Proper way to sharpen knives

Jimmyjanx1 said:
I have been looking at the work sharp guided field sharpener for out in the field. But I sharpener all my knives at a 25 degree angle and the diamond plate guides are 20 degree and the ceramic rod is 25 degree. Would I have to free hand the diamond plate?
Click to expand...

Yes, although my question to you is, why do you sharpen everything at 25 deg.? Pretty high for most uses... you might be surprised how well a 20 deg. (or lower) edge holds up... and how much better it cuts.
 
Consider this...

[video=youtube;Nt4Fh7_KFG4]http://www.youtube.com/watch?v=Nt4Fh7_KFG4[/video]
 
Jimmyjanx1 said:
So if I go down to 20 my knife will cut better but be more prone to damage
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Maybe, maybe not. Depends on what you're cutting with it. Also consider that even perfect edges at 20°+ per side are never going to cut as well as those at 15° per side (30° inclusive) or lower. At some point, it won't make much of a difference in trying to protect an edge from damage which is (geometrically) a poor cutter anyway. There's a trade-off between getting the best performance for YOUR uses out of an edge, before it needs resharpening, and creating an edge that's just durable (i.e., wide angle), but will never cut very efficiently in the uses you give it.

It generally takes some time using the knife for the tasks you typically choose for it, before you'll know if it could be improved, one way or the other. As the above-linked video said, if you notice the edge is holding up well for the tasks you give it, try lowering the edge angle the next time around, and see if it still holds up well enough for the greater cutting efficiency attained at the lower angle. The vast majority of modern knife steels from reputable makers will easily hold up to normal cutting tasks (non-abusive, i.e. not used as a sharpened prybar) at 30° inclusive (15° per side) or lower, and a thicker edge on such a blade is often a waste of it's cutting potential.


David
 
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I sawed off a piece of wood under exactly 15 degrees. Screwed a piece of wood on the bottom to keep my ultra cheap, in oil soaked sharpening stone in place.

Just keep your knife vertical and try to slice a piece from the stone.

Made a strop from a piece of leather glued to a piece of flat wood and charged with polishing paste.

This, poor man-do it yourself sharpening system makes knives really razor sharp, and costs very little.

Stone € 3,95
Wood € Free ( only need a good saw )
Leather € 5,- maybe?

Edge € priceless.

Result after stropping is a razor sharp edge, don't be fooled by the looks, this works! And if you want a system under a bigger angle, just saw of another piece under another angle.
28925eb5201a373fc4f5a5b18abba8cc.jpg
 
iMarcoU said:
I sawed off a piece of wood under exactly 15 degrees. Screwed a piece of wood on the bottom to keep my ultra cheap, in oil soaked sharpening stone in place.

Just keep your knife vertical and try to slice a piece from the stone.

Made a strop from a piece of leather glued to a piece of flat wood and charged with polishing paste.

This, poor man-do it yourself sharpening system makes knives really razor sharp, and costs very little.

Stone € 3,95
Wood € Free ( only need a good saw )
Leather € 5,- maybe?

Edge € priceless.

Result after stropping is a razor sharp edge, don't be fooled by the looks, this works! And if you want a system under a bigger angle, just saw of another piece under another angle.
28925eb5201a373fc4f5a5b18abba8cc.jpg
Click to expand...


The is exactly how the SharpMaker and other "turnbox" style systems are designed. Sometimes it's difficult to keep eye-hand coordination perfect when looking at a very small angle, and at odd distances or angles from the body. But it appears much easier to keep the blade at a perfectly vertical position while working the stroke. There are many ways to sharpen, but the fun is finding one that works best for you. Oh, and the zt350 should have no problem getting the re-curve, as long as you work it slow and easy....usually near a corner of the chosen stone.

I like the clamped systems, but if you only have a few nice knives, no reason why you can't start out cheap and learn the basics of sharpening and blade geometry.
 
Several years ago, I built an adjustable "sharpening ramp" after watching some videos from BF member "Unit". See it in action here:

[video=youtube;Um6MvhCucaQ]https://www.youtube.com/watch?v=Um6MvhCucaQ[/video]

...and here's his video on how to build version 2 of his wedge/ramp:

[video=youtube;qeWmD5ATBKE]https://www.youtube.com/watch?v=qeWmD5ATBKE[/video]

Mine is different, but uses the same principles. We built mine at work using our CNC router. Anyway...

I found it very instructive to use this device for a few blades. In fact, it provided a real "ah ha!" moment for me with one knife that GREATLY helped my sharpening. This led me to secrets #6 and #7 of sharpening. So it was a really valuable experience.

That said, I haven't used it in several years, as I found the mechanics to be... awkward. I found it hard to maintain a true "level" when using it through the length and curve of the blade. For some people, it might be an end game tool. For others, it might speed them along the path. I just thought I'd mention it.

Brian.
 
Jimmyjanx1 said:
So if I go down to 20 my knife will cut better but be more prone to damage
Click to expand...

Hi

Yes, it depends :D basically what the other guys said

Consider that under 15 dps edge can chop bones
And 12 dps edge can still shaves/whittles beard hair after 1000 slices of hardwood

So if you're chopping rocks and bricks, 25dps might resist damage better than 20dps,
but if you're slicing stuff, 25dps dulls faster than 20dps even if those are microbevel angles

So, recommendations for 25-30 degrees per side sharpening angle
are great for first time sharpeners or if you only have seconds and need results quick,
much better than a dull knife
... but try and do a couple hundred slices with that edge angle ... ouch :)
 
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