Hi, I am new to the forum. It seems like there are so many people with so many great ideas and talents, I am hoping to find a solution to my problem.

I have painted (w/outdoor latex paint) outdoor picnic bench for my daughter's school project. All the kids at her preschool did handprints with acrylic paint, and now I would like to seal it with some form of coating. I thought using polyurethane would be an easy way to go, but the guy at HD tells me that because it's painted and for outdoors, poly wouldn't work. The stuff (Helmsman spar urethane) he recommends for outdoors only works if the surface is unpainted.

Is there protective coating I can use for painted outdoor furniture?