Well, after the Symposium in North Carolina (I think it was North) some years back, a bunch of people were ranting and raving about this new guy with really good abrasives, Vinces-WoodNWonders. I had to experiment, and really liked them. I did chat with him, and he started me on slow speed sanding. Before, I had the trigger on my drills pushed all the way down. He said slow speed sanding worked better, so, being the curious sort, I had to try it out, and found out that it did seem to work better than full speed, and I have both high and slow speed drills. I also found out my drills lasted longer before the bearings went, from 300 plus bowls to 400 plus bowls (note here, I am rough on my tools). What drove me crazy was trying to figure out why the slow speed sanding worked more efficiently. I may have it now, thanks to a comment from Jimmy Clewes. He said that he doesn't think abrasives are cutting tools, they really just scratch the wood. I pondered that, and thought, well the difference between the steel and the abrasives isn't the serrated profile of what is cutting, it is on a steel tool, they are on a line/knife edge, and on abrasives they are on a plane or flat surface. So, both are cutting, but slightly differently. With a knife edge you can dig in as far as your lathe, tool size, rpm, torque, handle, and personal strength will let you. You can't do that with abrasives because they are on a bigger surface. With slow speed sanding, if you are at high speeds, the abrasives never really have a chance to dig in and get real traction to cut effectively. The abrasives will skip a lot more. I find myself now with the trigger mostly at 1/4 to 1/2 speed max, and most of the time it is in the 1/4 speed range. My lathe rpm is at 15 to 20 rpm, but that is because my bowls are warped, and if I go any faster than that, I can't keep the abrasives on the wood. It really does seem to work much better.
robo hippy