Sharpening HSS

I have been turning thread bobbins from solid blocks of maple and oak. Often the shavings are like long (hundreds of feet) strips of paper. This is the result of using very sharp tools. I do not see many wood turners use tools that produce those fine, continous ribbons of wood. Very sharp tools make the job much easier and faster.

Often, in the past,  I wanted to make specialized lathe tools, so I would buy inexpensive sets of  tools, use a couple of them to make the  tools that I wanted, leaving me with several medium quality tools of ordinary design.  I often use these spare turning chisels for anything that  does not require a very  high level of craftsmanship - such as singles bobbins. I grind these  to the same angles as my other higher grade tools and I use them for things like singles bobbins. Yes, I have to sharpen these inexpensive lathe chisels more frequently than my higher quality tools, but that is perhaps honing them with 400 grit paper every 45 minutes rather than every hour.  With a good grinder, honing takes only half a minute, and is not a big deal.  In contrast, for very high precision cuts, I will hone my best tools with a diamond hone by hand every few minutes.

I still have some carbon steel lathe tools with sentimental value, but I do not use them much.  In theory, they can be sharper and produce a better cut than even my best HSS.  In practice, they do not.  To produce the quality of cut that I get with my good HSS tools, I would have to hone the carbon steel tools almost continuously.

Beginners or Experts?

Who should I make tools for?

I have always made the tools that I like. Some of my first needles were polished like jewels. They were slippery and I found them unpleasant to use. So early on I found that annular striations around the tip facilitated a gansey needle pulling a loop of yarn through a stitch. This made it easy for me to learn to use gansey needles with a knitting sheath.

Over the last few years I have become a better knitter. I can now use gansey needles with highly polished tips.

Last night, I picked up a set of the old gansey needles with the annular striations around the tip. I happily used those needles to knit a gansey in 9 days a few years ago, but now I find that I can knit faster without the   annular striations. This morning, those needle tips are smooth and polished. A beginner would find them hard or impossible to use. If I had been presented with those polished needle tips when I was beginning, I would have given up in despair  However, now I want something faster.

When one is making specialized tools, how does one compromise the needs of the beginner with the needs of the expert?

Makers of wood turning tools have a similar dilemma.  Wood is abrasive, and even the best wood turning tools have to be resharpened frequently.  Does one tell one's (new) customers how to get the best professional edge, or do you tell them they can do a "good enough" job of sharpening with a bench grinder?

Robert Sorby stands up and says, "This is how we recommend that our tools be sharpened."  It is an approach that requires a large capital investment, but results in a very high quality edge, saves tool material, and saves time.  Hamlet on the other hand, declines to make a definitive statement about how to sharpen Hamlet tools, and mumbles something about bench grinders being "good enough", fast, and inexpensive.  I feel sorry for owners of Hamlet tools that are not informed as to the best practice for sharpening HSS.

In wood turning, the burr raised by a bench grinder is ephemeral and will quickly be worn away by the wood it is cutting.

Any burr that can be raised  on a HSS scraper edge with a manual burnisher is ephemeral and will quickly be worn away by the wood it is cutting.  The cutting edge of a HSS scraper edge with a burr raised by a manual burnisher is not as sharp as a HSS scraper cutting edge honed with a diamond card.  This is a combination of tool engineering, metallurgy, and physics. I am amazed that people that would rather work with dull(er) tools than admit that I am correct.

Yes, it takes longer to sharpen a wood turning tool with a fine, slow speed, wet grinder, but the cutting edge lasts much longer than the cutting edge produced with a bench grinder.  So the slower sharpening system actually saves time in the course of a full day of high end wood turning. And since less tool material is removed, the very expensive turning tools last longer.  Thus, over all the system is less expensive.  The even more capital intensive Sorby system removes even less of the wood turning tool, and thus for somebody doing a lot of wood turning, the Sorby approach is even less expensive, because the big cost in wood turning is the cost of the wood turning tools that are ground away in sharpening.

Wood turning tools do not need to be hollow ground.  In fact, flat ground bevels are less likely to catch, and stronger. And, flat wood turning chisels with flat bevels last longer.

On the other hand, a bench grinder will very quickly produce a reasonable edge. And just as quickly, it will grind that expensive HSS into a pile of worthless gray powder.  Then, Hamlet can sell another set of  expensive HSS tools.