To the hand sharpening hollow grinders. Just one question.

[DTBoss]

Been trying to simplify and speed up my sharpening routine. Thinking of ditching a jig.

To all of you who hollow grind your chisels and plane irons before hand sharpening (no jig), I have one question.

True or False. If you grind a primary bevel on a circular grinding wheel (6" or 8" or whatever) at 25*, then lay the iron bevel down on the stone and start honing, you're essentially honing at the same 25* you ground at.

The only reason it's only wearing away iron at the front and back of the bevel is due to the concavity of the grind. Yes?

If anyone thinks this is false, please explain as I don't currently see it this way.

Thanks,
Dan

 

[Ed Fasano]

While I do use a jig, except when an quick touch-up is needed quickly, I can still chime in a state that you are correct. The concave nature of an edge ground on a round wheel renders an surface that will, for a time, meet a flat stone surface (only) at its leading and trailing areas.

 

[Mike Davis]

Not sure I follow your question as I don't like to use negative questions.

I guess it depends on how you measure 25 degrees tangent to the wheel?

Anyway honing a bevel from from a hollow grind saves work because there is less steel to wear away. The stone cuts flat and the hollow doesn't touch the stone.

I haven't found a great difference in the cut from 22 to 27 degrees bevel on a Stanley bevel down plane. So I don't lose sleep over the angles on my plane blades even though I am slightly OCD. Some things simply don't matter.

 

[DTBoss]

Not sure I follow your question as I don't like to use negative questions.

I guess it depends on how you measure 25 degrees tangent to the wheel?

Anyway honing a bevel from from a hollow grind saves work because there is less steel to wear away. The stone cuts flat and the hollow doesn't touch the stone.

I haven't found a great difference in the cut from 22 to 27 degrees bevel on a Stanley bevel down plane. So I don't lose sleep over the angles on my plane blades even though I am slightly OCD. Some things simply don't matter.

Thanks Mike,
Sorry if I wasn't clear, but thanks for the useful info.
I suppose you're right about the 'depends'. I was assuming a hollow grind that would start at the midpoint of a flat unground primary bevel and grind it's way in until it covered the whole bevel surface.

You're also correct about not losing sleep over this stuff, which I'll stop doing.....soon!

 

[Mike Davis]

Sharp is much more important than a few degrees of angle one way or the other. Learn what sharp is and worry less about how to get there.

 

[danmart77]

Dan
I think you have it right in your first post. When I do hollow grind, I try to get close to the 25 degree bevel than its just a visual thing. As a rule I just take a black marker and run it across the edge and begin honing.

I might add: hollow grind or flat grind will only be as good as the flat polished bottom of the chisel. In my view, getting the bottom of the chisel is often overlooked and it makes a big difference over the long haul. I work the bottom back about an inch of two till its flat, smooth and it looks like a mirror its so polished. After that I don't fool with the bottom unless I damage it.

I have chisels for pounding with a mallet and some just for paring. I often grind the paring chisels to 20 degrees and they seem to hold up just fine if I don't use them with a mallet. My skew chisels would be a good example. I use them to get in dovetailing corners and clean up the corners.

In the photo its the one on the far right.

Dan

​

 

[walnutjerry]

Sharp is much more important than a few degrees of angle one way or the other. Learn what sharp is and worry less about how to get there.

I found out about "sharp" when I took the chairmaking class with Curtis Buchannan. The first six hours were spent sharpening my draw knife. Six hours of rubbing that drawknife on water stones, most of it on the back side of the knife until it was shining like a mirror. After that was done I honed the bevel with a diamond hone. Made as much difference as day and night using the draw knife. After honing we put a shallow hollow in the bevel about midway of the bevel to make honing quicker in the future. I have never done anything but hone the bevel with a diamond stick since.

Jerry

 

[danmart77]

Jerry
That makes perfect sense on the drawknife. For most things these days I use a flat grind but the drawknife just doesn't fit the Worksharp disk very well. Two choices: go to the wheel or use a belt sander for a flat grind. I know that Curtis likes his wheels and they are a good choice.

The drawknife in this case is being sharpened like a paring chisel I imagine with a relatively low angle as you are pulling it.

From working with him in the past, I recall he used drawknives with a double bevel and a single bevel. They both have their place.

Curtis uses the drawknife to a level well beyond what I work.

Going around sharp curves, I use a farrier's file to remove wood quickly then I have to go back with a radius bottomed spokeshave. I think I am just quicker with files from all my hours shaping curly maple gun stocks. The drawknife is not the tool for sculpting maple so I just carry that over to the pine as I am working the seat.

I would love to find more drawknives so I could bend the handles to fit my work. Its been slow finding the knives as I don't search the flea markets much these days. I just make due with the 2 knives on the wall.

You have been lucky learning from Curtis. I learned from the guy Curtis learned from on the Windsor stuff -- Dave Sawyer up in East Calais Vt. Over the years, I think Curtis has taken the Windsor building to a level never seen in the 18th century. His chairs are works of art.


Keep em' sharp
Dan

 

[Rwe2156]

I hollow grind at about 25 and sharpen at 30 so I'm only honing the front aspect of the bevel.

BTW, I also gave up on the jig and do all my hollow grinding by hand now. Tired of all that fiddling around. Its a Veritas jig.

I turn grinder on then off right away and lightly touching the iron to the wheel as its slowing down. Check the scratch marks and adjust til I get the middle.

 

[walnutjerry]

Jerry

You have been lucky learning from Curtis. I learned from the guy Curtis learned from on the Windsor stuff -- Dave Sawyer up in East Calais Vt. Over the years, I think Curtis has taken the Windsor building to a level never seen in the 18th century. His chairs are works of art.


Keep em' sharp
Dan

Dan,

I contacted Dave Sawyer before I took the workshop with Curtis. I would like to have been able to do a workshop with Dave but distance put a halt to it. I settled for a week with Curtis as a one on one workshop---do not regret the experience with him. Dave's advice was " I would be glad to work with you but you have a fine chair maker a lot closer to you, Curtis Buchannan."

Jerry

 

[danmart77]

Jerry
That response from Dave doesn't surprise me a bit. That is how I remember him. When I went to see him in his shop years ago, it was in the summer months. When it started to get a little warm in the afternoon, Dave wanted to take a short rest and left me to work in the shop or go out back and take swim in the pond.

Dave was primarily making ladderbacks and moving on to the windsor back then. The only guys in the business were Dave and Mike Dunbar as I recall. They were both doing things in a traditional way but I liked Dave's approach better.

The decision was easy between the two when I watched Dave turn his legs. They had "flare" to them. This is what I think is the distinguishing trademark of the current builders.

Curtis, Elia Bizzarri and Peter Galbert are a few of the full time instructors that I would point an interested enthusiast towards if they had a pocket full of money. Its a great way to learn the entire process. I'm sure there are others out there offering week long one of one courses but those are the guys that come to mind for a man with a burning desire to build traditional windsors.