Convex bevel troubles

[Steven Mikes]

I was attempting to follow Paul Seller's sharpening method which results in a convex bevel on the plane blade. I think what ended up happening in my case is that with repeated sharpening I inadvertently increased the curvature of the convex a little bit each time. It got to a point where I could reach the edge of the blade anymore without increasing the angle excessively. Now I'm trying to grid it back flat using a honing guide and it's taking forever . Is there a trick to avoid this?

[James Pallas]

Hello Steven, I learned to sharpen in this fashion. I have to say I no longer do it. It works fine. There is some muscle memory involved. You must keep it in mind to never go past your angle on the high side. Your brain will try to tell you to reach up to get to that edge, don't do it. On the low side it won't make much difference. My guess is your mind is tricking you and you are getting the typical result. The only way to fix it is to remove steel. Maybe after that chore it will help you to remember. I hollow grind and side sharpen nowadays.
Jim

[Robert Hazelwood]

You could make yourself a reference block. Take a 3/4" thick section of scrap, about 3" long and 2" wide or so. Take a protractor set to your desired edge angle, say 30 degrees, and mark the angle on a face, starting from the middle of the reference edge and going up towards one end. Cut to the line, removing the triangle-shaped offcut, pare/plane to the line if necessary. Now you can set the reference edge on top of your stone, and one end of the block will be angled up from the stone at 30 degrees. Hold the chisel up to that end to see and feel what a 30 degree angle is. Now you can remove the block and sharpen. You can repeat this as often as you need to during the sharpening process until you are confident about the angle.

[Andrew Pitonyak]

Send it to me, I will send it back sharp with a concave bevel so that is is easier to freehand.

I assume that you are free handing, right? Indeed you are correct that this is common when you free hand. I have no real advice there. I almost always use something mechanical to hold it in place unless I put a concave bevel on it at which point it is easy to free hand. I think that Rob Cosman sells something with magnets that holds the blade at a specific angle, which might help improving your free hand. I vaguely remember hearing, however, that this is common to see on older blades (convex edge).

[Bob Leistner]

I only run into that situation when I'm too lazy to go back to a very coarse grit and work back the bevel at least every other sharpening. If you habitually go back to 300-320 grit you shouldn't have as much trouble.

[Patrick Chase]

I only run into that situation when I'm too lazy to go back to a very coarse grit and work back the bevel at least every other sharpening. If you habitually go back to 300-320 grit you shouldn't have as much trouble.

Or just get a flat-disc sharpener (WorkSharp, Veritas, or one of the knockoffs) and use that to flatten the bevel every so often.

[Warren Mickley]

I think you are following horrible advice. It is as if Sellers had trouble keeping a flat bevel and so pretended it did not matter. If you look at this picture of Sellers' chisels, you can see he is having the same problem as you; he is sharpening at about 45 degrees. If you watch his videos he says it is about 30 degrees, but it quite obviously is nearer to 45. You will have the most control and consistency if you use a flat bevel.
sellers chisel 2012.jpg

[Bob Leistner]

Yikes, I had no idea that is Mr Sellers idea of convex. Mine end up a bit convex but I don't think I would try to end up like his. I do occasionally put an edge to a gage, and I'm usually right around 30+/- a couple.

[bridger berdel]

a little convex is unlikely to cause problems. the tool will tell you when the edge is too steep. I am not shy about using the bench grinder to keep the heel of my chisels from getting too fat and the bevels from being too rounded.

[ken hatch]

a little convex is unlikely to cause problems. the tool will tell you when the edge is too steep. I am not shy about using the bench grinder to keep the heel of my chisels from getting too fat and the bevels from being too rounded.

Bridger,

What ever works, amirite . Like you I'm not afraid of a little convexity, the tool will tell you when it is time to grind.

ken

[Patrick Chase]

I think you are following horrible advice. It is as if Sellers had trouble keeping a flat bevel and so pretended it did not matter.

More like he had trouble keeping a flat bevel and so turned it into an exaggerated fetish.

Seriously, how do you "ride the bevel" with dramatic curvature like that?

[Stanley Covington]

I think you are following horrible advice. It is as if Sellers had trouble keeping a flat bevel and so pretended it did not matter. If you look at this picture of Sellers' chisels, you can see he is having the same problem as you; he is sharpening at about 45 degrees. If you watch his videos he says it is about 30 degrees, but it quite obviously is nearer to 45. You will have the most control and consistency if you use a flat bevel.
sellers chisel 2012.jpg

Amen.

Mr Seller's sharpening technique works for him, but it is not something to emulate. You can do better.

A rounded bevel has its uses, especially in the case of carving tools. But as Warren says, the flatter the better. Also, it is much quicker to resharpen a flat bevel than a rounded one because it is easier to find and then focus one's efforts on the extreme edge, which is what really matters. The time, effort, and stone mud spent making a rounded bevel is waste.

[Doug Hepler]

Steven,

Without knowing your setup and your comfort zone, it's hard to know what to recommend. If I had your problem (given my setup) I would hollow grind your convex bevels on a high speed dry grinder using a 60 grit white (ALO2) wheel. Then you can take the hollow ground edge to flat abrasives (stones or sandpaper). The hollow grind makes hand honing easy except for the narrowest chisels, when I use a jig (Veritas MKII). I used to use the jig more often but my skill in feeling the bevel has improved.

There was a day that I would never touch a good chisel or plane iron to a dry high speed grinder, but that was long ago when I had mostly carbon steel tools and a lot more patience. I learned HS grinding when I took up turning and was soon able to grind without overheating the edge. (dress the wheel, very light pressure, keep moving, quench often) I have re-shaped my share of edges by hand on a flat stone but that is just too tedious for me today. Modern HSS is fairly forgiving of overheating and too hard to shape by hand (IMO). If you have a HS grinder, go get an inexpensive chisel from the hardware store and practice grinding and honing it until you get some confidence.

I cannot understand/agree with Paul Sellers ideas on sharpening except that you should hone very lightly and very often. A hollow ground edge facilitates hand honing. When you press down on the very edge, you can feel the bevel "click" into the angle you need. Honing freehand facilitates frequent light honing. Also, if you want to hone by hand, it is easier to do if you use "trailing edge" honing, the opposite of what we were taught. When you are down to the finer grits, you can call it stropping on a stone if you like. Even if it creates a wire edge, we knock it off when we flip the tool over at the end.

Doug

[Mike Henderson]

Or just get a flat-disc sharpener (WorkSharp, Veritas, or one of the knockoffs) and use that to flatten the bevel every so often.

Yep, grind a 25 degree primary bevel and then put a micro bevel on to the angle you want - 30 or so degrees. Quick and easy. Do the secondary bevel freehand on a 8000 stone.

Mike

[Todd Stock]

I love a nice, long slightly convex bevel...on a carving chisel. For everything else, flat or concave and about 5 degrees less than I want to hone. What was he thinking, beyond keeping the subscription bucks rolling in?