john lucas
AAW Forum Expert
I had time while my glue is drying on other projects to run this test this morning. You may not be able to see the details as well once I shrunk all the photos but I'll be glad to send you the bigger ones if you want.
Top row left to right, then bottom row left to right. Someday I'll learn to add type to these photos.
This is a piece of yellow poplar that had a patch in it that doesn't want to cut clean. I had already turned about 10 of these so I knew how it turns. The first photo top left is a 3/8" thick 3/4" wide flat scraper ground with a negative rake at about 60 degree included angle and burr raised by a steel rod which I have found is the best burr for this scraper.
The second photo is my 1/2" thick round scraper, same negative rake angle, burr off the CBN wheel, which again seems to be the best way for this scraper.
3rd photo is a skew laying on it's side, included angle about 43 degrees, no burr.
4th photo bottom left, the 3/4" flat scaper with burr held at a 45 degree shear scraping angle. You notice a definite improvement in the finish.
5th photo was a freshly sharpened bowl gouge with a 40 degree grind. A better finish especially on the end grain.
5th photo, a #4 Hunter tool. It's hard to see in the shrunk photo but it was a better finish still especially on the end grain.
I hope to have time to read all the scraper articles I've been collecting and to regrind a scraper into the very sharp negative rake grind that Stewart Batty has on his tools to see if it makes a difference.
As far as scrapers being used as the final tool for finishing I'm a little mixed on that. I do quite often because I turn fairly quickly and sometimes leave little tool marks and it's easier to use the shear scraper to clean these up. On smaller projects like boxes and quite often on my hand mirrors the cutting tool is the last finish and never touched by a scraper. The wood simply looks better if I can do it that way.
I did not include my Easywoodtool scraper in this test because quite simply it does not cut as clean. It did at first but after just very little use it won't cut nearly as clean as my flat scaper with a fresh burr. And I do mean very little use, mayby one bowl and few quick cuts to show students how it works.
Top row left to right, then bottom row left to right. Someday I'll learn to add type to these photos.
This is a piece of yellow poplar that had a patch in it that doesn't want to cut clean. I had already turned about 10 of these so I knew how it turns. The first photo top left is a 3/8" thick 3/4" wide flat scraper ground with a negative rake at about 60 degree included angle and burr raised by a steel rod which I have found is the best burr for this scraper.
The second photo is my 1/2" thick round scraper, same negative rake angle, burr off the CBN wheel, which again seems to be the best way for this scraper.
3rd photo is a skew laying on it's side, included angle about 43 degrees, no burr.
4th photo bottom left, the 3/4" flat scaper with burr held at a 45 degree shear scraping angle. You notice a definite improvement in the finish.
5th photo was a freshly sharpened bowl gouge with a 40 degree grind. A better finish especially on the end grain.
5th photo, a #4 Hunter tool. It's hard to see in the shrunk photo but it was a better finish still especially on the end grain.
I hope to have time to read all the scraper articles I've been collecting and to regrind a scraper into the very sharp negative rake grind that Stewart Batty has on his tools to see if it makes a difference.
As far as scrapers being used as the final tool for finishing I'm a little mixed on that. I do quite often because I turn fairly quickly and sometimes leave little tool marks and it's easier to use the shear scraper to clean these up. On smaller projects like boxes and quite often on my hand mirrors the cutting tool is the last finish and never touched by a scraper. The wood simply looks better if I can do it that way.
I did not include my Easywoodtool scraper in this test because quite simply it does not cut as clean. It did at first but after just very little use it won't cut nearly as clean as my flat scaper with a fresh burr. And I do mean very little use, mayby one bowl and few quick cuts to show students how it works.