Is this normal

M

MichalZ

Joined
Jun 3, 2020
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Hi guys

A bit confused so maybe someone can share their experience.

The other day I was cutting some paracord for garden project and after literally few cuts I noticed reflective spots on my blade....bit confused and disappointed....I grabbed few of my knives in different steels (3v, Aebl, 52100, k390) and started to use them.
Same effect.... literally after two or 3 push cuts through paracord edge gets dull🤯.

I sort of accept that nylon is abrasive but I wasn't expecting that effect even on high end steels.

I thought to myself, maybe it's the issue with my sharpening and I just got wire edges, but I used my spyderco k390 with still factory edge (apart of light stropping) and effect is the same.

Checked the paracord and it is heavy duty one but apart of that just the normal product.

Is that your experience as well?
 
Can't say I've ever had that happen from regular 550 cord. I've cut a ton of it over the years. My only guess is that the cord you have is unique somehow. They have some crazy different kinds of cordage out there. Dyneema core maybe? That stuff is ridiculously strong.
 
That's the one, it's stronger than regular 550, Its clean, no sand or dirt, cut it straight from the spool and on chopping board....effect is the same.

The outer layer has a bit plasticy feel, maybe that's the issue
Screenshot_2024-06-02-11-13-30-51_b5f6883d2c20a96c53babc0b4ac88108.jpg
 
MichalZ said:
maybe it's the issue with my sharpening and I just got wire edges
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Sharpen your knife as usually and then carve some pine or similar wood across entire edge.
If the knife won't cut news print cross grain after that there was some sort of a burr on the edge.
I used to test my edges on spruce wood but lately switched to oak wood.

MichalZ said:
but I used my spyderco k390 with still factory edge (apart of light stropping) and effect is the same.
Click to expand...
Who says there can't be a burr on Spyderco factory edge?

Here is an excelent video explaining your problem. I think you should watch it. If nothing else this video is very interesting.
 
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I’ve heard of paracords that have a fuse strand or copper wire in the core, I’d expect that could dull an edge. Regular 550 I’ve cut a lot with no issues, and recently the HD cord as well.

Parker
 
That was a nice burr video that TheOne45 linked to. Burrs are more common tha people think. I don't know if that's the OP's problem, but it could be.

The guy in the video removes burrs with lots and lots of long sharpening strokes on the full length of the stone. To remove the burr, he lightens the pressure gradually until he's barely touching the stone.

A quicker way to remove the burr is to shorten the length of the sharpening stroke to just an eighth or quarter inch. With the burr leaning off to one side, you can cut it off quickly. Continuing the sharpening stroke after that just raises a new burr.
 
Twindog said:
The guy in the video removes burrs with lots and lots of long sharpening strokes on the full length of the stone. To remove the burr, he lightens the pressure gradually until he's barely touching the stone.
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Nope.
He just reduces the burr with light passes as much as he can.
Then he removes the burr with a strop.
 
I've had such an issue with burrs that I've just started to micro bevel them off.
 
TheOne45 said:
Nope.
He just reduces the burr with light passes as much as he can.
Then he removes the burr with a strop.
Click to expand...
He uses 6 micron diamond paste for first stropping, with lots of long strokes, which is aggressive sharpening. And he minimizes the burr with stones the same way.

He acknowledges that long strokes reproduce the burr, so he gradually reduces that burr recreation with lots of strokes using lighter and lighter pressure.

I've found that you can achieve similar results -- faster and with less metal removal -- with shorter strokes.

You can reduce burr formation by using finer grits, lighter pressure or shorter strokes. Or all three. I use all three, but like shorter strokes the best.
 
MichalZ said:
The other day I was cutting some paracord for garden project and after literally few cuts I noticed reflective spots on my blade....bit confused and disappointed....I grabbed few of my knives in different steels (3v, Aebl, 52100, k390) and started to use them.
Same effect.... literally after two or 3 push cuts through paracord edge gets dull🤯.
Click to expand...

Since your question in the title was "Is this normal?", my answer would be "no". Just a few cuts should not be damaging your edge like that.

MichalZ said:
I thought to myself, maybe it's the issue with my sharpening and I just got wire edges
Click to expand...

