Tom Wirsing will be the national turner for FLWT on Thursday Nov 16, 2017 and he will be the featured speaker for Rochester Woodworkers Society (RWS) on Friday Nov 17.
The following information describes the topics that Tom will cover at an all day (9am to 4pm) demonstration on Saturday Nov 18. You can register to attend the Saturday demonstration at a cost of $35 at Register for Events on the home page.
Improve Your Bowls and Platters with a Two-Step Turning Process
I am an advocate of a two-step turning process. I use my gouges to shape my platters and bowls, removing 99% of the wood. But before sanding, I scrape the entire surface of the woodturning. I consider scraping the first step in sanding, but the scraper is far more accurate and delicate than sandpaper, getting the surface of the woodturning “perfect” before sanding begins.
I advocate the use of Negative Rake Scrapers. The cutting edge of a negative rake scrapers is ground at around 22.5 degrees top and bottom so the nose of the scraper has an included angle of about 45 degrees. The scraper is held flat (horizontally) on the tool rest and is therefore exceptionally easy to control. The negative rake on the top of the grind, and the fact that the scraper is held level (horizontally) on the tool rest, means the scraper does not self-feed and therefore will not “catch”, and is exceedingly easy to use effectively. The burr on a negative rake scraper is the only thing which cuts smoothly, so the scraper must be sharpened (reground) frequently to refresh the burr. In use, the cutting edge of the scraper is ever-so-gently floated across the surface of the wood, removing every ripple, dimple, and every speck of tear-out, even on difficult, highly figured hardwoods. If the scraper must be pushed into the wood to get it to cut, it is dull and will do more damage than good. Very delicate scraping with the burr of a freshly sharpened scraper is the correct technique for excellent results.
In this demo I will turn a platter using the two-step turning process. I will review the process steps to turn a platter, and I will demonstrate the use of gouges to remove 99% of the wood, and the use of negative-rake-scrapers to perfectly prepare the surface of the wood before sanding.
If examined under a microscope, the cutting edge of a freshly sharpened negative rake scraper looks like very fine sandpaper, and it works like sandpaper, except that it can be used with much greater accuracy and delicacy, perfectly preparing the surface before sanding commences. It’s exceptionally easy to remove all irregularities, fine tune curves and shapes, and get that ”perfect” shape. If the turning isn’t “perfect” before sanding, sanding will not improve it. Get it right with the two-step turning process before sanding. You will be impressed with the results.
Current Technologies in Woodturning Tool Steels and Grinders – A Technology Update
There have been dramatic changes in the tool steels used in woodturning tools, and in the grinding wheels woodturners use to sharpen tools. These changes have produces confusion and misunderstandings about which steels are “best” and which types of grinding wheels work best with which steels.
M2 has been, for many years, the most successful and widely used high speed steel for woodturning tools. M2 is a “conventional” high speed steel. But in recent years CPM 10V, a particle metal steel, has gained wide acceptance. What is the difference between these steels, and why are these differences important? This demonstration will explain.
Grinding wheel technologies are also changing. For years most grinding wheels have been cast with a hard abrasive, typically aluminum oxide. Recent years have seen the emergence of steel wheels with Cubic Boron Nitride (CBN) bonded to the grinding surface. This demonstration will explain the difference between the two types of wheels, where each works best, and why.
During the demonstration I will grind both M2 and 10V tools with both conventional grinding wheels and with CBN wheels, examine the grinds with a 300 power digital microscope, display the images in real-time on a large-screen display, and discuss the differences in results. I will also turn some wood with each tool, assess performance of the different steels and grinds, then re-examine the grinds under the microscope to assess wear. I will leave ample time for questions and answers, a very important part of the learning process.
This demonstration also includes a PowerPoint presentation which explains why industry was compelled to create high speed steels and particle metal steels, the chemical composition of M2 and 10V and the importance of the various alloys in providing toughness, wearability and resistance to heat, the manufacturing process for each, with pictures depicting the process used to produce modern particle metal steels.