We want to use a water-based polyurethane on the underside of a porch overhang. We have have applied a water-based pickling stain to tongue and groove pine planking so as to allow a the grain to show and also compliment exterior paint and trim. Some products we have shopped are inappropriate due to amber color of the polyurethane. Behr offers a clear interior polyurethane that can be used on the exterior but we have been unable to find this product in our area. Other exterior products state they will become cloudy if not exposed to direct sunlight.  Does anyone know if all interior polyurethane products can be used on exterior wood if not directly exposed to sunlight and weather?