While there are many ways to do those three steps I'm going to limit myself to three major types of sharpening "stones" with a couple of subsets. The first division is between natural stones and man made or synthetic stones and those two can be farther divided by what substance is used to remove swarf, either oil or water. There are many natural stones but I will limit this to Arkansas oil stones and Japanese natural waterstones. The synthetic stones for my purpose can also be divided into Norton India stones and Water Stones mostly from Japan. The Water Stones come in a mind numbing number of substrates and grits.
Some of my JNATs:
Notice the shop safety toes at the bottom of the image. The stone on the left side is a soft stone that is good for honing. The stone on the right side is the hardest and can give a fine polish. The four stones in the middle are all mid level hard and very good polishing stones that leave a kasumi (hazy) finish.
Because in today's woodworking world synthetic waterstones are the most used we have come to think in terms of the stones "grit". That is the wrong way to look at natural stones. For Arkansas oil stones the Specific Gravity, how dense is the stone will, within a general range, tell you if the stone is good for honing or polishing. Another factor that makes choosing a Arkansas stone easier is they all come from the same geological formation and a soft Arkansas is pretty much like any other soft Arkansas. For JNATs it ain't that simple. They come from many geological formations each different but whatever the mine, the stones hardness will help determine its best use.
The simple fact that there is not a "grit" classification with JNATs is the first major hurdle to learning to buy and use. Another is because they are natural stones, each stone is different, much more so than Arkansas stones. The only way to find if stone works for you is to learn and use the stone. There is the potential for kissing a lot of frogs if you do not work with a dealer you can trust.
All this begs the question; why bother. To answer I have to get into the weeds of polishing, what is the difference between the cutting edge of a natural stone polished cutter and one polished with synthetic Water Stones.
In the end there could still be the question; why bother?
More next time or whenever the mood strikes.
ken
Just curious about this Ken - do you use secondary bevels? Any thoughts on why if you do and why not if you don't?
ReplyDeleteRalph,
ReplyDeleteNo secondary or other bevels.One of the reasons is it is just better in the long run with less need for heavy grinding. Another important reason is a properly honed and polished Japanese chisel or plane iron has only one bevel and I use a lot of Japanese chisels.
ken
Hi Ken - IF one were to embark on yet another woodworking journey/rabbit hole, how to begin? I have long had an interest in trying JNAT's, but am totally at a loss as to how to find a reputable dealer. I have my trusted and goto folks for all tools western, but don't really want to drop good dough on crap. And how to start gradually after trusting someone. Continue using manmade stones and do the final polish on a hard JNAT, or vice-versa?
ReplyDeleteDealer recommendations???
Thanks,
festus (your neighbor in New Mexico)
Festus,
DeleteI've had good luck with https://www.japanesenaturalstones.com/ . I've also used So but he is almost impossible to contact. JNS is not a bargain dealer but he is reasonable.
The strength of JNATs is in the polish stage, in reality you only need one stone but they are kinda like potato chips, you have a hard time just eating one.
Look for something like this stone: https://www.japanesenaturalstones.com/ohira-range-suita-lv-3-5-a2048/ it is a little big and near perfect shape so not cheep but you can find smaller ones that are irregular shape such as short or broken cornors and the price goes way down.
As an example my normal stone progression for say a chisel that is not damaged but has been used and needs sharpening. Is to grind past the "wear" on both bevel and back with a Medium India, then hone on either a Lilly White Washita and/or a Norton Hard White Arkansas before going to a medium hard (around Lv 3.5) JNAT polishing stone.
Good luck, it is a fun journey,
ken
P.S. Like I said you can't just eat one. That Suita is on its way to Tucson. It is a sickness.
Those soft stones must be really soft.
ReplyDeleteDo you put shoes on if you are working with a hard stone?
Steve,
ReplyDeleteWhen I'm really working in the shop I wear "safety sandals". Have not lost a toe yet but there is always a first time :-).
ken
Agree on uselessness of secondary bevels.
ReplyDeleteRalph,
DeleteI can understand why guys like Cosman push them, for a single sharpening or even a couple they can save a little time and make the guy selling the video or course look good. In the long run you are better off learning to sharpen free hand.
Just my two pennies but then what do I know,
ken
Veritas has an eccentric on the guide wheel that only adds a very small change in angle. The angle change is smaller than what hand sharpening can achieve on a thin blade. Japanese blades are different because they are easier to register but still easy to dub to the edges.
ReplyDeleteIf you can freehand a bevel and read a reflection of print with no distortion up the the sharp edge, you have achieved zero secondary bevel. If the print starts to curve near the edge, it's because of a curvature and is equivalent to a secondary bevel.
If you look at a factory sharp Veritas plane iron they do use secondary bevel on only the very end of the bevel. That saves time and wear on the stone.
It's not an all or nothing proposition. If I am sharpening a Japanese tool, no secondary. Stanley plane iron, no problem. Either hand sharpen and get the default steepening at the edge or in the jig, I'll use the eccentric to concentrate the sharpening at the edge. Once it gets to be too wide on the secondary I can spend a not so short time on a coarse stone to reset the bevel if it matters.
Each approach has its place. I will say that switching back and forth between jig and hand sharpening on the same blade is for the birds because the jig has to correct all the inaccuracy of the hand work. When I am trying to make something, it's never iron dust.
Steve,
ReplyDeleteI have (I think it is still in one of the cabinets) and have used the Veritas guide. Way more trouble than it is worth.
The chisel standing on its bevel by structure is also a pretty good test. If done correctly hand sharpening will give you a flatter bevel than a jig for no other reason than with a jig as the cutter shortens the angle changes, that is if you want to get in the weeds :-).
You are correct, pick one and use it.
ken
If you want a stone polishing sydney in your kitchen, you can hire a Sydney stone polishing specialist. The Sydney stone polishing specialist will take care of every detail, from checking whether your walls and floors will not be affected and using water-based products to make sure that no dust is created.
ReplyDelete