I know you guys have probably beat this dead horse into the ground, but I spent about a half hour searching with no good results.

Let's talk edges. So I've recently have been struggling with getting a good edge on my latest creation.

My lastest and greatest is a camper/hacker/tactical blade made from s30v. The blade is .185 thick with a bevel that is 1". Thickness at the edge is .020. Oh yes...HT is by BOS so it's good.

I've been a fan of the microtooth. It always seemed like when I used the polished edge the balde would always state when I went to turn a 2 x 4 into toothpicks.

So I've probably sharpened this beast about 15 times already just trying to get a good performing edge. Like I said the knife will be used mainly for camping. So I'll need to have an edge that will slice wood(of any type) Chopping wood, cut rope, skin out any critters that I might take during hunting.

Now I know that the "ALL PERFECT All in ONE Knife" doesn't really exist. But So far I haven't been able to get a good edge that I'm happy with.

What are most of you guys using as a final edge for campers.....Polish-Microtooth. And more importantly how are you guys doing your sharpening.

Thanks guys,

Jimbo

P.S. I've tried the "extra" stropping for the s30v and I've actual had negative results.

I never used this steel but... You should try some different stones. If your blade is relatively soft, then harder stones makes better edge. Norton India oilstone makes a good, sharp and very agressive edge.
With harder blades a soft japanese waterstones may be a good.

I find that in the field, it is hard to go past diamond sharpeners. I have a number of the fine grade (Red) EzeLap small stick-type sharpeners that do quick work of the high tech steels. They are quick on knives with thicker bevels and are really the only way you can effectively sharpen the new CPM type steels without taking a day and a night.

The coarser grade diamond stones are even faster and gives that toothy edge which slashes well through meat but be careful if trying to push cut - it'll bite deep through skin !! Don't ask me how I know !!

Strap one of those (you chose what grade) to each sheath and you'll be assured of long happy use of your knife in the field. Coarse is about ?120grit, Medium is about 240grit, Fine is about 600grit and ultra fine is 1200grit.

Be aware that even though they are good NONE of the diamond coated hones last forever. Jason.

I think the problem with sharpening S30V is all that free chrome which is gummy stuff. I'm a strong believer in the polished edge, which if properly formed will certainly bite into pine without much trouble.

I use convex edges, shaped on a slack belt, though in the past year I've been using a rotary platen so I can better control the shape of the convex. For fine slicers I keep the convex shape flatter, and for choppers I allow it to be more rounded.

I think one of the problems some folks have with polished edges is that they polish them too much at the very edge, making the final angle there a whole lot steeper than you think it is. It will shave, but not hold up long and will tend to skate with glancing cuts.

When I shape an edge, I lay in the bevel angle I want with 120 grit (80 grit on BIG blades), and follow that by carefully raising a wire edge at the same angle with 220 grit. From that point until I am on my next to finest belt I try not to touch the edge again. I then use the 220 to break the corner on the initial bevel to begin shaping the convex. Fron there on I use each successive belt to sand towards the edge (without touching it but maybe only slightly) and up the blade to extend the convex. I go through Norax 45, 30 and 16. Sometimes with small knives I finish with a Norax 5. With the next to last last belt I use I spend a lot of time very carefully raising a wire. The important thing is to not let the belt lap over the edge, but just to sand it smooth. the final belt is for polishing the whole convex, again being careful to avoid allowing the belt to lap over the edge.

With that final wire formed, I touch the blade to a loose buff with white compound and clean off the wire, which at that point is pretty fragile and comes off fairly easily. If any tends to cling, I strop it off. It's important to avoid letting the buff run over the edge, so I keep the edge pointed well away from the buff.

The problem with a slack belt is that it wants to run up over the edge if you push into it too much. Since you tend to do that instinctively with finer belts, you often round the edge into a steeper angle without realizing it. Avoiding that takes some discipline. I suspect that's the source of your skating problem.

Thanks for the thoughts guys,

I usually start out using a fine silicon carbide stone. Once I have a nice fresh edge I move to a hard ark stone. I've found that jsut a few strokes on each side works the best. (I also use a marker to match the orginal angle) After that I goto the strop for a couple strokes on each side.

I've pretty much confirmed that the more I strop....the duller the balde. But that's probably something I'm doing.

So I'd say that I have a microtooth/polished edge.

Good thoughts on the edge geometry Jerry, I try to keep the same angle.....If fact I'm ultra anal about it. I learned a long time ago that the best edge is a nice straight edge.

I did finally get an edge that I'm happy with shave a 2 x 2 down to a toothpick and still shaves hair.

Jerry why do you perfer the polished edge?

