How do you guys approach thick edges?

[Jamesh Bond]

Just doing some pondering. My thin blades are hair splitting sharp, but knives like my Emersons, Cold Steel SRK, and others with thick grinds annoy me to sharpen. Diminishing returns for my time always end up with a usable, but unimpressive edge.

Obviously, my natural freehand inconsistency is magnified on larger bevels vs not being very significant on a really thin edge.

I can do fine with both hands on a large bench stone. But im always hearing success stories with people taking care of their thick, long blades with small ceramic rods, etc. I can do this, but not well.

i guess im picturing a guy in the field for extended time, with a Bark River Bravo or Cold Steel SRK, and a Gatco ceramic Tri Seps to touch it up with. Or maybe a recurved Becker, and a small diamond rod. I hear this kind of thing all the time. Does this happen?

How do you guys handle thicker blades without digging out the mouse pad and sandpaper or benchstone.

Are you using microbevels? How do you hold the tools when the blade is long but the sharpener is handheld? What about your convex edges.

I know this post is a mess but ive been puzzling over perfecting my technique forever. Having trouble conveying my questions.

In summary:

Primary concern is difficulty maintaining my thick, wide bevels. Getting them as sharp as they were new.

Secondary is how people are getting these great edges on long blades in the field.

 

[Jason B.]

Thick blades don't sharpen well, period. Not even in my hands does it end up all that great. Coarser edges help where the geometry has failed but eventually the geometry wins.

One mans great edge is another's dull as a butter knife. A ceramic rod only does so well, but to those using a edge that has hardly seen a stone in the past decade it must seem like the magical ceramic rod of sharpness.

Thick blades beneifit from convex grinds or thinning them out on a belt sander. Those are the only tricks I got.

 

[fervens]

Every time you go to sharpen, just take some of the shoulder off. Don't worry about thinning it all out at once. Fatigue will increase the chance of a screwie bevel. Eventually, the main cutting edge will turn into a micro bevel.

 

[Novaculite]

A microbevel is my solution, although that won't help much when it comes to slicing something. I have numerous old knives with thick blades, mostly hunting knives. The bevel, when sharpened at around 15-17° per side, can be between 1/8 and 1/4 inch wide, so you can imagine how fat these blades are. Cutting with a tool like that is seldom fun, the main reason being that the geometry of a blade that thick resembles that of an axe. When slicing something, what happens is that right behind the sharp edge comes a wedge that also has to be forced through the material being sliced. If you don't believe me, please sharpen an axe and use it to slice an onion or a turnip. Thus most of these old knives spend their time in drawers or are used as letter openers. They unfortunately are of historical interest only.

Microbevels on thick blades at least have the advantage of not having to grind steel off the entire width (1/8 inch and more) of the primary bevel mentioned above in order to maintain a decent level of sharpness. One good sharpening of that primary bevel should suffice for a year or more of just touching up the microbevel at around 25° on each side, depending on its use. My favorite kitchen knife is from China, one of those big square ones used for everything over there and about as thick as your average 8 inch cook's knife from Solingen. I sharpen the primary bevel about once a year at about 15° each side, and use a sharpening steel at maybe 25° each side to create and maintain a microbevel. A dream of a knife and a joy to work with.

Sam

 

[HeavyHanded]

I'm with Jason on this one - thin it out or convert to a convex. Fervens' suggestion to convert it over time is a good one if doing it by hand - otherwise it can be drudgery. Is well worth the effort though. The Bark River is already a convex, so just make sure you always pull some steel off the entire convex face as it wears or the edge angle will gradually increase to a poor performer. You can maintain for short stretches by just sharpening the edge, but this is no solution for long term. A small (4"x1.75") silicon carbide combination stone or a combination axe puck is much more versatile than a rod sharpener for convex and broad bevels.

When using smaller handheld stones or rods, I grip the stone with my dominant hand, tool to be sharpened in the non dominant, and find something to rest the spine on so I have two points of contact to steady the tool. If its a larger tool like a hatchet or machete I'll brace it on my knee for a second contact point. If there's nothing else stable or convenient, I'll draw my knee up closer to my face and use it for smaller tools as well.

http://i748.photobucket.com/albums/xx126/Millermeter_2010/07_zps24df8086.jpg

 

[Novaculite]

knives like my Emersons, Cold Steel SRK, and others with thick grinds annoy me to sharpen. Diminishing returns for my time always end up with a usable, but unimpressive edge.

Forgot to ask: What do you use these knives for? Chopping sugar cane or skinning deer or preparing dinner? Or something else?

 

[Obsessed with Edges]

On very thick blades that I've become sufficiently frustrated with to make the effort, I've often used a DMT Aligner clamp with my DMT Duo-Sharp C/F diamond bench hone to reduce the edge angle significantly (30°-25° inclusive at least). THEN, my preference is to begin convexing that thinner profile, focusing on leaving the crisp edge intact from the re-profiling, and smoothing/thinning and rounding out the 'shoulders' of that V-bevelled edge. Depending on the steel, I may use wet/dry sandpaper on stone/glass for that, or I may do the additional convexing on the diamond hone, if the steel warrants it (S30V, D2, etc). After first re-bevelling on the DMT hone, and assuming the resulting edge is fully apexed and sharp (I don't stop until it is), the subsequent convexing can be done at my leisure, over some time.


David

 

[2beagles121]

I've always used thick edged blades for a heavy use blade.A belt sander is about as easy a way to learn for a convex edge.After that a diamond steel will bring the edge back for a long time.For a blade that is most likely to see a lot of abuse i leave a course edge on it.

 

[REK Knives]

The way I handle them is either:

1. Regrind them so they are MUCH easier to sharpen and maintain
2. Back-bevel them and then micro bevel the edge (this option is mainly for survival knives or choppers). this option will retain a ton of strength still but yet make sharpening much easier and increase the cutting efficiency somewhat.

Take this knife below for an example... extremely thick edge, up to .070" thick towards the tip. After I reground it is around .005"

 

[BluntCut MetalWorks]

Josh, your grind is nifty awesome ... your wet 2x72 grinder didn't even break a sweat My poor overworked 2x42's platen has grooves in the middle - hey just another minor challenge on a lightning fast belt fpm.

edit: removed my useless comment...

 

[David Martin]

Every time you go to sharpen, just take some of the shoulder off. Don't worry about thinning it all out at once. Fatigue will increase the chance of a screwie bevel. Eventually, the main cutting edge will turn into a micro bevel.

I agree with this approach. DM

 

[Jamesh Bond]

Appreciate the input guys. Guess i just needed a reality check. Good to know im not missing something.

Thx.