How to sharpen lathe chisels

Anyone who has had a lathe for more than a week knows that you need to sharpen your chisels and sharpen then often.  Nothing dulls tool steel like a 3000rpm spinning chunk of wood.  I have recently gotten back into wood turning after a ten year break from it so I am revisiting my sharpening techniques and questioning them so what you see here is a combination of my old tradition with a few changes.

A quick google search will yield about ten million hits on jigs, techniques, systems, and machines for lathe tool sharpening.  The popular questions seem to be dry grinder vs slow speed water grinder, jigs vs free hand, and whether to use tools straight from the grinder or honing them a little.  It really comes down to the fact that there is no right or wrong way to sharpen your chisels and what works for a production turner might not be best for a hobbyist.  I used to be a run to the grinder and then straight back to the turning, it was quick enough for most chisels and seemed to work find.  The problem occurred when trying to use a jig for a fingernail grind gouge, it was just slow to change from a flat tool rest to the jigs needed for the gouge so I went searching for something else.

So what do you need....  Well you can start with sharpening stones, they are slow and you simply cannot regrind a profile on a bench stone, it is just too slow.  Other options are a bench grinder or belt sander, I currently have a bench grinder which works fine but takes up a lot of room in my small shop and takes forever to change to a different grit stone.  I am seriously considering getting rid of the grinder and using a small 1" X 30" belt sander but for now the grinder works fine.

My setup is:
1725 rpm 6" Baldor Grinder with 120 grit pink wheel
Wolvering Basic Grinding Jig  
Two sided diamond stone (course and fine)

Step 1 Sharpening the skew chisel

We will start talking a little bit about the flat chisels, the skew and scrapers.  These chisels will be sharpened using a flat tool rest.

Skew Chisel - The skew is used to produce a very fine finish on spindle turnings.  It is also a great too for creating beads on a spindle.  The skew is also a tough tool to master, it can produce some really impressive catches so be careful and spend some time practicing, it will be worth it.  I have included an image with the proper angles for the skew chisel.  The first step to getting a good edge is to establish your initial grind and we will do this on the grinder.  I start by putting my flat platform in front of the wheel and adjust the angle with the skew on it until I get that skew on the wheel near 25 degrees.  You can place marks on the platform at 70 degrees as a reference and to help you hold it straight.  You want to grind at this angle until you have reached both ends of your bevel.  You want the edge to meet in the middle of the tool thickness so this might take a little trial and error to get there.

Comments

[pfred2]

I have yet another reason for you to hate grinders.

You may not be aware of it but every time you mount a circular grinding wheel you should dress the wheel to true it up. They never quite run the same after being dismounted then remounted.

If you want your edges to last longer you should strop them. That stops the wire edge from bending over. If you can strop a wire off a sharpened edge then you know what you have is really sharp. I use leather charged with red rouge polish.

Another tip: put some super cleaner on your diamond hones for lubrication. Stuff like Super Clean by Castrol or Purple Power a knock off that is basically the same thing.

My sharpening routine goes grinder, synthetic diamonds, 4 grits, medium, then hard Arkansas stones, then stropping. Though once I have the geometry correct I don't usually grind anymore. I have Japanese water stones too but I don't use those for everything.

[friger]

Did you know that when turning the wire edge is what is doing the cutting? You don't need to strop a lathe chisel, the grinder is all you need. Call me wrong but I've spent too much time standing in wood curls to be mistaken about this. What you are doing is a fine job of making a carving chisel, and I would think you are an expert carver.

[jskingry]

Thanks for the comment friger. Those oysters you smoked look great too, gonna have to try that myself! Down here on the west coast of Florida we smoke a lot of a fish called mullet to make dips or just eat straight, maybe I will grab some oysters next time I fire up the smoker.

[pfred2]

When I lived in Florida we netted mullet for bait. I never knew you could eat the things!

[jskingry]

They make great bait, but some of us brave folk on the west coast eat them too.

[pfred2]

Yeah I lived on the east coast on the Indian River Drive so I had the Indian River in my front yard. Was nice, I had crabs for lunch just about every day. I used the mullet to bait the crab trap.

[pfred2]

I guess you like to scrape then.

[jskingry]

pfred,

I have the solution for dressing the wheel, I just don't remove it from the grinder ever. I do have a diamond dresser that I use from time to time to keep the face flat. I just didn't want to broach that subject since it is not directly related to the topic of lathe chisels and not being a metal worker I will leave grinder setup and maintenance to the true experts.

One of these days I might get around to stropping but the diamond is just so quick and easy and the edge the fine side leaves will not shave but it will pop hairs.For cleaning my diamond I just used dawn from time to time to clean it, seems to work ok and I like the stone dry so I can keep it in my pocket. I have water stones and oil stones too but I like the simplicity of this routine since I never have to leave the lathe I just pull the diamond stone out of my pocket a few quick swipes and I am ready to do my finishing cuts on the piece.

Now if I am sharpening a plane iron or a bench chisel I will go all the way to my 8000 grit water stone to make it shine, but that is another instructable.

Thanks for feedback.

[pfred2]

Oh you have a diamond dresser do you? One I made maybe?

http://www.jstool.com/wheel.htm

Before you ignore my suggestion maybe you should try it? Pretty good chance I know a thing or three more than you do about sharpening.