The testing procedure [in “The Great Stain Shoot-out,” Sep/Oct 2015] is interesting, to say the least. Did you test any semi-solid coatings? I have been refinishing exterior lumber exclusively for 25 years in San Diego, and over the years have tested more than 30 products in a variety of settings and profiles. To be 100% sure about coatings that I use, I have found it best to do my own testing. Even then, trying to convincingly sell my test results to clients—some of them with $200,000 decks —is very difficult.

What I’ve found is that all coatings perform differently, each with its own advantages and disadvantages, and that none of them would still be on the shelves if the product was total junk. For me, one of the most important factors in a coating’s performance is the ease (or difficulty) of re-coating. Easy initial application is great, but that only happens once: with new wood. The real test is with aged wood decking, especially on decks that experience varying amounts of sunlight or foot traffic. What I’ve discovered after 25 years in the business is that trying to compare the performance of different deck coatings can be a very slippery slope.

Jim Grant (from online comments)