thanks for you help,I guess I could use the 7 speed buffer i got a few years ago, but I found the buffer works faster and make the boat look good, but the finish doesn't look deep and doesn't fight the green and brown slime as well as the hand wax job. I'm not sure if the first coat is wiped off with the second but I can see the different between the coats. Since I only wax once a year , because the mooring waxing doesn't work well, the dingy just doesn't stay next to the work, I guess maybe next year I'll try the buffer again.