Well, the thread under angle drill failure diverged to the point where I thought it was time to start a new thread. The title of 'No Tear Out' bowls is a claim I have heard from a couple of 'big name' turners, and is some thing that I think does not exist. Given that on standard bowl grain orientation, which is side grain, for 1/4 turn you cut with the grain, then 1/4 against the grain, then 1/4 with, and 1/4 against. The only turnings I have ever seen with no tear out are, in every single example, are all spindle/end grain turnings because with them you can cut totally with the grain. With the claims on bowl turnings, at best you get tear out down to levels where sanding is greatly minimized. When I go up to look at 'no tear out' bowls, you can see little to no tear out, but when you rub your hands over them, you can really feel it. Every single time. Shear scraping, very light cuts, very sharp tools do a good job here. The part I want to bring up in this thread is the fine edge. I prefer to do every thing with tools while the bowl is spinning. There are those who take hand held card scrapers to the pieces after they are done turning and before scraping, like John Jordan, and Prashun. During my process of trying to get things as good as is humanly possible, I have determined that the finer edge leaves a cleaner surface, but trying to find the perfect edge is a challenge because of so many variations. At present, it seems that the burnished burr on scrapers, and/or a 600/1000 grit edge on a gouge leaves the best edge. I am leaning towards the burnished burr on scrapers as having the advantage. What I am trying to figure out is what difference the various metals make, and that includes both the scraper, and the burnishing materials. For metals, that pretty much includes M2, M42, and V10. For burnishing, that includes the steel rods that you find at woodworking stores, carbide rod (Eric Loffstrom uses them), and I have heard of ceramic burnishing rods. I guess we could include honed burrs in here too. Which would include how fine of a grit is used. So, who uses what???
After seeing Eric demo, I made a carbide burnishing tool, and prefer it. I googled carbide rod and found Centennial Carbide in Minnesota, who carry micro grained carbide rod. I bought 100 of them, 3/16 by 1 1/2 inch long. I don't know if they sell 1 or 2 at a time or not. If any one is interested in trying them out, I will sell at cost, $2 each. Not sure if moderators are okay with this part or not, but it is experimental and not for profit... You can PM me, or contact me through my web site.
"If it ain't broke, take it apart and fix it anyway."
robo hippy