sharpening question

H

happyhunter

Joined
Aug 16, 2005
Messages
71
I have been trying to get a good edge on my Howling Rat ever since I got it. I guess I am sharpening challenged....

I have used my mouse pad and 400 grit wet/dry sandpaper. That helped matters a good bit, but it was not where I wanted it to be. So I got some 1000 grit. That made the edge all nice and shiny but really didn't do much to improve sharpness.

Right now it is barely acceptable. If you hold up a piece of paper (pinch it between four fingers so the paper is supported on each side of the blade) then the knife can just barely slice through it. It barely bits into a finger nail.:(

I can put a pretty decent edge on my BM AFCK with my Lansky. I use the 25 deg setting with the coarse and med stones and the 30 deg for the fine. That will usually shave the hair off my arm. I am about to do this to the rat. I am rather frustrated at this time.:confused:

How do you guys get this sharp?? Do I need 2000 grit? What is a strop and how do I use and make one??
 
Happyhunter - here's a link http://www.swampshack.com/ for you to check out. Click on "Keeping it Sharp" near the top and you will find a lot of good info. I am by no means an expert on convex sharpening, but I gather it takes some patience in the learning stages. Most people claim that after they "get it", it's easy and quick. If you read all this info & still have questions, post back here - you'll get help. :D

Good Luck,
Greg
 
Greg,
thanks for the relpy. I have read several of those threads before and I just reread them again. I still don't get this. What grit sandpaper do I need to put a hair shaving edge on this thing? One thread said the alignment is the only thing that is critical (that grit did not matter). If that is true then this thing was not aligned at the factory.

I have a weight lifting belt I am going to try to strop this on. I need to read up on strops some more. But my biggest questions on strops are: What side do you use? The smooth side or the rough side? How do you load a strop? Just rub it on in a thin layer?? I know how to load my 1911 but never tried to load a belt before.
 
I'm really ignorant about sharpening and knife edges but I have a semi-related question about sharpening. . .I went to a knife shop of a friend of mine and showed him my new HR. He's been around for over 20 years and not a greenhorn on knives.

His recommendation to me about sharpening my HR is contrary to what I read and have learned here and so this creates some cognative dissonance since I am trusting both sources vis 'a vis my knife store buddy and the sources here.

I went to his shop because I know him and he provides knives and sharpening supplies to the region. I wanted to purchase a strop and leather compound from him. He teaches people how to sharpening including stroping. He looked at my knife and asked me why do I want to strop it when that is typically reserved for really fine edges like filet knives, razors and other really fine edges and the convex edge is more like an ax edge and is designed for more rugged taskings. So, he asked me - and I don't know the answer thus I'm posting it here - why would I want to strop this edge. I said "because that is what everone is telling me!"

So, can anyone answer this question - why should I buy $60 worth of stroping supplies instead of using a standard stone or steel?

I'm not being argumentative here - purely trying to learn!

Q
 
Quirt said:
So, can anyone answer this question - why should I buy $60 worth of stroping supplies instead of using a standard stone or steel?

I'm not being argumentative here - purely trying to learn!

Q
Click to expand...

Hey Quirt.

I'm a bit of a butcher when it comes to sharpening my knives. Wait, maybe that's not the right analogy -- butchers know how to sharpen knives. ;)

The convex edge adds strength. But I am so used to a v-grind that I always reprofile my edge. I don't lose that much strength in the edge, but I suppose I do lose some.

I use a diamond stone that I have mounted to a piece of 2x4, which holds it at the right angle. I use a circular motion to get the edge sharp. The big deal to me is getting that little "wire" that forms to come off. This requires a bit of patience IMO.

Good luck finding your answers. I have my method, but I know that there are a lot of knife connoisseurs out there that would shriek if they watched me sharpen my blades.

:D -360
 
Greg,
thanks for trying to help. I have had log on problems with the site today too. I have learned to copy my text before submitting a new post (that way you have it if something goes wrong).

I was really frustrated with my HR today. Part of me wants to send it back and let the factory sharpen it. This knife does get my award of "dullest out of the box knife I have ever bought". But I need to know how to sharpen it for when I make it dull:)

So how do I learn to do this?? I have already made it sharper than the factory did, so I am doing something right!!

I tried the magin marker trick. When I use a mouse pad and 1000 grit, I am wearing off magic marker from the whole grind area. So it looks like my angle and pressure are OK.

So far I have used 400 then 1000 grit paper. Should I have used and in-between grit?? How much sharpening do you do for each grit??

Well, I think I just figured out the problem, I think. I put magic marker on the grind area and clamped the knife in my Lansky. Used the fine stone to see what angle the edge was at. The 30 degree setting (which is the widest, bluntest, most heavy duty angle on a Lansky) removes marker from the middle of the grind area. Meaning the edge portion is even steeper, or blunter. Is this the normal shape of a convex grind or is mine ground wrong?? I guess it may seem weird to talk angle on a convex shape, but the convex shape would change angle as it nears the edge. You could machine and hone this perfectly and a wide angle will not bite like a narrow angle would.
 
360,
it is nice to hear that some people remove the convex edge. I am thinking of doing that. I do like the idea of sharpening with a mouse pad and sandpaper. That would be light to carry.

How hard is it to reshape? Does it eat-up very much "stone life"? How long does it take... like is it much more time consuming than a normal knife?
 
360 - thanks. We tried a similar method of running the HR through a pair of steels with the angles set at 22.5 degrees to see if the steel would touch the edge or the side of the edge. Using a magnification lens we looked before, during and after the steel sharpening and could not see any modification to anything other than the actual cutting surface itself. Note: We had three observers - myself, the knife store owner and a guy who sharpens knifes professionally. Now, if this edge is truly convex one would surmise we would have altered or affected the sides of the edge instead of the very edge itself - but apparently we didn't affect it at all as the steel just took the edge sharper.
 
