Scandi vs convex for bushcraft knives??

Boats said:
You got me there.:D

I suppose I should elaborate. I have examples of all five of the typically found grinds, (flat, hollow, chisel, scandi, and convex), and I find that the scandi grinds are more amenable to various sharpening devices than are full convexes.

In my experience, the best way to both sharpen and touch up a convex is through stropping, either with charged leather or with wet/dry sandpaper.

Scandis, at least those with only a primary bevel, can be stropped that way too. However, they are also very sharpenable with flat stones, and ceramic or steel rods. I have found that one has to pay far more attention to a convex, in order to not screw it up, when using any other method than stropping. Being able to swipe a DMT diafold over a scandi once or twice on each grit is better than trying to strop one's jeans or breaking out even an improvised sandpaper on cardboard strop.

Since scandis are more flexible in the way they can be rapidly sharpened, and since when done right they still feature the convex's best selling point, the zero degree edge, I give the nod to the Scandinavian grind for field use.

That said, a well executed flat grind is generally more versatile than either, especially for slicing through something as both scandis and convexed blades tend to wedge cut and so split things more than they slice through them.
Click to expand...

Glad you caught it! :D

I pretty much think teh same way about convex edges - except for the "sharpening devices" if you mean things like Lansky, EdgePro, Sharpmaker, etc. If you mean regular benchstones, etc, well, I've been doing shaving sharp convex edges freehand on stones for many years. I've got a knife I've been using for over 25 years, convexed, always been done on flat stones.

I got caught by the sharpening devices for a bit, then found Bark River knives, and Falkniven, and went back to what I knew. Convex edges aren't mystical, they just work, and have been what folks have actually had on their knives and swords since metal knives were invented.

Strops are great - I use them all the time. I also use a Harbor Freight 1x30 belt sander if I need to reprofile a knife, cuz it works so well, so quickly, and does such a great job.

I'm glad you like your Scandis - I like them too - as soon as I get a convex edge on them! :D: thumbup:
 
Thanks Stretch, I've got to get my head round this,just afraid of ruining the knife.
 
I was just having this conversation a couple of days ago with a knife maker named Bryan Breeden of Breeden Knives. He likes a full flat for everything knife related not chopping. Slicing through food is always better with a full flat and good for woodcraft type chores too. Scandi seems to be the only kind of grind I can make really sharp but it does have more drag through some kinds of food so I see where Bryan is coming from.
Check out a review of his knives. Full Flat Grind.
http://www.bladeforums.com/forums/showthread.php?t=547103
 
Really the only thing I see as being a benefit to a scandi grind and why they're popular with bushcraft knives is that like has been said before, a flat grind is better for wood work and scandi's have a flat rather than convex edge....and with a scandi, you can have a knife made from thin stock with a thin edge, but maintain a lot of stregnth by having that particular grind as you can keep the maximum amount of metal on the blade.
 
For a bush knife I'd vote for scandi ground because you can resharpen it with a small pocket stone. Convexed edges are easy to maintain, but require more equipment which makes it less practical in the field.

That being said if field sharpening wasnt an issue I prefer convex edges.
 
Well, I'm not sure which is easiest to sharpen in the field, but I will say this: for a couple fo touch-ups in the field, the convex edge can be sharpened on the stone just as you would a standard v-grind or Scandi. It wouldn;t take much, just a few very light strokes. When you got back, you could redo the convex edge the traditional way. Also, when in the field, you can strop the convex edge on the hone if you choose. I've read in here where some guys "strop" their convex edges on a stone anyway.

The same thing with a Scandi: you could just very slightly micro-bevel the edge as opposed to honing the whole primary grind, then do it right when you get home.

So........ I would say it could be a toss-up when it comes to sharpening.
 
Convex. And convex can be sharpened on a stone too with a "rolling" angle instead of the set angle used to sharpen the other grinds. It's pretty easy to do, but not as easy as the stropping.

Phil
 
I am a bushcraft guy and Whenever I do long periods of carving with several strops, The blade chips. With a convex, because you have a curved grind, the wood dosn't tighten up on the edge forcing you to push harder like on scandi grinds.
But I think personally that scandis are alot easier to sharpen.
If I had to choose a long term survival knife, if would be a convex barkie.
If I was going on a 3 day campout, I would bring a mora bushcraft knife.
 
i am constantly amazed at how scared people seem to be of convex edges.

afaik: anyone who's been freehand sharpening a knife on stones for any period of time probably has a convex edge whether they know it or not. my Leatherman has a convex edge, but not a "full convex grind".

