Sharpening Frustration!

P

Prof. Ed

Joined
Jan 17, 2003
Messages
144
Hi all,
I just got a small Dempsey neck knife. Very thick spine and tanto shaped blade. It won't cut anything. Not even paracord. I'm a user, not a collector, so I sharpened it with the Spyderco System. It scratched the end of the blade some. Still won't cut. I used a Lansky ceramic stick, still won't cut. The point is the only thing that is sharp. I used my old razor strop, still won't cut. No use in carrying a necker, if it won't cut. Help I thought this thing would be like a razor! Boy was I wrong. I then tried some diamond sleeves that fit over my Spyderco ceramic triangles and guess what, still won't cut.
What can I do? I'm am doing a wonderful job of adding scatches to the tanto end
Your advice will be helpful. The only other sharpening stuff I have is a soft Washita Case Stone, full size and a little Hard Washita Case stone about three inches long. I stopped using these because the Spyderco system is supposed to be better and doesn't scratch as much. I'm disappointed. You guessed that.
Thanks,
Prof Ed
P.S. Mr. Depsey, I still like the knife, just need help.
 
First off, is it a chisel grind and if it is are you taking the burr off of the flat side or only sharpening the beveled side?
That will make a big difference, the edge rolls over when you sharpen it. You have to take the burr off the back edge with a fine stone to make it cut, stropping would work also.

Next, give us some specs on this knife. How thick is the blade, and how wide is it etc. This could just fall into the sharpened prybar category. Hard to figure sometimes, but some people are really into that. If it just isn't a good cutter, you might consider asking the maker to grind it a little thinner being a custom and all. I'm sure they'll do what they can to make the customer happy.

Does the edge seem dull with all the different tests? Shaving your arm (try at different angles,might have to be pretty steep), dragging across your thumbnail etc. ?

Not sure what else to tell you, hope things work out.
 
Hmmm
That just doesn't look like a very good cutter, small crowbar seems more like it.
It appears to have a very wedge like profile to the blade, really short bevels (distance from top of grind to cutting edge) and a thick blade. Looks like its at least 1/8" stock.
Personally I think a knife that size, and especially from stock that thick would be better off with a full flat grind to get a thinner profile, but to each his own.
See if all your sharpening has done anything for the edge by trying to shave the hair on your arm. You'll have to hold the blade at a much steeper angle than you would with a normal knife. There's a good chance you have the edge sharp but the blade binds too much for you to notice, or for it to cleanly slice paper or anything.

Dempsey is a member here on the forums, so I guess the best thing you could do would be to get in touch with him. He might be willing to grind the blade down thinner, or at least give you some tips for sharpening it.
 
Thank you Matt. Maybe Mr. Dempsey will see my post, or you could tell me where to move it so he will. I don't want him to think I don't like the knife, I do. But, as I said, I'm a user. Should I try the stones?:confused:
 
Have you read the Sharpening FAQ at this website? Try the magic marker trick.

I think the problem is the edge is ground to a pretty obtuse angle, and you're trying to grind it to a more acute angle with the Spyderco system. You can do that but it could take a long time -- longer than you've been working at it so far, maybe a lot longer.

The magic marker trick will show whether my guess is right or not. Coat the whole edge bevel with magic marker and make a few swipes along it. If there's still magic marker on it near the edge, you're not grinding that part yet.

If that's the problem you have two alternatives:

1) Sharpen to the angle it was made to. It might not be possible to do that with the Spyderco so you might have to resort to working freehand.

2) Regrind to a more acute angle. It might take so long to do that with the Spyderco you'd run out of patience, but you could use a coarse silicon carbide stone freehand to quickly get it to something close to the angle the Spyderco uses. Then and forever after you can sharpen it with the Spyderco.

Actually there's a third alternative:

3) Send it back to the maker and let him sharpen it for you. Most makers are happy to do that for a nominal fee; they don't want people running around saying their knives don't cut well. Search for his posts and see if he has an email address in his profile, or get in touch with him through the dealer. The only downside is you'll have to send the knife to him, and the advantage is you can be sure it won't get scratched -- he certainly knows how to sharpen without scratching up the blade.

I don't think the Washita stones are going to help you -- they're for polishing an edge after it's ground to shape, and if my guess is right it isn't ground to shape yet.
 
Hello Guys,
Thank you for your help. I have written David Dempsey.
I tried the Magic Marker trick. The bevel/ edge stayed black. With a diamond sleeve on the Sharpmaker it went away some. Cramped hands and it went away more. I still can't cut anything, not even a piece of parchment.
I went through the whole sharpening thing time and time again. Still the same.
That is my progress so far.:(
 
I have been in your position before . I have a Dozier Toothpick that when I first got it I couldn't sharpen it to save my life . I saw Bob at the Blade show and he ask me if I had figured out how to do it yet and I said no , so he gave me his method for shapening his HARD d2 and it has been easy ever since . I think we have all had at least one that threw us for a loop .

Jerry
 
Originally posted by Prof. Ed
Cramped hands ...
Click to expand...

I feel your pain.

The best thing I have found is to profile my knives on diamonds to the same angels as the Sharpmaker. From then on it's easy to maintain the edge using the Sharpmaker.

I've developed a home grown system of jigs and DMT stones to exactly duplicate the angle of the sharmaker and it works for me, but since I made it myself it's hard to reccomend to others.

Even with diamonds if the edge is obtuse enough it can be a a lot of work to thin them out. I just spent the last two nights reprofiling one 4" recurve blade, I'd say about 3 hours total. but now it's screaming sharp and can be maintained forever on my Sharpmaker.

The magic marker trick is by far the best method of checking your angles, everyone should be doing it ;)

Here's my Jig..

jig.jpg
 
Hi all,
Just talked with David Dempsey, a true gentleman. My knife is going home for a short visit. When it returns, it will have matured into all that it can be:D
Thank you all, again, for your good thoughts and help.
Warmest wishes,
Prof. Ed:)
 
Make sure the edge angle is reduced or you will have the exact same problem the next time it goes blunt.

The Sharpmaker is horrible for adjusting bevel angles, diamond sleeves or not. Use a large benchstone and some lapping compound or some really coarse sandpaper (80 grit or less).

-Cliff
 
Try my sistem,

Get two pieces of wood, one about 6-7 inches long, one about 2-3 inches long, 3/4-1 inch thich, 2-3 inches wide.

Make an inclined plane with long piece over short (like a ramp in an "L" shape) find a way to hold them temporarily as with a rubber band, duct tape, etc.

Lay a hone on the ramp, mark the edge of the blade with a magic marker.

Draw the knife horizontally on the hone, and check the angle, adjust the angle on the ramp until it fits to the angle on the edge of the knife.

Fix the two pieces of wood together (nails, glue, screws, whatever).

Measure the angle with a protractor, so that you can jig a hone at that angle by other means, such as fixing in a vise or raising one end of the sharpmaker.

Use your inclined plane to sharpen by drawing the knife horizontally over the hone or whatever you lay on it(ceramic rods, sandpaper, leather strop, etc.).
 
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