I am 73 with 2 torn rotator cuffs and yes it is hard work and the shoulders do take a toll when doing the cleaning and waxing. the buffing was the hardest, but it was the process that made all four sides shine. I took a couple Tylenol before I started and a couple Ibuprofen when I was finished for the day (it took several days). The Scotch tasted much better after the hard days work!