Thanks again guys

It's about all those little microteeth you're talking about. If you think about the structure of that edge, what you have are a series of little pyramids sitting along the edge, and the only thing that's sharp is the top of the pyramids. The areas in between are necessarily dull, because they end before they get to the real edge. Unlike a polished edge, those little teeth are exposed to stresses from all directions, even slicing, so they are much more prone to breaking than a smooth polished edge. Once the tops of the pyramids are broken off you have an instantly dull blade. A smooth polished edge will take a lot more beating before you've micro-chipped or rolled it into dullness.

S30V simply should not go dull with stropping, unless of course it's knocking off the tips of those pyramids.

BTW, you can't even approach ANAL on edge angles compared to the people who are fanatical about woodworking tools. I've been corresponding with folks in that world lately, primarily on the use of CPM-3V for woodworking tools and it's been a revelation. They hold edge angles to the fraction of a degree and polish the edges to the sub/micron level - by that I mean they go down to submicron abrasives. We've looked at some of the more challenging applications there, like mortising chisels, plane blades, and lathe tools (chisels and gouges), etc. They've analysed the results by empirical testing as well as photomicrographs. Very enlightening stuff.

One thing we're concluding, which a lot of people in the knife world have argued for some time, is that edge angle should mean only the FINAL edge angle, and not necessarily at the front of a flat bevel of the same angle. The convex edge, which they in fact found on old woodworking tools used by the old masters and which they thought were simply artifacts of age and maybe subsequent abuse, were in fact the edges those old masters likely applied with their stones as a consequence of doing everything by hand. They just happened to result in convex edges, but they also "happened" to cut better than anything made in the modern era of "better" steels using modern sharpening equipment, applying very precise flat bevels.

Granted, woodshaping tools cut differently than knives, but the strength and integrity of the edges are similar problems. From what I've seen in photomicrographs of M2 tool steel edges compared with CPM-3V edges, I'd say their stresses are much higher than ours. M2 is a pretty tough steel, and I've seen it destroyed.

Cool Stuff Jerry.

Now if I would have to assign a cause to the dulling of s30v, I would say operator error. I noticed that I had a slightly larger angle then the stoned edge, SO I probably was rounding the edge.

But now back to the microtooth. I see your point about the pyramids, BUT if you stone a fresh new edge(down to the point were you get the wire edge) I would think the edge would be more like a serrated edge. Sharp all around but with high spots(pyramids)

Just thinking out loud is all. Like you said, those woodworkers are using their tools in a very abusive condition, If they are seeing better results with a polished edge, you have to take that into consideration.

A wire edge doesn't mean a uniform edge. You can get a wire edge with a 60 grit belt, and that's a pretty ragged edge. As you go down from there in grit size you are sharpening less and less of the hollows between those pyramids. At the finest grits, you're not even touching them, so they are definitely not sharp. What you're creating is more like a saw blade than a serrated edge, close but not the same. That's my take anyway.

oh don't get me wrong about uniform edge. I just learned this long ago that if you have a worn down edge, the best way to know that you have a nice fresh edge is once the wire edge starts to form.

Now dealing with the wire edge is a whole different ball game.

Anyway Jerry how far down do you go with the polish.

I've seen some edges that are mirror finished. I guess that's my vision of a polished edge. Every time I've use one like that I get that skating effect I was talking about.

I always go to 1200 grit, sometimes 2000.

The only way the edge can skate is if the final edge angle is greater than the attack angle of the cut. Otherwise the edge should bite into the material. That is especially true with convex edges, since they are relieved, i.e. angled back, more than a fixed bevel. As I said, one of the common consequences of polishing edges is to make the final angle greater than you think it is.

There is also another consideration, though knifemakers are not supposed to mention this. Sometimes, albeit rarely, the user is cutting at the wrong angle... :)

If you want to make toothpicks you may need a toothpick-making knife. Most choppers are designed for fairly high attack angles, and to use them for shaving off thin slices is just not what most are designed to do. You can make one do that, but you'll have to drop the edge angle to below where it will be as strong as you might like it to be for heavy chopping.

Jerry,

You must have a better touch than I since I can't buff an edge with a loose cotton buff without losing the edge. I always use the hardest cotton wheel that I can get.

Gary

Gary, I'm sure that just means there's something different in our setups or something we're each doing that's different. As you know you do a lot of things you take for granted, so you don't even see yourself doing them.

I'm using a 1750rpm, 8" loose buff that's old and worn with a bit of somebody's white compound and I haven't a clue whose or what it is. I've had/used that same buff and bar of compound for years.

I do sometimes find the edge going away when I buff, but I've generally concluded that only happens to me when I get the edge a tad too steep.

