Lapp Puukko bevel

[JonnyP]

Hello.........Can someone please explain to me the secondary bevel on a lapp puukko as described here
http://www.bushcraftuk.co.uk/reviews/lapp_puukko.html

I find that the knife is not too good at cutting veg, it tends to tear its way through rather than cutting, so I am wondering if I remove the second bevel (whatever that is) it will cut better. Other than that I find the knife is excellent, so my other question is, if I remove the second bevel, will the knife not be so good in other ways. Please help as I like to use my favorite tool for just about everything............ Jon

 

[singteck]

Don't think removing the secondary bevel will help. I think your problem, as well as all of us when it comes to vegetables, is that the blade is too thick.

Anyway secondary bevel is the small little sharpened angle at the edge other then the main bevel. Hmmmmmm maybe a picture will help but i don't have one.

Sorry

singteck

 

[Lost_Patrol]

If you remove the secondary bevel, the knife will be sharper, but will be less durable. Whether this is a good idea or not depends on how you use your knife.

 

[JonnyP]

Don't think removing the secondary bevel will help. I think your problem, as well as all of us when it comes to vegetables, is that the blade is too thick.

Anyway secondary bevel is the small little sharpened angle at the edge other then the main bevel. Hmmmmmm maybe a picture will help but i don't have one.

Sorry

singteck

I still don't understand what is the second bevel...........Does anyone have a photo, or can explain...............Jon

 

[Lost_Patrol]

http://i30.photobucket.com/albums/c302/Lost_Patrol_252/0cf56ad1.jpg

The first picture is a single bevel, the second picture has a secondary bevel. Hope this helps

 

[JonnyP]

http://i30.photobucket.com/albums/c302/Lost_Patrol_252/0cf56ad1.jpg

The first picture is a single bevel, the second picture has a secondary bevel. Hope this helps

Hi Lost Patrol........Yes that does help me understand, thank you. But it does raise another point.........My puukko has not got an edge like that........Jon

 

[Lost_Patrol]

Hi Jon,
From the photo it looks like your knife has a tiny secondary bevel (microbevel). I should have explained that my sketch was not to scale.
The diagrams only show the blade closest to the edge - they do not include the flat part of the blade.
A single bevel runs right to the edge of the blade without a change of angle. A secondary bevel changes angle at the edge. This makes the angle of the edge less acute so it is not as sharp, but is less prone to damage due to its increased thickness.

Cheers,
Andy

Edit - here is a better sketch

 

[JonnyP]

Hi Jon,
From the photo it looks like your knife has a tiny secondary bevel (microbevel). I should have explained that my sketch was not to scale.
The diagrams only show the blade closest to the edge - they do not include the scandi, part of the blade.
A single bevel runs right to the edge of the blade without a change of angle. A secondary bevel changes angle at the edge. This makes the angle of the edge less acute so it is not as sharp, but is less prone to damage due to its increased thickness.

Cheers,
Andy

Edit - here is a better sketch

So you are saying that at the very edge of the knike is the second bevel. This is the 40 degree angle that it is sharpened to. How can this be removed. Sorry to sound like a muppet, but its probably one of those things where it is easier to be shown in the flesh............Jon

 

[Lost_Patrol]

Don't worry, you don't sound like a muppet - I have asked the same questions too.

The way to remove the secondary bevel is to lay the knife on a oilstone / waterstone with its main bevel resting flat on the stone, and grind away for a long time. Slowly the two faces of the main bevel will get closer, until eventually they meet. At this point, your secondary bevel will be gone, and you will have a knife with a single bevel. Its quite a long job, but some people think its worth it. I have single and secondary bevel knives, and while the single bevels are great for impressing people, they are harder work to maintain. If you are cutting lighter materials, a single bevel will fly through them with impressive ease, but if you are cutting heavier stuff, you will be constantly resharpening.
Horses for courses

 

[JonnyP]

Thanks for your help on this Andy. The knife is plenty sharp as it is and I cannot imagine it would get sharper (I use a spyderco sharpener). So I think that I will leave it be so it will hold the edge it has for longer. Maybe I will buy another and remove the second bevel on that, so I can compare................Jon

 

[Lost_Patrol]

Jon,
If you are happy with the cutting ability of your knife then you are right to leave it as it is. You would only increase the sharpening workload.

If you do decide to go for a single bevel, it would probably be easier to buy a knife that already has a single bevel than grind away a secondary.

Cheers,
Andy

 

[baggins]

Alright Jon,
i've got a lapp pukko, looks the same as yours. i spent a good few hours removing the secondary bevel (like it says in the review). i have to say that after the initial faff of removing it, it is alot easier to sharpen and carves wood and cuts veg very well (you just have to cut down on the stropping if you are preping veg so as to leave a bit of a rougher edge on it). However, i have found that the edge is now very prone to damage if i'm not careful (mines a stainless steal blade, i'm not sure if the carbon is any better).
The pukko is a superb knife, the blade is thin enough for fine work but strong enough to take alot of abuse. Experience will teach you what type of bevel you will prefer (all my home made ones have a single bevel, but thats me).
Good luck with it and hope this helps

 

[JonnyP]

Thanks for your help Chaps, like I say, I think I will probably get another knife and remove the second bevel, just to see for myself how it will perform. I do find the knife very easy to sharpen anyway..............Jon

 

[Hoodoo]

If you don't want take the time to remove the secondary bevel completely but improve the slicing ability a bit, you might try convexing the edge. This can be done by gluing a piece of mousepad to a board and overlaying it with some wet/dry sandpaper. Then lay the knife almost flat on the sandpaper/mousepad combo, and pull it across in the direction opposite the edge. It won't take much to convex the edge on that knife so I would start with 200 grit or higher. You can do this on a stone if you know how to rock the blade while you are sharpening.

 

[JonnyP]

If you don't want take the time to remove the secondary bevel completely but improve the slicing ability a bit, you might try convexing the edge. This can be done by gluing a piece of mousepad to a board and overlaying it with some wet/dry sandpaper. Then lay the knife almost flat on the sandpaper/mousepad combo, and pull it across in the direction opposite the edge. It won't take much to convex the edge on that knife so I would start with 200 grit or higher. You can do this on a stone if you know how to rock the blade while you are sharpening.

That sounds even more complicated than removing the bevel. I just placed the knife over a stone and looked at how to go about rocking it to create a convexed shape and I do not feel at all confident to do this. I think if I started, the knife would end up more serrated than convexed. I do like the idea though..........Jon

 

[Hoodoo]

It was just a thought.

 

[addyb]

I don't think using a "Hoodoo Stone" is complicated, not in the least bit.

I used to have to sharpen my favourite SAK quite frequently. Out of the box, SAK's are a flat grind, and I used to sharpen them to a razor. But of course, they always dulled easily due to the thinness of the edge.

I later tought myself now to convex a blade by working on a defunct Shrade Old Timer until I got the hang of it, and then used my mad skills on all the SAK's in my house. (5 of them) It's an addiction, I swear!

Anyway, the end result is now my edge retention on a knife of only moderate HRC (56 is not too soft, but not too hard either) is that it has gone through the roof. I find that I don't have to sharpen my usual SAK hardly at all. And the real genius of putting a convex grind on a small knife, is that when I'm out in the bush, I can easily touch up the edge with a small square of mousepad and some wet/dry paper that I shall have inside of a zip-loc bag.

Hoodoo, :You_Rock_

Adam