Thank you for those who have contributed since my last post.
Woodturning can be broken down into perhaps 20 to 30 techniques. Their subjects are: tools their design and sharpening, and the choice and use of tools and other equipment in different turning situations. Richard Findley is correct that the separation into individual techniques is simpler for spindle turning.
So the first question is: can woodturning be separated into individual techniques? If it can then these techniques can be studied and compared with the alternatives. If woodturning teachers and other interested turners collaborate, then a consensus can be achieved. It is likely that for some techniques there may be more than one optimum, or that there is an optimum range.
What we have at present is the belief that different techniques suit different turners. Yet no-one has been able to define what innate factors determine that alternative A suits some, and alternatives B, C, and D suit different others.
We have discussed the sharpening angle of roughing gouges as a technique because it's simple and can be quantified. Look at Bill Blasic's last post. He is a much lauded and experienced turner. He wrote: "You are 1 of 1 and your optimum choice is 1 of 1. Where I stand is that your 30° angle is wrong, it is weak and it will not stand up to the test of time! Now that's me 1 of 1 and my choice is 1 of 1. End of back and forth, nothing to learn here."
I answered that I am not "1 of 1", that Dale Nish and Ernie Conover and I assume most of their hundreds of students also use 30 degrees. But the authors of about 15 other woodturning books promote 45 degrees. Bill Blasic reveals that he's never tried 30 degrees, and I suspect that the authors who promote 45 degrees haven't either. Is that responsible? Don't attack the messenger, do the trials and thinking.
I have taught many, and explain that I teach what I believe are currently the optimum techniques known. In my most recent class were three middle-aged women. They weren't put off the rigor of my teaching. This was an attraction because they could be proud of gaining strong skills in an efficient way.
Another example, Richard Findley wrote: "the overhand grip is, for me, optimal and the tied underhand is very much sub-optimal". Although invented in the 1920s, the grip was unknown outside NSW until probably the 1980s. Look in Richard Raffan's second edition of Turning Wood. He promotes the tied-underhand grip, although he didn't use it in England. Why? Because I showed it to him, and he realised its advantages. So I suggest that if Richard Findley gave it a proper trial he'd change his mind.
Richard Findley again wrote: "When it comes to bevel angles, I suggest people experiment and find what works, the most important thing is having a sharp tool, the actual bevel angle is very much secondary and having seen the state of many hobbyists tools I would suggest that the first step is to get them sharpening well and to a good profile before insisting on a particular angle. Indeed, some of the finest turners I know couldn’t tell you the angle they grind any of their tools to. I also don’t know of a single production turner here in the UK (and I know most of them very well) that hone their tools, they use them straight from the grinder."
Because I teach (I also ran a turning business employing six professional turners) I have to specify sharpening angles. I've also developed methods to grind those angles quickly and exactly. That production turners in UK don't hone is because they don't fully understand blunting and sharpening. A ground edge is serrated. The smaller the sharpening angle the longer the serrations, and the more readily they crumble off leaving a blunt edge. Honing removes those long, weak serrations leaving an edge which doesn't crumble. It therefore blunts slowly by abrasion. It's also very quick to resharpen by honing. If you grind a coarse angle the serrations are smaller and more durable. There's less reason to hone.
Are small sharpening angles desirable? I use 25-degree sharpening angles on the gouges I use on the outsides of bowls, on the inside of bowl rims, and on the ring tools I use in the bottom of bowl insides. Why because I don't sand most of the bowls I produce. Another situation, you have to turn a pair of adjacent beads. The angle at the bottom of the cusp between them is zero degrees. You can use a gouge, but the profile angle (Mike O'Donnell's term) is 50 degrees or more, so your beads would look dreadful. Therefore use a chisel. Book published before 1957 all have sharpening angles of about 25 degrees. Then Frank Pain promotes 45, and starts a fashion which persists to this day for unnecessarily coarse sharpening angles. Before 1957 the tool were produced from steel greatly inferior to today's. Sharpening angles should have gone down not up! So if you roll the two beads with a 25-degree sharpening angle, the beads will be near-semicircular. Use the much larger angles, and the beads will resemble inverted vees. So for this specific application, small sharpening angles are desirable. It turns out that if you grind and hone to 25 degrees the edge doesn't crumble, and because it blunts only by abrasion it blunts slowly, more slowly that a coarser edge. Therefore you can use it for planing, cutting fillets, V-cutting, etc. One of the finest turners I've ever seen honed with black Arkansas!
Richard also wrote: "What Mike doesn’t seem to appreciate is that there aren’t many production turners about these days and most turners do it purely for their own enjoyment so if it takes them all day to make a 12” bowl, so be it. Efficiency doesn’t really come into it, as long as they’ve had a nice time and made something they are pleased with and done it safely, then that’s a successful day." However imagine if a beginner was offered two choices: 1. you'll spend 40 hours of concentrated instruction and practice learning the basic optimum techniques, or 2 you can spend weeks stuffing around and thus learn lots of inferior techniques. I bet most will go for option 1. It's criminal that because of the anything -goes approach those who want to turn well don't have the option.
I am a highly qualified engineer. In my thirties I undertook the three-year trade course in woodturning at Sydney Technical College. This involved about 1,000 hours of tuition by professional turners. The course had been running since WW1. As those who have read some of my writings, or been taught by me will, I hope, attest, I try to produce sound information AND explanation.
If you contact all the fine turners in NSW, you'll find they all hone. However, the important thing is why hone. I have explained at length in my latest book why hone, and how to sharpen optimally. That many turners have closed minds is their loss.
I have suggested a simple 10-minute test: compare a 25 or 30 honed edge with a 45 degree edge, and report the results. No-one has taken up the challenge.
I realise that in USA no-one will want to adopt the techniques promoted by me in rural Australia. Be comforted that the techniques I promote were in the main invented by others. Only if there is agreement that there are optimum techniques will there be collaboration and a consensus on what those techniques are. If those I currently promote are found to be inferior, I'll change them. So, can we have some more definite inputs?