Experiences may vary...

I have tried dozens of different buffing compounds and found the green from K&G to be the best by far. I can't think of the name of it but it was the more expensive green compound. I use this on a sewn buff using very light pressure. For some reason this compound does better than anything else I have tried. But only when I get the angle correct. I have been going down to 400 or 600 grit and getting a really scarry edge but I think I will try going finer and seeing if the edge will last longer. Thanks for all the info.

I just attempted the sharpening on a buffer method that Jerry Hossum described above. MAN !! - it works !!!

I had an O-1 blade, convexed edge with a rough 180grit edge (dull belt) and wanted to polish the lower 1/4inch to make it slick for chopping tests. I polished it edge down with the green chrome oxide on a stitched buff for just a few seconds.

I thought I wasn't hitting the edge - but when I checked the sharpness after - WHOA !!! It knocked off hairs like you couldn't believe. Those hairs were running for their lives.

Jason.

Jason, just so there's no confusion, that's not MY method. It's the method I use but so too do many other knifemakers and have for a long time.

Your using green chrome makes what you're doing somewhat different than what I do. Green chrome cuts steel pretty efficiently and when used on a sewn buff it is even more aggressive, so you're probably doing some actual sharpening on the buff. What I do there is to simply brush off the wire edge and strop it a little. Those are probably milder versions of what you're describing.

Glad it worked though.

I love this thread!!

I just hadn't thought of trying that method till I read your post on this thread. I know its an "old" technique.

When was doing it I was actually NOT trying to do the edge, just the convexed area above the edge. But obviously the loose fibres on the buff did get to the very edge. The angle is still very good, so it wasn't buffed away and yes, it did a good job of removing the wire. Of course, it will work best on convex edges, or will turn a crisp cut edge bevel into a washed-out convex edge ... Jason.

Regarding the green buffing compound, I would rely on Jerry's advice. He has a hundred times the amount of experience I have. I think the reason the green worked for me was I did not go to as fine a grit as Jerry and needed something with a little cutting action to do the buffing. I haven't tried it yet but I am sure Jerry's method is superior.

I alway thought green was a finer grit than white. I have not had a lot of success with white. Keep in mind though I am not a professional knife maker. I have been making them for 25 years but I am still an amateur.

Jerry,

Do you have any online or print references from the woodworking people?

Gabe, if it's online I don't know about it. All of my communications have been by email, and I have some sense that's intentional maybe. I got in the loop because of my work with 3V; Crucible sometimes send folks to me to talk about it. From there we just continued to talk edges and the notion of the convex edge triggered some thinking about what has worked, without there having been a prior understanding of why.

I should qualify my earlier use of the term "we". My role has been strictly limited to that of an outside source of anecdotal and sometimes useful information.

It's my understanding that as a result of this work, 3V will appear in some high end woodworking tools in the not too distant future, and the concept of convex edges is now being investigated under controlled conditions. If you have an interest in it, I'll try to keep you informed of what I know.

I'd appreciate it.

Do you know if anyone has ever connected with the people at Specialty Blades, Inc.?

About SBI - on the Specialty Blades website (http://www.specialtyblades.com/about_sbi/history.html)

Gabe, I don't know. From what I read there they could use some thoughts on steels. Or maybe they just need to update their website. The only CPM mentioned is CPM440V (S60V) which is certainly the weakest of all the CPM's.

I wouldn't mind their making some S30V razor blades though! :)

Jerry, you talk about using a loose cotton wheel, with white buff compound. I was wondering how that compares to using the felt wheels I have been so fond of. I know they are aggresive but is that only because of the green compound I use? If I was to use white would I be able to control the way it works that you talk about?

Jerry I am interested in Vishnu's question too. I use compressed paper wheels for sharpening.
Thank you very much Mr. Hossom I have learned tons of valuable things from your post. You DA Man.

redhawk - I stated out with paper wheels and loved 'em. However, I found the edges didn't last at all. I'm currently of the opinion that with the hard wheels you create a 'hollow' grind on the edge. Actually the opposite of the convex edge Jerry is talking about.

Currently I'm sharpening with a mousepad platen (kinda like the rotary platen in effect). I'm raising a burr with each belt from 220 to 5x. Then I use a leather belt to remove the last of the burr. I have to say they come out crazy sharp. However, I don't think I'm getting the same exact edge shape as Jerry. That's something I'm gonna have to try out.

FWIW, For almost all my sharpening, I set the platen at 15 degrees off level, with my mouse pad on top, run the belt backwards, and hold the knife level. This gives me a 15 degree edge plus whatever convex effect I get from the soft platen. The leather belt runs at the same angle, but curls a bit mofe over the edge because of it's softness. Would be nice to see it under a 3D microscope or something.

