Convex Sharpening Esee 6 Blade

[Rbpwrd240]

Hi all,

I am getting an Esee 6 while I tame my need for a Leuku Puukko Combo.

My question is how obtuse do you guys go with a convex edge before it isnt much more productive then a straight edge blade? I want to convex the 6 but I dont want to loose a bunch of the coating on the blade since I will always be using it around water. This means I will have a fairly obtuse convex grind.

Anyone have pics of their succesful convexing of the Esee knives over sand paper and mouse pad/leather while keeping the angle pretty large? Also if you did do it like this was the edge even any better at that large of an angle?

I have seen the following videos.

I would like to keep alot more coating then this.
https://www.youtube.com/watch?v=kMPCUH_acXM


About like this but I think this was done on a Belt Sander in Mother Russia.
https://www.youtube.com/watch?v=p-u8q86MghY

Thanks in advance,
Alex R.

 

[HeavyHanded]

As long as you do not increase the existing inclusive edge angle, any convexing you do will yield some benefit, esp for hard chopping. There is going to be a limit to how much convex you can grind into thicker stock at a given angle before it turns into a full flat grind. I do not know what the stock thickness is, or the factory edge is set at, but I would recommend lowering it to 30* inclusive, grind off the shoulder and smooth out the transition points between the primary grind and the new terminal cutting angle. I would imagine needing to remove the first 1/4" - 3/8" or coating, no less and maybe closer to 1/2" or more.

The further back up the primary grind face you go, the better the performance on deeper cuts and the thinner you can make the terminal cutting angle, but for potentially hard use I'd stop at 30* inclusive and remove however much stock is necessary to blend it in. IMHO, slight convexing at the primary/cutting bevel shoulder does not yield a lot of improvement - it takes a bit more stock removal to make it worth the conversion.

 

[Obsessed with Edges]

As long as you do not increase the existing inclusive edge angle, any convexing you do will yield some benefit, esp for hard chopping. There is going to be a limit to how much convex you can grind into thicker stock at a given angle before it turns into a full flat grind. I do not know what the stock thickness is, or the factory edge is set at, but I would recommend lowering it to 30* inclusive, grind off the shoulder and smooth out the transition points between the primary grind and the new terminal cutting angle. I would imagine needing to remove the first 1/4" - 3/8" or coating, no less and maybe closer to 1/2" or more.

The further back up the primary grind face you go, the better the performance on deeper cuts and the thinner you can make the terminal cutting angle, but for potentially hard use I'd stop at 30* inclusive and remove however much stock is necessary to blend it in. IMHO, slight convexing at the primary/cutting bevel shoulder does not yield a lot of improvement - it takes a bit more stock removal to make it worth the conversion.

That's good advice, and is what I'd be inclined to do as well. I'd not worry at all about widening the apex angle in trying to save the coating on the blade; that would only be counter-productive in actual use. The knife will be much, much more useful with good cutting geometry, and that's what the 30° inclusive apex would bring for you, convex or not. As mentioned, rounding out the shoulders of the transition will yield benefits in chopping and in slicing tougher material; polishing the convexed transition will go even further, and cutting stuff like cardboard will start to get 'scary slick' in doing so. Finishing the uncoated portions to high-grit (2000+) and polishing will also help to reduce the effects of corrosion as well, so the loss of coating won't be that big a loss anyway. Additionally, regularly maintaining the convex on a strop with compound is always going to keep the uncoated portion cleaned up; rust never has a chance to take hold on a regularly-stropped convex.


David

 

[Rbpwrd240]

WOW GREAT INFO!!!

I had to google three different terms just to follow your statments. I am new here but I have been around knives most of my life. I had never heard the term inclusive to talk about knife anlges. It makes sense though.

So to make sure I have this correct. An inclusive angle of 30 degrees is equal to a 15 degree angle on each side of the blade.

I did a very obtuse convex grind on my CRKT Folts Minimalist. SOGFari Machet and Bear Grylls ultimate. All of them are atleast as sharp as they were for fine cutting such as slicing paper but now they are easy to touch up on the stone strop or sandpaper an they have better chopping power and hold their edges longer. I figured I could do the same on the Esee but its hard to go and reshape a brand new $120 blade that rocks out of the box. However if I can get away with a little more angle and still have the same strength while giving me better cutting power then the choice is easy.

I wouldnt be knocking the shoulders off I would be giving the knife a true convex edge.

I normally go down to 80 grit sand paper and I sand one side till I get a burr then switch sides. Once both sides have a burI will do about 3-6 passes to knock off the burr and even out the blade. Then Ill move on doubling the grit each time till Im up around 1000. I usualy go a while alternating strokes at 1000-1200 grit. Say maybe 20-50 on each side. After that I use the levensailor stroping compound and block to strop the knife into a nice polished edge. Never tried the mothers and cardboard before.

Afer doing all of that correctly I have never had a knife not grab on my nail, slice paper and shave my arm. Even cheap steels will do it for the first couple of cuts. I realy want to get some of the automotive 2000 grit paper and a 1500/3000 grit whetstone. I am also going to get some leather to replace the mouse pad I have been using.

For sharpening convexed edges in the field I took a clip board with a slim design clip and cut it down to fit 4.5"x5.5" squares of sandpaper and leather so I can do any touch ups necessary.

I found out the stock angle on an Esee is 40 degrees meaning 20 on each side correct? The blade stock is 3/16" thick 1095. So I should be able to go to about a 30 degree inclusive angle at about 15 degrees per side without risking damage to the blade? I also dont want to voide the Esee warrant.

Thanks again for all the help guys.
Alex R.

 

[Obsessed with Edges]

So to make sure I have this correct. An inclusive angle of 30 degrees is equal to a 15 degree angle on each side of the blade.

Correct. :thumbup:

I found out the stock angle on an Esee is 40 degrees meaning 20 on each side correct? The blade stock is 3/16" thick 1095. So I should be able to go to about a 30 degree inclusive angle at about 15 degrees per side without risking damage to the blade? I also dont want to voide the Esee warrant.

Also correct. :thumbup:
I wouldn't see any reason to worry about damaging the blade at 30° inclusive (15°/side). Most any decent blades should hold up well enough there. The gains you'll get in cutting performance will usually offset any minor loss of edge durability anyway. Also don't see any reason why your blade's warranty would be voided; this is all part of necessary maintenance, in sharpening it up and using it. Knife makers know each knife they sell is going to be 'tuned up' to the uses of the buyer, and thinning the edge grind is part of that, many times. There might be issues if one were to take it down to literally razor-thin geometry, then batoning with it and wondering why it breaks (???); but most sane knife users likely won't be doing that, we hope.


David