An e-mail from Jan in Verona Ontario:
Last year I made a white cedar adirondack chair. I finished it with Varathane Natural Oil finish for interior and exterior wood. Parts of it are fine other parts are black after sitting outside one summer. I'm in the process of making another one. What can I put on it to keep a natural look without the black. I don't want to refinish it every year.
Response:
I finally got to have a chat with the chemical people at Minwax. They suspect that the relatively fresh cedar still had a lot of tannic acid in it (only way to get rid of it is a couple of years of air drying before finishing) that came through the oil -- and it will come through any oil. Their recommendation for cleaning it up is to clean it with a "wood restorer" such as is sold for decks and fences (not the bleach based one that will ruin the colour of your cedar but one that says that it "removes wood fibers") Thompson makes one called "Deck Restorer" but there are other good brands out there as well. They are not "wood cleaners" but "wood restorers". Then the suggestion is to use a cedar tone penetrating stain with UV filters rather than finishing with an oil. This will tend to trap the tannic acids inside, as well as not let them react with the sunlight (black colour). Let me know how you do.
Jon