Obtuse angles on bushcraft / choppers, do you refine them as far as others?

[Cereal_killer]

I'm decent at freehand sharpening, I'm not an expert but I'm quite capiable. I have hair shaving edges on all my blades but I'm wondering if its really necessary on some of my dedicated choppers. Now I'm not talking about my Mora- to me that's an EDC style knife (and I do EDC it alot) so I have a 15DPS micro bevel on it cause that's what I like best and that's what's easiest to maintain for me with a strop.

What I'm specifically talkin about is my larger "chopper" style knives that I use for outdoors stuff- wood processing and cutting the occasional bone and that type of stuff. I keep those knives at a 25dps bevel for longer edge retention during hard use. Is it necessary to refine them as far? (the 2 I have are both 1095). Does it even provide any advantage vs. if I just stop after I've debured on my 1200grit DMT? For what I use it for do I really need to spend the time on my 2400grit ceramic stone and with my strop?

 

[HeavyHanded]

Just my opinion, but 50 degrees inclusive is so broad you're fighting yourself. A chopper made from steel with appropriate characteristics for a chopper (RC etc) should hold an edge much closer to 30 inclusive. Even if you then strop it so it looses another 3 degrees per side or so, it will still be fine enough across the apex to chop and carve very well, but be plenty tough. At a "clean" 30-32 degrees per side, I have had very good luck on everything from machetes to hatchets and they are far less likely to jump out of a cut.

Direct to your question - the finer you make the edge, the less resistance it will have going into a cut, the easier it will penetrate past the apex and the back bevel can do the hard work instead of the cutting edge, the longer the cutting edge will last. IMHO you should make the edge as fine as you can without being a PITA for maintenance, even if it compromises cutting characteristics for utility (draw) cutting - less "bitey/toothy".

 

[Fred.Rowe]

I'm not a fan of convex grinds but in the case of camp knives and choppers I relent. Convex edges open a cut instead of wedging into the cut. I like convex bevels on a chopper for the same reason. Most people who build competition cutters build them with convex grinds. Camp knives with hair splitting edges will not have them for long if used to feather or chop kindling. It too easy to get caught up in the race for the perfect hair spliter, when what is needed is a working edge sharpened for the purpose at hand.

 

[Sadden]

Well I NEVER EVER go steeper than 45* Inclusive , any more and its basically just a chunk of steel.

There is 2 separate parts to this question I see.

Durability - Resistance to chipping , rolling etc.
Abrasion Resistance - How long it will hold that edge for.

While a steeper angle is more durable , you do reach a point of diminishing returns for a given task. For example , using the numbers Heavy Handed used , if your knife is stable for your uses at 30* inclusive , then taking it up to 50* inclusive gains you no additional usable durability , while greatly diminishing your sharpness. I would also agree with HH in regards to getting up past the bevel and letting the main grind lines of the knife start to do the work (assuming we are talking about chopping)

As for abrasion resistance well that's more something that you need to look to your steel and heat treatment to provide. But for chopping typically finer is better.

On my personal beater/outdoor knives I normally go to around an 8k finish (shaptons) , and then strop. With my kanagaroo strops loaded with CBN I can actually intentionally use some pressure (say 5lbs or so) in order to microconvex the very edge of the edge. This does seem to give the edge more stability under harder use. And allows me to push the edge to a slightly steeper angle. I will be testing this out more next spring but so far results are good. I wouldn't recommend that with a cow/horse leather strop. Too much give will completely round off the edge.