We have specialty lumber companies here in the south east that are selling pennofin for maintaining exterior exotics and cedar. I have been working for an owner of one of these companies for the past four years now and he has had me strip and reapply pennofin to his spanish cedar (yes, spanish cedar) and cumaru decks. I finally convined him to go with an alternative and have explained as best as possible about the pennofin oils turning black in the sun. Now I have another customer with the same issues on a very large cumaru deck. Why are these lumber importers still selling this? No doubt, the finish is beautiful for a short while. It has a sheen like interior floors and the color it brings out on exotics is great. However, it turns black and the only option is heavy strip. Does anyone know of a place online or other to send customers to educate them on the problem?? I have convinced my few, but would certainly like some back up.