I was once given an assignment at my job that I was 100% under qualified for. There was 1 week where I put in probably 100 hours. I remember one day putting in 19. I sucked at that. I never got good enough at it and was eventually replaced with someone that could do what I couldn't do and even do it in a normal 8 hour day. I was so thankful to be done with it. Moral of the story, if you're not qualified, it doesn't matter how hard you work.