, it may not prove adequate for paneling subject to consistent water exposure. Apply an acrylic primer to acrylic bathroom paneling located within the shower.
Latex paint is well suited for properly prepared acrylic bathroom paneling outside the shower. Though you can use an eggshell or satin paint, a semi-gloss latex paint will prove easier to clean. If you plan to paint acrylic shower paneling, use either an acrylic enamel or two-part epoxy.
Unless you're experienced using an electric or gas-powered spray rig, you should apply the primer and paint using a roller and paintbrush. Apply light coatings to prevent sagging. Touch up the acrylic bathroom paneling with a polyester paintbrush. These tools tend to provide slick results. Don't use a nylon paintbrush, or marks may show in the finish.