Why is it so hard to sharpen Kershaw launch 4?

[averagejoebro]

So I have a Kershaw launch 4 and I also have a work sharp guided field sharpener. I have been going to town on the Kershaw with the coarse, fine Diamond stones, ceramic honing rod and the leather strop on the work sharp. It seems like no matter how hard I try I just can’t get the Kershaw very sharp. It hardly cuts through paper. I used the work sharp on a kitchen knife and I got it paper slicing sharp (but not hair shaving sharp). What’s the trick to getting knives hair shaving sharp? I thought it was using a ceramic honing rod and a leather strop but apparently that’s not it. Does the Kershaw launch 4 just have a really weird shaped blade or something? Any advice?

 

[ms3902]

I picked up a work sharp field sharpener a little while back and was surprised at how well it works, I still prefer to do it free hand but I needed an "all in one" solution for a camping kit. I have been able to get hair shaving sharp with the work sharp without too much hassle. Two things I would recommend, 1) don't use too much pressure when sharpening, I try to just use the weight of the knife if at all possible, it makes a huge difference. 2) cover your edge with a sharpie before you start to sharpen your knife to make sure that you are hitting the apex of the edge. Your Kershaw may be sharpened at a steeper angle than what your sharpener is, which would keep you from sharpening the apex of the edge.

 

[bikerector]

So I have a Kershaw launch 4 and I also have a work sharp guided field sharpener. I have been going to town on the Kershaw with the coarse, fine Diamond stones, ceramic honing rod and the leather strop on the work sharp. It seems like no matter how hard I try I just can’t get the Kershaw very sharp. It hardly cuts through paper. I used the work sharp on a kitchen knife and I got it paper slicing sharp (but not hair shaving sharp). What’s the trick to getting knives hair shaving sharp? I thought it was using a ceramic honing rod and a leather strop but apparently that’s not it. Does the Kershaw launch 4 just have a really weird shaped blade or something? Any advice?

The kitchen knife is very likely softer and the sides of the edge are sharpened to meet each other faster.

I suspect you aren't forming a new edge yet if the knife isn't cutting. Spend more time with the course stone so the edge bevel is sharpend it's full height. A marker on the edge makes this easier to visualize. Many new people, myself included, don't get a sharp edge with the course stones before progressing to the next finer stone, especially when we 1st get into some of the higher carbide steel. 154cm isn't the hardest to sharpen, but it's will likely take a fair bit longer than most kitchen knives.

Kitchen knives, as least all of the production ones I've had, tend to be really soft and very easy to sharpen. The Japanese knives tend to be harder heat treat, but none of the rest I've seen have been.

Summary, spend more time with the coarse stone. It's the real work horse of the sharpening arsenal. The rest make it sharper but you should be able to form a working edge, and probably a little ragged, on the course stone 1st.

 

[Sharpoholic]

The biggest mistake beginners make is not forming a bur. If you don’t form a bur on your coarsest stone, no amount of further progression will make a knife sharp. I suggest taking some time using a coarse stone on a cheap knife to really get practice knowing what a bur feels like. Each steel will be different

 

[shane45-1911]

Assuming your sharpening technique is solid per the advice above, some knives simply will not get sharp because of poor heat treatment.

I've had knives that no matter how long I try, or how good the sharpening technique, the edge will not apex. It is like trying to sharpen Jello. The edge just keeps flip-flopping from side to side because it is so soft, even with fine stones and a light touch and a relatively obtuse DPS angle.

 

[Robert Ptacek]

My guess it is not fully apexed.

 

[averagejoebro]

Thank you guys for the info. I will give it more time on the coarse stone. I saw another guy here got his Kershaw launch hair shaving sharp so I’m hopeful I can get there too. I will get it to a good burr first and make sure it’s apexed.

 

[awesome14]

So I have a Kershaw launch 4 and I also have a work sharp guided field sharpener. I have been going to town on the Kershaw with the coarse, fine Diamond stones, ceramic honing rod and the leather strop on the work sharp. It seems like no matter how hard I try I just can’t get the Kershaw very sharp. It hardly cuts through paper. I used the work sharp on a kitchen knife and I got it paper slicing sharp (but not hair shaving sharp). What’s the trick to getting knives hair shaving sharp? I thought it was using a ceramic honing rod and a leather strop but apparently that’s not it. Does the Kershaw launch 4 just have a really weird shaped blade or something? Any advice?

Two things prevent shaving sharp. Assuming you've got it pretty sharp, only draw the blade across the sharpener, don't push the edge into it. After you finish with one grit, tip the angle up and take off the burr before the next grit. On your final grit, when you're done sharpening, tip the angle up to about 45 degrees, and take the burr off. Be very slow about removing the burr, so you can get a feel for it. There's a lot of material available on removing a burr.

 

[bikerector]

Two things prevent shaving sharp. Assuming you've got it pretty sharp, only draw the blade across the sharpener, don't push the edge into it. After you finish with one grit, tip the angle up and take off the burr before the next grit. On your final grit, when you're done sharpening, tip the angle up to about 45 degrees, and take the burr off. Be very slow about removing the burr, so you can get a feel for it. There's a lot of material available on removing a burr.

Pushing the edge into the stone is fine. Many guys go both directions, draw and push, as it's faster. Drawing does help with the bur removal, IMO.

I also like to increase the angle to make sure the burr is gone, but I just wait until the end. I then follow with a few light strokes at the original angle.

 

[awesome14]

Pushing the edge into the stone is fine. Many guys go both directions, draw and push, as it's faster. Drawing does help with the bur removal, IMO.

I also like to increase the angle to make sure the burr is gone, but I just wait until the end. I then follow with a few light strokes at the original angle.

I'll have to try that. I generally don't get knives dull enough to warrant pushing into the grit. Although, I often do with other people's, or it would take forever!