Issue Re-Profiling Coping Blade on Congress

[LaughingBones]

It's been a full weekend of mess ups and hours of sharpening. I posted yesterday about a Whittler I was re-profiling and with the advice from Obsessed with Edges and Spey I was able to do it and it was a great feeling. I'm very new to sharpening and am fascinated with the history and the self reliance of of being able to sharpen a knife.

I've got a Boker Congres that is possibly my favorite knife and plan to do some whittling when it warms up a bit. I wanted to reprofile the small blades down to 30 inclusive for maximum efficiency while doing so. They both seemed to be over 40 inclusive. First off the grinds on all blades of the knife ride higher on one side. I was able to complete the pen blade, but holy crap, this coping blade has been a headache. I've spent hours today sharpening. I've been using the sharpie trick and I am at a point where I'm removing the sharpie on the edge on both sides completely, but it's still dull!! i can not for the life of me figure out why. My current set up is the sharpmaker with 150 grit sandpaper I've strapped to the SM, which worked good to help reprofile. Does anyone have any advice? Should I keep going or seek a professional. I'm worried about permantley ruining the blade.

 

[Rey HRH]

When you've removed all the sharpie off on one side, have you raised a burr on the other side?

How thick is the shoulder? I'm not familiar with the knife you have so I don't know the blade geometry.

 

[LaughingBones]

When you've removed all the sharpie off on one side, have you raised a burr on the other side?

How thick is the shoulder? I'm not familiar with the knife you have so I don't know the blade geometry.

Thanks for you reply!! I actually just go back and forth, so I havn't seen a burr, but I was reading about doing that. That's my next step. Do you think the 150 grit sandpaper is efficient for Boker Carbon Steel?

 

[Philbird]

Thanks for you reply!! I actually just go back and forth, so I havn't seen a burr, but I was reading about doing that. That's my next step. Do you think the 150 grit sandpaper is efficient for Boker Carbon Steel?

I think sandpaper will work, Boker C-75 isn't exactly ZDP-189, it's a closer relative of 1095. That being said, 150 seems a tad coarse. You might want to start with something a little higher up, to minimize blade loss.

 

[Obsessed with Edges]

Thanks for you reply!! I actually just go back and forth, so I havn't seen a burr, but I was reading about doing that. That's my next step. Do you think the 150 grit sandpaper is efficient for Boker Carbon Steel?

150 is too coarse; with simple carbon steel on a small blade like that, I wouldn't go any lower than ~320 or so (wet/dry sandpaper), for reprofiling. Also, if the sandpaper isn't firmly held in place, and it lifts, rolls or moves at all under the edge, that'll make it very hard to keep the apex crisp, especially if using edge-leading strokes. This could likely be why you're not seeing a burr, because the apex will round over as the paper is moving/curling around it. The sandpaper will work a lot better, much like a stone, if it's tacked down with some temporary adhesive, double-sided tape (not the foam-backed type, it's too soft) or other similar means. When the paper can't lift, curl or move under the edge, the apex produced will be much, much crisper; and as a bonus, it'll also work more aggressively (faster), more like a stone of the same grit.


David

 

[LaughingBones]

Thanks guys! Really good info. Glad I asked about the 150 grit sandpaper. I was just about to start again. I really hope I didn't run the blade. I'll stop and grab some 320 tomorrow. It's really upsetting having these issues. I'll keep working on it. The edge looks terrible right now.

OBE,
Do you mean stick the sand paper to the sharpmaker rod or something else?

 

[Rey HRH]

I've been using the sharpie trick and I am at a point where I'm removing the sharpie on the edge on both sides completely, but it's still dull!! i can not for the life of me figure out why. My current set up is the sharpmaker with 150 grit sandpaper I've strapped to the SM, which worked good to help reprofile. Does anyone have any advice? Should I keep going or seek a professional. I'm worried about permantley ruining the blade.

I'm not trying to be a know-it-all since I don't. But I just want to make sure the basics are covered.

1) How are you setting the 15 degree angle? Or how do you know you're holding the blade at a 15 degree angle?

2) You say you're removing the sharpie on the edge on both sides completely. But when you're re-profiling to a new more accute angle and you're already at the point of removing the sharpie on the edge, that means you've already reprofiled to the target angle and that you should be removing the sharpie across the whole bevel instead of just the edge, right?

Good luck.

 

[Obsessed with Edges]

Thanks guys! Really good info. Glad I asked about the 150 grit sandpaper. I was just about to start again. I really hope I didn't run the blade. I'll stop and grab some 320 tomorrow. It's really upsetting having these issues. I'll keep working on it. The edge looks terrible right now.

OBE,
Do you mean stick the sand paper to the sharpmaker rod or something else?

Yes, to the rods, if the SM is what you prefer to use with it. I like using glass or stone (smooth & flat) with sandpaper, and I use a spray adhesive for that. I use DAP Weldwood Multipurpose Spray Adhesive, which allows temporary bonding. I spray the back of the sandpaper, and NOT the surface on which it's used. Give it ~10-15 minutes to get 'tacky' on the back of the paper, then just stick it in place. It's strong enough to hold the paper in place on the surface used (I've done this on wood, glass and granite), and yet will allow it to be peeled off when done with it, or when/if the paper wears out and needs replacing. When it's peeled off, any traces of the adhesive left on the smooth surface can be cleaned off with mineral spirits, isopropyl alcohol or perhaps even some Windex. It's not difficult to clean up, if you're concerned about it contaminating the surface of your rods. If using the SM's rods, use the white ones (Fine/UF); their smoother surface will clean up that much easier.

(I always use edge-trailing 'stropping' strokes with sandpaper, BTW)


David

 

[LaughingBones]

I'm not trying to be a know-it-all since I don't. But I just want to make sure the basics are covered.

1) How are you setting the 15 degree angle? Or how do you know you're holding the blade at a 15 degree angle?

2) You say you're removing the sharpie on the edge on both sides completely. But when you're re-profiling to a new more accute angle and you're already at the point of removing the sharpie on the edge, that means you've already reprofiled to the target angle and that you should be removing the sharpie across the whole bevel instead of just the edge, right?

Good luck.

Thanks for the reply brother!
1. I'm setting the angle using the Sharpmaker

2. I'm removing the the whole sharpie from the bevel.

I'm gonna work on it a little more today. It may be one of those things where I'm very close and just hav'nt got there yet.

OWE!
Thanks for the tips!

P.S. With this coping blade the very top of the blade is moldied to the left which is weird. It kind of waves out. I've seen other Congress's that have had the same blade style. This style makes it harder to estimate the right angle while using the SM.