So I'm building a jazz bass with a natural finish on a swamp ash body. After reading the many positives of Birchwood Casey Tru Oil I decided to give it a try. I really like how it is looking so far. I have read posts were it says it will take 30 coats to finish it properly. Is that really the case? I'm on coat eight right now. 30 just seems excessive. What is the benefit of that many coats and how will I know when I have enough?