I am mostly a bowl turner. A few years back, I started fooling around with scrapers on my bowls because I knew that some turners used only scrapers on their bowls and they looked as good as mine. A scraper is now my primary roughing tool on bowls, and I prefer it as a shear cutting tool as well. I have never been able to get the 'drop the handle and use the swept back edge of the gouge' cut to work well for me. The scraper just works better for me. For a roughing cut, keep the scraper flat on your tool rest. For finish cuts and clean up, keep it at a 45 or so degree angle for a shear cut, which is much cleaner than a scraping cut. One advantage of using the scraper for roughing is that it deflects the shavings up over the top of your hand rather than across the top of your little finger, which after a long day of turning can be rather irritating.
Note here, as far as I am concerned, 'shear scrape' is not accurate, you can do a shear cut and a scraping cut with any cutting tool out there, gouges, scrapers, skews, ets. You can also do a shear cut with the same tools. You really can't shear scrape, but you can use a scraper to shear cut. Personal rant now done.
Using a scraper to clean up what you have done with your gouge is not wrong. The thing to remember is that with practice you will get better with your tools, and there is a point where you can't do any more with what you have, so time to move on, and remember that the next one will be better. How many times have you heard the story about "I made one last cut and...... disaster. A scraper used for a shear cut will do wonders for cleaning up things that you can't quite get done with your gouge. As with any shear cut, this is clean up and not stock removal, so it will take a number of very light cuts. I prefer a scraper that is swept back on the left side for both inside and out side the bowl. A round nose scraper can do both as well, and you only need a round nose if you are mounting on a waste block and/or face plate and turning both the inside and out side of the bowl with out reversing and remounting to turn the inside. This is why they call a scraper that is swept back on the right side an 'outside scraper'. For me, I sharpen to a fairly blunt 80 degree angle or so. I use the burr from the grinder rather than burnishing one on the scraper. I do use a finer custom grinding wheel on my scrapers (CBN-cubic boric nitride compound). I do hone off the old burr before putting a new one on. If any of you get the AAW magazine, they just did an article on scraper edges, and the conclusion was that the best cutting edge (checked with a fine microscope on both the steel, and on some popolar cuttings) was that the cleanest cutting edge comes by honing off the top edge, then raising a burr with a diamond hone. I am still experimenting with this, but feel that my grinder burr is better.
I do prefer a gouge cut finish, but can never seem to get a final cut with no ridges or small lines that need to be taken out either by sanding or shear cuts. I am getting better, and have done a few pieces that need only minimal sanding. I always start sanding at 120 grit. I turn green to final thickness, let them dry and warp, then sand and finish. It seems like any small marks from cutting get bigger when drying. Never figured out why. I do round over the heel of the gouge for the finish cuts on the inside of a bowl. This has done wonders to improve the cut there. The inside has always been more difficult for me, and apparently for most other turners. This rounding over, or even grinding a secondary bevel (removing about half or the flat part of the grind) has done more to clean up the inside cut than anything else I have ever tried. Saves at least one grit of sandpaper. I do roll the flutes slightly away from the cut (to the left on the outside, and to the right on the inside) when finish cutting.
robo hippy