IMHO: a convex edge is a lot easier to maintain than any kind of flat or hollow grind. a strop doesn't take up a lot of space or weight in my pack and here's a tidbit: you can retouch a convex edge on flat stones. it's just those rod-and-angle thingy doobers like a Sharpmaker that you can't use with a convex edge.

a full convex grind is a slightly different bucket of fish and requires the knifemaker to be on the ball. but once it's ground, they're easy to maintain.
 
I like a convex for general outdoor utility (carving, splitting, a little chopping, etc...) and a scandi exclusively for woodworking.
 
For me i like a scandi grind. The main use of my knifes are woodwork/bushcraft so it cuts better, plus they are soo easy to get razor sharp.

But I like a convex edge on bigger knifes, infact I'm thinking of putting one on my RTACKII.

I do like a convex edge on an axe though, they just work better.
 
Practically speaking, most scandi-ground knives end up with a convex bevel and that is when they become reliable (no edge rolling or chipping). I've reground so many scandis to zero grind convex blades and the improvement is stunning. Of course, the blade is thinner then, so it cuts better; but, the edge doesn't roll as easily. So, I have a tendency to roll my scandis which I want to retain their original grind, simply because it works better. Scandis are great, but they need some attention.
 
what base are you using between the wood and the sand paper?
StretchNM said:
Willgoy, don;t let it scare you. You have to just get your Barkie down on the sandpaper and do it. Here's a couple of pics and that's ALL you'll need:
convex-01.jpg


flip the boards over to this:
convex-02.jpg


-If your Barkie isn;t very dull and just needs to be touched up, start at 1500;
-Keep your angle low and your pressure light;
-some barkies require a slightly higher angle so adjust as you strop;
-do about 5 on one side then 5 on the other, then 5 and 5, and so on;
-I hold the strop (wet/dry board) in my left hand and strop with the right - this allows me to vary the angle and pressure;
-remember - very light pressure (very light) - some say no more than the weight of the blade (I use about that), some say if you think there's absolutely no way that any metal is being removed, then the pressure is about right;
-move to 2000 grit and strop about 3 or 5 per side as before;
- for the final passes, strop once per side for about 5 strokes (one side then the other for about 5 times);
-finish on a CrO2 loaded leather strop, using the same angle and pressure

It's easy and you'll get better and better as you go along. Go to the BRKCA site http://www.barkriverknives.com/home.html and click on "Sharpening the BRKT Way" on the right-hand side. It's easy - you'll see
Click to expand...
 
In my experience convex are easier to sharpen and they stay sharp much longer than "true" scandi (of which though I got only one, Wrights Bushcraft so my experience is limited). Besides, convex knives generally speaking cut better as lesser area of the blade stays in contact with the stuff being cut resulting in less friction. And while a 5mm thick blade cannot really be a "slicer" whatever the grind, a convex blade slices way better than a scandi.

I just did a small experiment, cutting and slicing an apple using the Wrights bushcraft mentioned above - 4.5mm thick blade, scandi ground, and my Bravo 1 - 5.5mm thick, convex ground. The convex wins hands down - I could actually make nice looking slices without particular effort. The scandi knife basically has to be worked like a chisel, it wants to cut not parallel to the main plane of the blade but rather along one of the edges. The convex even being 5.5mm thick cuts more or less like a normal knife. So my opinion is: scandi is marginally better for precise woodworking, convex is much better for everything else.
 
Easier to sharpen, or easier to keep sharp? The convex is easier to keep sharp because all you need is a strop. When it comes to sharpening in the field though, a scandi is easier to set the angle, but you have to remove a heck of a lot more steel. Technique, DMT Diafold and a strop is all you need to sharpen convex in the field, but you're a lot less likely to need to sharpen it in the first place.
 
Over the years I've become a big fan of convex blades and have converted most of my blades to this edge. Love how they hold an edge and once you get the hang if it are pretty easy to keep razor sharp. Have migrated from the wet/dry sandpaper over mouse pads to a Kalamazoo 1x42 belt sander. Still strop on the sandpaper occasionally when I need a little zen relaxation... :-)

Carry a small 2 sided strop in the field for touch-up and keep a bat strop in my truck should the need arise.
 
Scandi is great at home when using perfectly flat abrasives and when you have plenty of time. With a scandi you have to remove more steel than you do with a standard edge bevel. IMO scandi isn't as field-expedient as touted but YMMV.

Convex became easy to maintain once I got the hang of it. I use sanding belts in different grits and use them like strops to restore a very dull edge. You can also put stropping compound on the backside of a belt for fine touchups. Belts are lightweight and can be rolled up. Very portable. You could lay it on a flat solid surface to sharpen a scandi too.
 
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