Hmm, so a McPhearson chuck is a variation of the Longworth chuck, which is a variation of the Cole jaws.... At least I think so. I don't use any of them. One friend who uses the Cole jaws uses the blue painter's tape to help make sure the bowl doesn't launch. I did try it once or twice. I do keep the rpm way down when I did that, in the 500 or so range, but I don't have a read out, so guessing, but way slower than turning speeds. As a scraper psycho, I would not suggest using a scraper for that cut. Also a very dainty touch is needed, not standard turning cuts for stock removal, more like 1/16 inch shavings. As a martial arts instructor (Wing Chung) says, 'Appetizer first, main course second.' but with this type of cutting there is no main course, you really have to nibble away gently. With the bevel rubbing cut approach, you still have to follow 'the bevel should rub the wood, but the wood should not know it' rule, so the bevel rub is not really pushing the bowl down into the chuck. That would create the wrong type of pressure. You can use a very light finger push on the wood, or your hand as a steady rest pushing in towards the chuck. If your hand is getting warm, you are pushing too hard, and/or your rpm is too high. This is just one more reason why I use a recess as my finished bottom for my utilitarian pieces. One less step, and less risk also. Maybe some day I might get a vacuum chuck...
robo hippy