Steve

Thanks SteveS. I have always loved knives and the past few monhs I have decided to make my own. I am buying blades and putting handles and guards on them while I study the post of the masters such as yourself and Jerry H. Your knives are awesome. I hope to be able to do something like that someday.

Redhawk,

You do me WAY too much honor to mention my blades and Jerry's in the same paragraph. I'm just a hobby kinda guy. Serious in my application, but not the experience and knowledge of a real Pro, like Jerry.

After 2 and a half years, I'm just getting to the point where I know I don't know squat.

Thanks for the complement, tho!

Steve

PS, buy your blade blanks from a maker after your first few commerical blades. Loads of difference and a more usable product.

Your knives look great to me Steve. I don't really know who is who in knifemaking yet.
Where can I buy blade blanks?

Redhawk, This would be a good point to open a new topic in the newbies area. Don't want to hyjack this thread, you know.

Steve

Ooops sorry forgot myself. I will post there.

Here's a listing of Suppliers done my Craig Wilkins. It has pretty much anything you'll ever need in knifemaking.

http://www.internetbusinesslinks.net/SupplierList.html

As for my use of the loose buff, all I am doing at that point is removing the very fine wire edge that's left after I'm done on a 1200 or 2000 grit belt. The edge is already shiney and I just want to get rid of that fine wire. I'm not doing any sharpening with the buff. The harder the buff, the more aggressive it cuts, regardless of whatever compound is on it. I can tell you, a felt wheel with green compound can cut very aggressively. I used to use that for mirror polishing and would sometimes have trouble with pitting caused by overpolishing. I have a paper wheel and have used that a few times just for stropping. I let the white compound wear off long ago and just use the paper as a strop on blades that I just want to touch up. Great for kitchen knives.

Steve, I'd guess that setup you're using would work great. I use a somewhat similar arrangement, with the rotary platen I got from KMG and set the tension to whatever shape I want the convex to be. I usually keep it vertical since I'm more often sharpening a number of knives at once and they don't all take/get the same edge profile, and I can judge the angle better with the platen at 90 degrees.

Have you thought about covering your mousepad with some graphite belting to make it wear a little better?

Jerry,

RE: the platen

Yes I do use graphite belting. Here's a pic of the setup:

http://knives.mylamb.com/stuff/rotary.jpg

The sheet metal on the back let's me slip the thing on and off the regular platen. I use it for convex edge grinds, handle work, ... I'd say it's on there more than it's off!


I found a pic of how I setup my platen. If I could judge angles with the platen upright I would. But you know how it is. Once you have something dialed in, it's hard to change.


http://knives.mylamb.com/images/platen.jpg

Steve

It's not "hard to change", it's IMPOSSIBLE to change!! :)

That's a great looking setup and a WHOLE LOT CHEAPER than a rotary platen. Wish I'd thought of it before I got the platen.

What's not been mentioned is that the "hottest" hand-sharpening method for woodworking tools is the "scary-sharp" method. The woodworker uses various grits of sandpaper that have been spray-glued or taped to a piece of glass to keep them very flat. Usually oil is added to the sandpaper surface. You can sharpen nearly anything to razor sharp in a short time, if you just have a good variety of grits! Its also a good idea to have a jig to maintain a consistent angle.

TJ,

If want a consistent angle you don't need a jig. Try this:

http://knives.mylamb.com/calc.htm

Steve

Hey I make knives at 25 degrees and more that will shave all day. But then, I hadn't read that link before... :)

Actually, I had read the link and thought it was pretty clever.

The woodworking guys sort of do need a jig for things like planer blades. Otherwise you might sand in some twist that would mar the surface. That's a whole 'nother' world!

I have been using Jerry's suggestion regarding very fine belts to sharppen. I used a 9 micron belt that is well worn with a light touch. These edges have been lasting much longer then my previous edges. Very light buffing at the end.

Thanks, Steve! That should be one of the forum's tutorials!!

Jerry pointed out what I neglected to include in my posting - When a woodworker is sharpening a chisel or plane, they often use a jig to maintain the angle AND to insure that the edge stays straight.

TexasJack,

I didn't mean to knock jigs. When I've used that 'calculator' with waterstones I found I could keep things real consistent, but it's a lot of work.

Kinda a montra-centering prep thing, then a confortable position, then locking your elbows, then moving your body, .... Even then one slip and ....

Jigs are good things.

I do like the coin trick for plan old sharpening on a stone. It is amazing how consistent you can be.

Steve