I'm making a picnic table for a co-worker. I had it covered with a tarp (that I now know had a hole in it) so it wouldn't get wet while I was waiting for a clear day to finish it. I've sanded away at it to see if I can get rid of the black spots and streaks. No luck yet, it seems to go pretty deep. What should I do to save it? These pictures aren't the greatest. The sun I've been waiting for is now too bright for pictures. I can't win for losing. Thanks for any suggestions.