One Bevel, Two Bevels, Three Bevels, More?

[MMUK]

Not wishing to hijack other threads, I'm curious as the the advantages/disadvantages of having differing numbers of bevels on your blades. I've only ever honed a single bevel on my plane irons and chisels and find it works for me. So, why are there variations? How does it make a difference to performance?

 

[Random Orbital Bob]

a secondary bevel of say 30 deg on a 25 deg plane iron just means you only have to hone a tiny strip of metal next time you sharpen. Just saves time cos less metal

 

[MMUK]

I guess that's the Yorkshire way then? :lol:

 

[Random Orbital Bob]

Although born in Rotherham.....there is some Scottish in the family

 

[bugbear]

a secondary bevel of say 30 deg on a 25 deg plane iron just means you only have to hone a tiny strip of metal next time you sharpen. Just saves time cos less metal

Yeah - grind at 25, sharpen at 30. This is an old, OLD, technique.


BugBear

 

[Jacob]

a secondary bevel of say 30 deg on a 25 deg plane iron just means you only have to hone a tiny strip of metal next time you sharpen. Just saves time cos less metal

Yeah - grind at 25, sharpen at 30. This is an old, OLD, technique.


BugBear

It's the basic text-book default technique and is a good starting point. It tends not to be strictly followed but any system which leaves a sharp edge at about 30º will do, except hollow grinding isn't ideal for tools which get used forcefully.

 

[Corneel]

Honing on your final polishing stone is an inherent slow proces of course, so it is not a bad idea to only hone the very little bit at the edge. The rest of the bevel doesn't need to be polished. So it speeds up the total sharpening procedure. But there is a caveat (as always). On the next sharpening, when you want to raise a wire edge again, you must remove this secondairy bevel with a coarser stone, which takes time. So the net savings aren't as huge as you first think. Still, honing only the secundairy bevel makes sure that you are absolutely sure that you are honing the very edge, not an area a little higher up the bevel.

 

[Bigdanny]

(hammer) Is this yet another sharpening thread. (hammer)

 

[Random Orbital Bob]

Oh no it isn't....Look behind you etc etc ;-)

 

[MMUK]

(hammer) Is this yet another sharpening thread. (hammer)

No, God forbid :shock:

I was just curious as to why the differing number of bevels. I have what appears to be a reliable answer now so I don't see the need to turn this into War and Peace :lol:

 

[DTR]

The theory behind honing a secondary bevel makes sense, but I've seen some people advocate honing a third bevel. I just can't get my head around that. Anyone have an opinion on that?

 

[bugbear]

The theory behind honing a secondary bevel makes sense, but I've seen some people advocate honing a third bevel. I just can't get my head around that. Anyone have an opinion on that?

It just the concept of using a coarser grit, at a lower angle, to reduce the size of the metal worked by a finer grit at a steeper angle.

One could (in theory) extend this to any number of grits/angles.

I just use two; coarse grit at 25, all other grits at 30 degrees, on a secondary I keep well below 2mm.

BugBear

 

[DTR]

The theory behind honing a secondary bevel makes sense, but I've seen some people advocate honing a third bevel. I just can't get my head around that. Anyone have an opinion on that?

It just the concept of using a coarser grit, at a lower angle, to reduce the size of the metal worked by a finer grit at a steeper angle.

One could (in theory) extend this to any number of grits/angles.

I just use two; coarse grit at 25, all other grits at 30 degrees, on a secondary I keep well below 2mm.

BugBear

That's precisely my point, the secondary is so small that there is no benefit in honing an insignificantly smaller third bevel.

 

[Trafalgar]

Not wishing to hijack other threads, I'm curious as the the advantages/disadvantages of having differing numbers of bevels on your blades. I've only ever honed a single bevel on my plane irons and chisels and find it works for me. So, why are there variations? How does it make a difference to performance?

The reality of grinding at 25* and honing at 30* is that often in the heat of battle with lots of quick rehonings the 30* angle grows and becomes multiple bevels to boot - sort of a mess as anybody who has every bought a vintage tool can surely attest to. One lifts ever so slightly higher at each rehoning in order to produce a burr in a hurry. You can just go ahead and round it under and you'll save time and steel in the long run. This is the Paul Sellers/Jacob Butler/many past woodworkers lost to history technique. Or, alternatively, hone it on the grinding bevel with no lift - grind it at 30* and register the hollow ground edge to the stone and do not lift to put a micro on it at all. Everything happens at 30*

 

[MIGNAL]

I could resharpen several times on an 8,000G waterstone before I had to regrind the primary bevel. It most certainly is a time saver, although we are hardly referring to huge amounts of time. Perhaps 30 seconds here and there.
I think the advantage of the two bevels are that you can quite easily get away with having just two grades of stones, a very coarse one and a very fine stone. As I stated on the other thread, for a number of years I simply used a hand crank and the 8,000G waterstone. It's a pretty simple and relatively low cost approach, as you also have the tool to grind out some serious nicks. The slight disadvantage is the hollow grind on the hand crank. Perhaps more of a disadvantage if you are hitting Chisels, less so with Plane blades. Using a coarse flat diamond stone (or alternative) and that disadvantage disappears.

 

[dunbarhamlin]

The mortise chisel is an exception, where the shallow (20°) primary bevel has a rôle in the working performance of the tool by easing penetration.

 

[Jacob]

Hmm. :lol:
Mortice chisel best as rounded bevel IMHO. In fact essential. It's about leverage at the bottom of blind mortices. The rounded bevel makes for a moving fulcrum - as with many other levering tools; claw hammer, wrecking bar, nail puller etc.
It's deja vu all over again - this is where I came in burbling about rounded bevels several years ago. I found out how easy it is to sharpen rounded bevel mortice chisels and realised it was the same for most (all?) other edge tools.

To answer OP's question - the number of bevels doesn't matter in the slightest, it's just different ways of removing metal so you can get to a 30º edge. Except heavily used tools are better with one bevel (or close), for strength and resistance to vibration etc.

 

[dunbarhamlin]

Hehehe. Rum pipper. Though, must admit I do soften the elbow between primary and shaft by dipping at the end of the stroke.

 

[GLFaria]

I suppose most everybody here knows (and went through...) Brent Breach's Pages?

http://www3.telus.net/BrentBeach/Sharpen/index.html

More than one could ask for (certainly much more than I ask for...), but he has some interesting reasonings for the use of multiple bevels.

 

[Vann]

The theory behind honing a secondary bevel makes sense, but I've seen some people advocate honing a third bevel.

Coarse, Medium, & Fine?

Is this yet another sharpening thread.

'fraid so - or looks like it to me (hammer)

Cheers, Vann