The Lansky came out last night and put a 30 deg edge on the rat. Now it shaves quite nicely!!!! I used the 30 deg setting for the coarse and med stones. Then I raised the guide rod on the fine stone so it was just a bit steeper, putting a nice edge just on the very edge. Nice and sharp now.
 
Here's my disorganized $0.02 worth on your sharpening quandry.

First off, here is a link to a page that outlines graphically and concisely the differences between the flat and convex grinds when applied to primary bevels and edge bevels:
http://home.nycap.rr.com/sosak/convex.htm

You would use your 400 grit paper or other coarse abrasive to *establish the angle* on your cutting tool. This is where you are hogging off a bunch of metal in a rough fashion, producing a ragged toothy edge on your blade. You then use the 1,000 grit paper or other fine abrasive for *polishing* your cutting edge. This is where you reduce the size of the ragged teeth on the edge to a size small enough to be considered insignificant in your usage of the edge.

360joules is right on the mark in calling for the formation of a burr "wire edge" that forms when you are sharpening your knife. If you aren't getting the burr forming as you sharpen on your coarser stones, you haven't worked your edge thin enough yet (i.e. to the point where it is the intersection of two planes). If you have trouble getting the burr to form, color the edge grind with a magic marker to insure that you're removing metal from the entire edge bevel. After coloring your edge, adjust your angle as needed and keep sharpening at it until the burr forms. The burr will be ground off on the fine grit stones or can be removed on a ceramic device like the Spyderco Sharpmaker.

For example, a 600 grit waterstone edge might be considered "good enough" on my pocket knife for everyday chores. However, a 8,000 grit waterstone edge is what is called for on my woodworking paring chisels, with a 12,000 or higher edge being preferable.

As you step up through the grits while sharpening your edge, remember that you are looking to remove all of the scratch marks left by the previous grit before proceeding. This is especially true right at the cutting edge. A magic marker becomes your best witness. It tells you the truth about where you are (and are not) abrading away metal with your stones.

Here is a "how to" sharpening page that also talks about various angles used to approximate a convex edge with a series of increasing flat angles:
http://gpvec.unl.edu/filesdatabase/files/feedlot/sharp1.htm

There is a new forum here on Bladeforums called "The Toolshed" linked below. That forum deals with sharpening, modifying, and maintaining knives. Sharpening and its associated equipment is an ongoing discussion there.
http://www.bladeforums.com/forums/forumdisplay.php?f=794
 
Find the edge and strop. Good advice marking the edge - colored compound in strop will do that too. Maybe practice on another knife.

The convex edge on my BR came very sharp. A few strops and it was hair-popping. I'll do my best to maintain it, though. I consider the factory edge on the Spyderco CJ ZDP-189 sharp (for its blade size).
 
If you cannot cut paper with the edge you do not need a finer abrasive, you need to do more work (correctly) with the abrasive that you started with or you need a coarser abrasive. If you can't cut paper you either have not removed material all the way up to the edge (you haven't really started working on the apex of the edge) or you have been doing something else wrong and you are making your edge duller or more obtuse. 400 grit is a reasonably fine grit and will certainly produce a paper cutting edge, 220 grit is fine enough for that if used carefully.

I would guess that one of two things happened: First you just didn't sharpen long enough using the 400 grit for the amount of material that you needed to remove or Second you got impatient and started pressing too hard against that mouse pad and your 400 grit paper started to wrap around your edge and started to dull it. The solution is to go to 220 grit paper and use light pressure until you start to be able to cut paper. Then switch to the 400 grit. Then go 600 grit, 1000, grit and 1500 grit. Everything above 400 grit is optional. At each step you should be able to cut paper. Don't push harder, go lighter and use a lower-numbered grit when you want to remove more material using a mouse pad. Be patient and gentle. Finish each step before you move on.

If you need to go faster use a hard medium-coarse bench hone and some higher pressure. A bench hone won't wrap around your edge if you apply high pressure. Subsequently go to 220 grit paper etc to get that convex finish.
 
I used the lansky to put a thinner edge on my HR. It worked so well I did the BC also! One thing I noticed, using markers, was that the angle settings on the lansky did not result in the same angle settings on the blade, I'm not sure what that means exactly. I used the marker and went by sight.

I didn't take the whole edge down to one angle, in other words, there are a couple secondary edges. I forget what my final edge angle is, and I can't go by the lansky. I may have finished it up on the sharpmaker. Whatever, they are both nice and sharp! I'm going to leave my camp tramp as is.
 
There is an art to keeping a fine edge on a blade. I just don't have that skill. ;)

Lots of good information in this thread. :thumbup:
 
Everyone,
thanks for the input. I think Jeff hit it when he said, "I would guess that one of two things happened: First you just didn't sharpen long enough using the 400 grit for the amount of material that you needed to remove or Second you got impatient and started pressing too hard against that mouse pad and your 400 grit paper started to wrap around your edge and started to dull it."

I think I did the second one. I think I must have blunted the edge by pressing to hard into the mouse pad. Right now the edge is at Lansky 30 Degree. I will maybe look into reshaping it into a convex.

The current edge did fine field dressing my deer yesterday. I hammered that knife through the pelvis bone and tried to break it. I pryed and twisted and it did not just break. I had to hammer through 3 times (in line with each other) to get it open. I had the tip in the bone and was twisting it too. The edge up at the tip still looks great and is sharp!!! I really like the blade steel in this thing!!!!
 
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