Turning Archive 2006
>I have been chatting with Vince (VincesWoodNWonders) who has the wonderful blue sanding film discs, and have been left with a real head scratcher. What are the optimum speeds for sanding? There is lathe speed, disc speed, and pressure to consider. Somewhere there has to be an ideal combination that will yield fastest removal and smoothing without heat build up which of course leads to glazing of the disc and wood, heat cracks, hook and loop pad (and some times glue) failure, and burning the woods. What is too fast? What is too slow?
I have both the slow and high speed Sioux/Milwaukee angle drills. At first I liked the high speed ones. Now I like the slow speed ones. I have found that the slow speed model gets the job done just as fast as the high speed one, and is easier on the wood, pads and discs. When I had to use the high speed one while my slow one was down, I put a piece of cork under the trigger to keep the speed down. Vince told me that he recomends a disc speed in the 700 rpm speed (slow speed drill is 1 to 1,200 rpm) on the coarser grits and slower than that on the finer grits.
I like to turn green to final thickness, let them dry and warp, and then sand and finish. For lathe speed, ususlly I am in the 100rpm or less. I usually keep the trigger all the way down if for no other reason because this is the easiest speed to maintain. I have found that the firm pads are much faster to use than the soft pads, and the firm pads from Vince that have rounded over edges (I would guess 1/4 inch radius minimum) work very well on the inside of the bowl. I have, at least for the time being, been sanding up to 180 or so with the firm pad and then switching to the soft pads for the higher grits, 220 and up.
I also dry sand. I have seen some who wet sand with oil. Does this make much difference other than the dust factor?