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bent tip repair

Mon Jun 02, 2014 1:14 am

Hi all,

I just received a new, amazing knife from CKTG. I haven't used it or taken it to the stones yet (waiting until I "earn" it after a big upcoming deadline), but I was admiring its beauty when I noticed that the last 10-15mm of the tip is just a hair bent. Very, very minor, and nothing too troubling given that it is hand-forged, but it is enough to see when holding the knife up vertically (it didn't notice it until "examining" the edge in front of a window). However, given the price of the knife, etc., I'm wondering about how easy this will be to fix if it turns out to annoy me over time or affects performance, or if it will actually require outside help to do it right, in which case I may consider exchanging it for another (I'd REALLY rather NOT, however).

The tip is carbon-clad Blue #2, heat-treated to about 62 give or take. Actually, the tip has virtually no cladding.

Any suggestions? Should I expect such a thin portion of the tip to level out on its own if I apply a little extra pressure while sharpening? Do I use a clamp to just press it flat? Would a "professional" just tap it with a soft mallet or bend it with force? I'm very curious how this is usually dealt with.


Re: bent tip repair

Mon Jun 02, 2014 2:52 am

I'm no expert like he is, but on Murray Carter's sharpening video he has a piece of wood with a slot, and showed how he would put the blade in, and bend it back. Think he gradually applied more pressure and checked until it was straight. It will probably be harder to sharpen with that bend.

Hopefully someone else who has experience straightening a blue #2 blade will chime in as well.

Do you have pics to help show the issue?

Re: bent tip repair

Mon Jun 02, 2014 3:36 am

I can't really get a decent picture of it. It is way too subtle, and is only really noticeable if you can move the knife and see how the tip shifts in relation to the spine as a whole. It does not look like a defect or an "accident" or damage in any sense at all, and the edge appears to be virtually perfect (and flexible enough at the tip that sharpening would not be effected in any real sense). I just looks like the knife might have been ground with more pressure on one side than the other, so it developed a slight bend or bias for the last few inches of the blade which is most obvious in the distal taper at the tip. We're talking hairs here—certainly less than 1mm overall. To me, it appears completely "natural" in a rustic sense. But I'm not used to dropping $400 on a hand-forged knife, and I want to make sure that any slight bends or biases are nothing to be concerned about in the long run, and are "fixable" if they do in fact seem to affect performance in any way. Thanks for the input and the video reference!

Re: bent tip repair

Mon Jun 02, 2014 2:36 pm

Joe, I've been looking more closely at all my knives and the videos knives lately for any bends/defects. My recommendation, if the bend is as minor as you describe, is simply use the knife and see if you feel that it's not cutting straight. If you're happy with the performance and don't feel any issues when using the knife - I'd leave it alone. It could be a minor grind issue, or a possible slight bend in the blade itself. If it's truly a grind issue, attempting to bend the knife "straight" could introduce effects you don't want.

If you look around at some recent threads, Melampus lined to a Murray Carter video on checking for blade straightness. Mark also has a video on straightening a knife blade. If you determine that you want to straighten the blade, go slow, take it easy, and check often for any changes. You DON'T want to go to far and over do it. Mark has posted that Takeda-san heats up blades in hot water to help pliability just a bit when straightening blades. I've tried it and I think it helps a little.

Re: bent tip repair

Mon Jun 02, 2014 2:54 pm

"and the edge appears to be virtually perfect"

You make this statement in your post above. What does this mean to you? That the edge looks straight without the apparent bend you can see from the spine? If so, I wouldn't worry about this bend at all.

If the edge bends slightly too.....well, it depends on how slightly as to what I'd do and/or recommend doing. It also depends on what knife, how thin the tip is, etc. You can bend back slight bends with light pressure.....but doing so can result in snapped off tips and what not. I'd echo Steve's thoughts....if it's minor enough not to notice....do nothing.

If the bend does affect performance....try bending it back ever so slightly. Over bend it the opposite direction and hold it there for a moment. After releasing, check.....keep doing until the bend is out.

Re: bent tip repair

Mon Jun 02, 2014 5:50 pm

Good advice above. You might be able to just ignore it.

If you do try to bend it back, I think the key is to start with less pressure than you need to make any changes. Then gradually do a bit more. The worst thing would be to bend it back too far on the first attempt.

Re: bent tip repair

Mon Jun 02, 2014 7:14 pm

If it is really minor with time you will sharpen it out.

Re: bent tip repair

Mon Jun 02, 2014 7:55 pm

Thanks for all the comments, guys. I'm glad I posted the question, as you addressed my biggest concern: this is easy to fix if necessary.

I did manage to take two pictures with better lighting outside today. Adam: I hope this will directly address your question, along with the following text, even though I could not get a direct edge shot:


The bend looks kinda like an uneven distal taper on the spine, but the effect on the edge is very minor at best. If you step back and look at the spine carefully, you can see a gentle bias towards the tip that increases for the very last bit. The best way to describe it, upon further reflection, is to say it is like an asymmetrical grind on an 80/20 blade: you'd expect the grind to be 50/50, but then you notice it is flatter on one side than the other. Here, the distal taper on the spine looks very consistent for most of the blade, but if you start to move it side to side (by rotating the handle) and focus on the consistency of the spine on one side and then the other, the distal taper starts to shift, and looks like it was done more on one side of the blade/edge than the other...and this effect appears most obviously towards the tip, and most aggressively in the last 10-15cm, where, at some angles, it actually looks like a slight bend in the spine. Like an asymmetrical edge, it does not appear to effect the actual edge in any real way. Weird, I know. It is like an optical illusion. From some angles, it looks straight, but I swear that at another angle, it looks bent by 1-2mm!! It changes based on whether you can see the zero grind side as the reference point, or if you can only see the "longer" or "curved" side as the primary focus point.

All of this comes from the simple fact that the variations in hand-made tools are expect and welcome, but can still prompt us to wonder. I'm sure I sound a bit weird in my posts above (perhaps even like a finicky idiot), but it is hard to judge the degree of such features without actually using the knife, and in the case of online stores like Mark's, it is always suggested that one make the decision to keep or exchange the product before, rather than after, use.

Anyways, I appreciate the serious and considerate feedback despite the ambiguity and unusual nature of my original posts.

Re: bent tip repair

Tue Jun 03, 2014 1:18 pm

Are both of those pictures from the spine? Or one from the spine, one from the edge? Or?!?!

Re: bent tip repair

Tue Jun 03, 2014 1:50 pm

They are both from the spine. One has the knife leaning slightly left, the other has the knife leaning slightly right. They are taken from the same camera position, etc.
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