Help me learn to strop... or not

ncrockclimb

ncrockclimb

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Nov 20, 2014
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Let me preface this by saying that although I am a rather new knife enthusiast. I got my first "real" knife (Benchmade Griptilian) about two years ago, and since then I have spent way to much money on blades and time on this (and a few other knife related) forum.

I have worked hard to learn how to sharpen my own knives, and have become rather proficient with the Sharpmaker. I can get my knives shaving sharp without much difficulty. I have had Josh (Razor Edge Knives) put some awesome mirror edges on a few of my blades, and I have no problem maintaing his super sharp edges with the "fine" and "super fine" Sharpmaker rods. As long as the blade is not too obtuse for the Sharpmaker to reach the edge, I have found it to be all I really need for my folding knives.

Recently, I have begun buying fixed blades. Although I can sharpen them on my Sharpmaker, it is somewhat awkward to use it with my BK9. Also, I would like to maintain the convex edge found on a few of my fixed blades, and that is something I cannot do with the Sharpmaker. So, long story short, I am thinking about expanding my sharpening skill set to include using a leather strop.

I have done a search, but I finding a lot of the stuff I read to be rather confusing. With that in mind, I have a few questions:

- do folks use a different strop for each compound, or just rub one compound on top of the old?
- is it necessary to use a compound on a leather strop?
- do you need to supplement stropping with sharpening on a stone?
- should I just forget about the strop and get a set of stones? (loaded question, but I figured I would ask)

If you could recommend a source like "Stropping for Dummies," I would really appreciate it. When I was learning to use my Sharpmaker, I watched Sal's video and found a few very informative videos and threads that allowed me to go from neophyte to competent in a very short time. I have not found similar resources for stropping... but that could be because I am looking in the right place.

Thanks for taking the time to read. I really appreciate any help you can provide me with as I lear to strop.
 
- do folks use a different strop for each compound, or just rub one compound on top of the old?
Yes, even with the most rigorous cleaning there will still be some residual abrasive , you must use a different strop for each abrasive

- is it necessary to use a compound on a leather strop?
No , theres a wide variety of stropping substrates , leathers, woods, paper over glass

- do you need to supplement stropping with sharpening on a stone?
Yes and no. It depends on several factors. How dulled the knife is , and what stropping compounds you have available to you. I sharpened a ceramic knife start to finish once with nothing but a series of strops loaded with compounds , going from coarse (160ish grit) to much finer(around 160,000 grit). But generally speaking you should start out on stones and move to strops as a final step or when you get to steps finer than a waterstone can go.

- should I just forget about the strop and get a set of stones? (loaded question, but I figured I would ask)
Its up to you, there are people who use nothing but strops to sharpen their knives , dropping down to coarse sandpaper only when absolutely necessary (this is getting more popular in the scandi/convex crowds) with high quality compounds being more readily available you can go all the way from 160grit (and coarser) to as fine as you really want. But realistically for most people starting with a few waterstones and finishing with a strop or two with progressively finer compounds is more efficient and economical.
For example , a 400,1k,2k,4k Nubatama progression finished off on some 2u and 1u compound (Boron Carbide or Cubic Boron Nitride depending on the steel, on your choice of substrate) is a fairly economical progression , that will tackle most steels and leave you a clean scratch pattern at a fine finish. You can always stop sooner/coarser , or add more/finer compounds and strops as desired.

More than anything you need to know that unless you plan on intentionally convexing your edges that you need to be using hard substrates. Paper on glass, hardwoods, Kangaroo Leather, Nanocloth.
 
Well stated responses Sadden. Saved me a lot of typing. :) Heed the statement about convexing your edges and using hard substrates ncrockclimb.
 
ncrockclimb said:
Let me preface this by saying that although I am a rather new knife enthusiast. I got my first "real" knife (Benchmade Griptilian) about two years ago, and since then I have spent way to much money on blades and time on this (and a few other knife related) forum.

