Development of a natural finish with long-term performance should assist wood products to maintain market share in residential applications in the face of substitute materials and potentially expand markets in recreational property and non-residential applications. A range of commercially available products, reputed to be among the best in their class, were exposed for two years accelerated natural weathering facing south at 45o at test sites in Vancouver, BC and Gulfport, Mississippi, the latter in collaboration with the USDA Forest Products Laboratory. A range of pre-treatments were evaluated under these finishes including sanding, “mill glaze” treatment, chromated copper arsenate treatment and several zinc-containing formulations expected to provide some protection against UV and mold/stain. The test material was inspected every six months for discolouration, mold/stain, finish water repellency, flaking, erosion and cracking and substrate condition. Two variants of a water-based film forming finish stood out among the products tested after only one-year and showed little or no deterioration (with the right surface preparation) after two years exposure in Mississippi. With regard to the pre-treatments, sanding doubled the time to refinishing for the water-based film forming finish but had no effect on a solvent-based film forming finish. “mill glaze” treatment increased the refinishing interval, but was not as effective as sanding. Chromated copper arsenate pre-treatment doubled the life of the solvent based film forming finish but did not affect the water-based film forming finish. Zinc naphthenate pre-treatments negatively affected finish performance and zinc acetate provided no improvement in performance. The Mississippi test site provided a factor of acceleration of about 1.3 for film forming natural finishes compared to the Vancouver test site. Based on this acceleration factor, the water based film-forming finish F5 over sanded wood would be anticipated to give a life of at least 4 years without refinishing in high-end applications under Canadian conditions. All the other products tested required refinishing after 1 year or less in Vancouver.