That would be my first guess too.

One way I like to remove a burr is by using gentle edge trailing strokes on a ceramic stone. This will take care of even the most stubborn burr, as it will eventually wear itself down until it is gone, as opposed to the usual method of just ripping the burr off with stropping, which can actually harm the edge and give you worse performance.

Another good tip is to push your thumb over both sides of the edge in a direction away from the apex, to feel for a burr. If you do it right then there is absolutely no possibility of cutting yourself, and it's a really simple way to check for a burr. An edge with no burr will feel smoothly uniform all the way to the apex. If there is a burr then you will feel a rough lip at the apex, often on only one side. That's why you have to feel both sides. And make sure to check the entire edge. Sometimes you will have a burr in only one section, so you need to check the whole thing.
 
Guy McVer said:
One way I like to remove a burr is by using gentle edge trailing strokes on a ceramic stone. This will take care of even the most stubborn burr, as it will eventually wear itself down until it is gone, as opposed to the usual method of just ripping the burr off with stropping, which can actually harm the edge and give you worse performance.
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Why would a strop rip off the burr? You are doing the same motion on a strop as on the stone except the strop is a far gentler medium. That's why it is an effective tool for final burr removal.

Also you can have a small burr that is almost impossible to feel by your fingertips. Just because you can't feel it, doesn't mean you have completely removed the burr. Personally I think that assumption is why many people struggle with certain steels performing worse than their expectations.
 
chalby said:
Why would a strop rip off the burr? You are doing the same motion on a strop as on the stone except the strop is a far gentler medium. That's why it is an effective tool for final burr removal.
Click to expand...

The strop is doing two things differently than a ceramic stone or ceramic hone.

1. The strop is wrapping around the apex.

2. The strop is "grabbing" or gripping the surface of the edge in a way that the stone can't.

Different materials, different behaviors. Different results. Especially if you use compound on the strop, it will convex your edge. The ceramic will not do that. If your goal is to have a curved edge, that's fine.
 
Guy McVer said:
The strop is doing two things differently than a ceramic stone or ceramic hone.

1. The strop is wrapping around the apex.

2. The strop is "grabbing" or gripping the surface of the edge in a way that the stone can't.

Different materials, different behaviors. Different results. Especially if you use compound on the strop, it will convex your edge. The ceramic will not do that. If your goal is to have a curved edge, that's fine.
Click to expand...
I don't know what you mean by gripping the edge. You will generally get a very small micro-convexed apex, but this isn't normally a negative to performance.

If used correctly a strop will only refine your edge. Obviously this isn't always desirable eg. if you want to keep a toothy edge.
 
chalby said:
I don't know what you mean by gripping the edge.
Click to expand...

Imagine how a piece of rubber grips a flat smooth surface when pressure is applied. Similar concept. When you apply pressure to the stop with the knife, there is a certain amount of grip to overcome. And depending on your strop, or what side you're using, it will have little fibers as well, which also grab onto the surface of the edge. This is why stropping without compound with just a few swipes can restore cutting performance by removing debris which was previously clogging the edge. You can see it for yourself whenever you give your knife a couple of quick swipes on your pants leg.
 
Guy McVer said:
Imagine how a piece of rubber grips a flat smooth surface when pressure is applied. Similar concept. When you apply pressure to the stop with the knife, there is a certain amount of grip to overcome. And depending on your strop, or what side you're using, it will have little fibers as well, which also grab onto the surface of the edge. This is why stropping without compound with just a few swipes can restore cutting performance by removing debris which was previously clogging the edge. You can see it for yourself whenever you give your knife a couple of quick swipes on your pants leg.
Click to expand...
You may be right, but I suspect what is really happening is not what you are imagining.
 
You mentioned "reflective" spots appearing on your blade. Is this the "reflective" variety of paracord? If so, it is not "normal" paracord. Reflective thread is often woven with microscopic reflective elements such as glass beads or micro prisms, and this specialized thread illuminates when exposed to light sources, reflecting brilliance toward its origin. Check the product label or product page to find out for sure.
 
The paracord has reflective thread ....when I used term reflective in relation to edge I meant the blunt spots that reflect the light
 
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