Yesterday I put a coat of smw on my stepdads truck and it worked fine. I noticed he had very bad water spots on his back window so I grabbed an orange pad and the shr and started to buff. I spread it on and it worked fine, then I increased the speed to work it in and within seconds it made a horrible noise and shot the pad and backing plate off of the pc. Now i have a second backing plate with stripped threads and put a gouge about 1 1/2 inches long in his back window. What can I do to prevent this from happening?