help with sharpening pls

spyken · May 17, 2002

hi, can someone offer me help with sharpening? I recently acquired the sharpmaker 204 and tried to sharpen the PE portion of my CQC7 chisel ground blade...but I have the following problems:

(1) can't get shaving sharp edge (I'm using the 40deg slots). I have reprofiled the edge after spending hours.

(2) even if it shaves a little (I do my sharpening at 1am in the morning), the shaving edge is gone by 12pm the next day.

(3) the grind lines are uneven.

Help. I managed to sharpen another SE blade fine but cant seem to get my PE blades razor sharp.

Would be nice if Joe Talmadge could offer some advice?

Also, do I need to sharpen one side with the ceramic sticks until I get a burr (very difficult to do) before I stroke it off lightly the other side (since it's a chisel ground blade)...I'm having great difficulty raising a burr with the ceramic sticks....

Pls help

thanks much.

Joe Talmadge · May 17, 2002

spyken:

The problem is that you're using a chisel-ground blade. If you actually reprofiled the one side to 20 degrees, then the other side would be 0 degrees, leaving a total of a 20 degree edge. It is extraordinarily unlikely the steel in the CQC-7 can even remotely hold up to any kind of use at that angle. The CQC-7 is typically sharpened more to around 30 degrees (30 degrees one side, 0 degrees the other side). It will readily burr over and take to regular sharpening methods at that angle. The spyderco 40 degree slots are more aimed at a heavy-duty utility edge for a "regular grind" blade -- that is, 20 degrees on each side, for a total of 40 degrees. The 30 degree slots are the very lowest I would go for a steel like ATS-34/154-CM. But that's 30 degrees total, and right now you're putting 20 degrees total on your chisel blade.

I don't have any first-hand experience in trying to sharpen a chisel-ground blade to 30 degrees on the sharpmaker. Anyone have any ideas? Here's one kind of goofy idea. If you put the sticks in the 30 degree slots, then tilt one side of the sharpmaker until one of the sticks is exactly vertical, then the other stick will be exactly 30 degrees off vertical. if you prop the sharpmaker at that angle, you'll be able to use the standard sharpmaker technique (keep the spine vertical) and you'll get that 30 degree angle. Here's another idea: put the sticks in the 30 degree slots, and put the knife on the sharpmaker as if you were going to sharpen it, with the spine vertical. The angle between the stick and the knife is 15 degrees. Try to double the angle just by eyeballing it, by tilting the spine away from the stone. That's 30 degrees. Unfortunately, now you have to hold the angle by hand, but it will be easier than using a benchstone because you can use sight as well as touch to keep the angle consistent.

OR, get a sharpener that has a 30 degree angle preset.

Joe

spyken · May 17, 2002

Joe,
Thanks much! I'm terrible at sharpening (which is why I bought the sharpmaker) so your idea at holding the angle by hand would surely kill me

I can only sharpen the CQC7 with my Edgepro (super sharp - but I still need to refine my technique to get it hair poppin sharp).

Pls Joe, how do I get the edge shaving or hair popping sharp (I've read your FAQ) but can't seem to get it so. I know I sharpen the edge until I get a burr, then sharpen the other side until I get another burr the original side, then cross over, and over until as little burr forms. Is this correct? But on the sharpmaker instructions, it's one stroke on one side, then the other side w/o mentioning whether you need to raise a burr. (I don't have a VCR so haven't watched the video). Have I gotten it correct? Does anyone have any comments for me?

Or, is stropping with paste the only way to get a razor sharp edge (I don't have a leather strop or paste - I only have the back of a legal pad)?

Thanks much.

Joe, if you're replying, what do you think of D2 steel that BM uses on some of their blades, as compared with VG10 or 154CM (I know I asked this on anor thread)? Thanks.

Joe Talmadge · May 19, 2002

spyken:

You're right, there's a difference between the way I recommend sharpening, and the way Spyderco does. Sal and I have discussed this before, and while we both feel the other one's method is valid, we also disagree about which one should be taught first, at least on the sharpmaker. In all fairness, I have seen at least one occasion where someone had problems with the burr method, switched to Spyderco's method, and then got better results. On the other hand, there are some reasons to go with the burr method. First of all, I don't think there's a professional knife maker in the world who uses anything but the burr method. Second, the burr method gives you equal sharpness along the entire edge. No matter how sharp you get with the every-other-stroke method, you will never have a guarantee that the entire length of the edge is equally sharp -- in fact, it's normal to have sharper and less sharp parts that way. I've come around to thinking that the burr method takes just a tad more skill, but once it's mastered, it definitely gives better results. But for some people who just can't get it, the other method works better.

Phew! Ookay, on to stropping. STropping is definitely not the only way to get a razor sharp edge. A strop is just the last step in a progression of ever-finer hones. I find that Spyderco's new ultra-fine hones gives an absolutely killer edge, and I feel they are well-worth the price if you'll looking for a razor-polished edge. If you do you sharpening job right on the ultra-fine hone, a strop will just give a small marginal improvement.

Okay, on D2 versus 154-CM or VG-10, D-2 beats out 154-CM and VG-10 on all performance measures except for stain resistance. D-2 won't rust like, say, O-1, but it certainly will rust, it is not stainless. Worse yet, if you get a Benchmade D-2 blade, they cover it with that black slop that they call BT2. On the other hand, D-2's performance should be wonderful, if Benchmade did their D-2 heat treat right (I don't have one yet). I plan to own an axis AFCK w/ D-2 someday, but I'm holding out a few more months in the hope they'll look at boron carbide, which I'm impressed with on my Kershaw Chive. On the other hand, I don't know how well boron carbide protects against rust, whereas I know BT2 is very effective.

Joe

spyken · May 19, 2002

Joe,
Thanks a lot! You're the best!!! I guess I will also hold on before buying the AFCK II with the BT2 coating, for now....
Spyken