Negatives of a razor sharp blade?

[knarfeng]

As Mike said in his thread, these edges are extremely fragile. I liken it to being related to a master craftsperson with a volatile temper: tread on eggshells and your efforts will be rewarded beyond your expectations; get even a little careless and expect a devestating blowout. I don't go 4 per side or up to 400,000 mesh (14,000 to 90,000 is fine enough for me) and do add a microbevel.

Now if you look at angles (and we all do), you'll see the grooves scored into your knife with a given grit are deeper at the edge when the angle is smaller. The grooves add friction and if the edge isn't perfectly aligned (as in any edge after the first several uses), that friction aids in starting the cut. I don't have the ratios all worked out, but a 600 grit edge at 40 included degrees and an 8,000 grit edge at 8 included degrees both feel equally 'toothy.' On the flip side, I've thinned out edges at low angles with coarse benchstones and coarser sanding belts and the blade felt like steel wool. So you might well be experiencing a relative identical level of polish in your work knife as a sharpening geek has in a kitchen knife.

YES SIR. I agree there is a difference between angle and smoothness of the blade surface.

I find myself cutting heavy plastic a lot (homeowner fixit projects). For that I like a somewhat more oblique edge angle, but a very smooth surface finish on the cutting edge.

I do edge comparison testing at 15° per side. My EDC edges are sometimes 15° and sometimes 20° per side. (I'm still not sure what angle I really like best for everyday chores.) If I'm sharpening with the Sharpmaker, I'll stop at the fine rods. If I am using DMT stones, I stop at the extra fine.

 

[gunmike1]

Mike, I bow to you and Thom as the maestros of sharpening, but how well does that 4° edge do on cutting garden hose or trimming up plastic toilet tank parts? That's the sort of jobs my knives perform.

(I can't do anything with the kitchen knives because my wife uses/abuses them. One must pick one's battles and she refuses to treat "her" kitchen knives with care. So I don't try for fancy kitchen knives or fancy edges in the kitchen. But, she is an awesome lady who has been married to me for a bit over 25 years, so I ain't complainin'. Much.)

Knarfang, as I said in my post and Thom pointed out even a slightly imperfect cut or a bad hit on the cutting board can blow out my edge on the Takeda. I actually have given in to 10 per side microbevels on that knife just due to the shear time it takes to full bevel sharpen a 10" knife. Also, as Thom pointed out, cutting hose or plastic toilet parts and cutting tomatoes are wildly different tasks calling for very different tools. You don't take a Big Rig to the drag races, do you?

On pocket knives I usually run a 15 per side or so microbevel on any knife that will see any cutting of things like hoses or heavier plastics. If I may be cutting metal or if it is a steel that has proven chip happy in the past I may even go a bit fatter, but straight cutting prevents a lot of chips. Tougher materials of course make it hard to cut dead straight, hence the need for thicker angles on heavier cuts than guillotining a tomato. On my precision cutters like my ZDP 189 Caly Jr. with a Krein Grind I go with a much more acute angle because the toughest it will see is a blister pack or cardboard and ZDP 189 as Spyderco does it has held up very well for me without getting chippy at really thin angles.

As for grit, just like Thom said the more acute you go the "rougher" the edge will seem at the same grit. My Takeda at 4 per side actually seems quite toothy at 2000 grit, and it does about equal out to a 400 grit edge at 20 per side. As a man into OCD and overkill I often go to .05 micron finishes on everything, but for the most part if I just want a long lasting, hair whittling edge quickly I will do a 1000 grit microbevel and make sure it is burr free. Sometimes, as the "guy who gets knives really sharp", I do feel the need to carry a .05 micron edge no matter what, so I always have my lovely little precision cutter or some other knife to show off with on top of a work horse.

Mike

 

[sodak]

And heavens help any guy who tries telling his significant other how to handle kitchen cutlery.

Very true. The kitchen is the one place that I've been able to successfully avoid buying knives for. I'm afraid of how much money I would spend. And my wife thinks nothing of dropping the knives into the sink and piling all the dishes on top for soaking. For a while.

It would drive me crazy, and isn't worth it. Unless I can install a locking drawer in my kitchen. Hmmm....

I've blown out my share of thin edges also, but I really do think that most people can go much thinner then they often believe. Plus, it's fun!

 

[knarfeng]

Thanks, Mike and Thom. I always appreciate reading what you write.

 

[thombrogan]

It's really tough to get Mike or me to sharpen or talk about sharpening.

But it was fun talking about it with you and seeing sodak, one of our evil mentors, chime in.

 

[gunmike1]

It's really tough to get Mike or me to sharpen or talk about sharpening.

But it was fun talking about it with you and seeing sodak, one of our evil mentors, chime in.

Knarfang, you brought out an old school trio of darksiders to BS about sharpening and trying to forget about the wrongs our women have perpetrated on our cutlery! I do enjoy talking about sharpening and hearing how others sharpen so I can try to learn from other's experiences. Of course I try to pollute people's minds with my "thin is in" BS, but most can filter through that. Fun, thought provoking discourse is what makes the forums fun, as long as we aren't threatening to strangle those we disagree with in the discouse!

Mike