I have found quite a difference in hardness of different finishes which requires a different touch with the tripoli. I switched to 4" wheels from the 8" because it was too easy to burn through the finish on some brands. I switched from Deft to a local lacquer which is much harder. Haven't burned through a singe one since changing. How much tripoli you apply, how fast the wheels is spinning as well as it's size, and how hard you push all affect how easily it is to burn through a finish. It's kind of like sandpaper. You don't really need a high speed to get the job done unless your trying to level the finish as well. If you get that aggressive it's very easy to burn through on any finish. I'm probably different than most people. I use the 4" wheels at about 2000 rpm. Surface speed wise that's probably a lot slower than an 8".