I have worked hard to learn how to sharpen my own knives, and have become rather proficient with the Sharpmaker. I can get my knives shaving sharp without much difficulty. I have had Josh (Razor Edge Knives) put some awesome mirror edges on a few of my blades, and I have no problem maintaing his super sharp edges with the "fine" and "super fine" Sharpmaker rods. As long as the blade is not too obtuse for the Sharpmaker to reach the edge, I have found it to be all I really need for my folding knives.

Recently, I have begun buying fixed blades. Although I can sharpen them on my Sharpmaker, it is somewhat awkward to use it with my BK9. Also, I would like to maintain the convex edge found on a few of my fixed blades, and that is something I cannot do with the Sharpmaker. So, long story short, I am thinking about expanding my sharpening skill set to include using a leather strop.

I have done a search, but I finding a lot of the stuff I read to be rather confusing. With that in mind, I have a few questions:

- do folks use a different strop for each compound, or just rub one compound on top of the old?
- is it necessary to use a compound on a leather strop?
- do you need to supplement stropping with sharpening on a stone?
- should I just forget about the strop and get a set of stones? (loaded question, but I figured I would ask)

If you could recommend a source like "Stropping for Dummies," I would really appreciate it. When I was learning to use my Sharpmaker, I watched Sal's video and found a few very informative videos and threads that allowed me to go from neophyte to competent in a very short time. I have not found similar resources for stropping... but that could be because I am looking in the right place.

Thanks for taking the time to read. I really appreciate any help you can provide me with as I lear to strop.
Click to expand...

Convex and V grind edges are two different things requiring two different types of strops. Well, not really requiring, but different types of strops make you goals easier to obtain.

Stropping is just a way to straighten a rolled edge, remove metal bits left over after stones, or going into grit territory where stones cannot go. Keep that in mind.

For normal V grinds a very firm strop with a very hard backing works best. If you use a soft strop it'll roll your edge and dull it.

For convex grinds you'll want a softer strop that conforms to the convex edge.

You can do convex edges with a hard strop and you can do V edges with a soft strop but it takes more time and care and attention to make sure you're doing what you're supposed to be doing: cleaning up your edge apex without dulling it.

So depending on what you want to do with a strop will dictate what you use on a strop, if anything. If all you want to do is light realignment of a soft steel, like a straight razor, then all you really need is plain leather. If you just want to remove the bits of leftover metal after using stones, again, all you need is leather. If you want to refine your edge to a grit level where stones can't go, or the cost of the higher grit stones is prohibitive, then you'll need some kind of appropriate stropping medium that holds the strop compound you choose.

Strops don't need to be leather, they can be made of almost anything that works. Denim, glass, wood, cardboard, whatever. As long as they're not inherently coarser than what you desire and you can run a blade on it in a edge trailing (spine leading) manner you can use whatever you want. If all you want to do is remove some small bits of metal you can use your hand or jeans if you want. It can be done.

When you get into different compounds is when you really kind of need to start being more picky about what you use, and that's really only if you care about the finished polish of the edge. You want to make sure the stropping medium is finer than whatever grit compound you use. When you get up into super high grit compounds, think like 50,000 grit and above, you need some super fine strop medium so that the medium itself doesn't leave scratches that the compound cannot polish out. Think kangaroo hide and whatnot.

But yeah, you need different strops for different compounds unless you're taking a strop with a fine compound and putting coarser compound on top of it. But you cannot go the other way.

I use thin cardboard on a wood backing. I don't need to worry about cleaning, I use them until they're loaded with metal and then throw then away and make another one, they last a good long time. I only go up to 14k grit. If I was going higher then I'd probably buy a cheap bed sheet set and cut up what I need and use some 3M adhesive spray to stick them on my wood paddles. And since I only have V edges, then those strops work for me.

Since you want to maintain a convex grind edge, you'll need something different. A lot of people recommend mouse pads as a backing with some pliable strop medium on top of it, like some kind of paper or denim or linen loaded with the compound. I cannot speak to that, though, but many people with more experience than me recommend it.
 
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I'll just add one thing, in that you don't need a softer strop (or soft anything) for convexing. The natural stropping motion of the hands will still create or enhance a convex, and a firmer/hard backing will keep the edge crisper in the process. There's a natural tendency for the hands (therefore the blade) to rock slightly from a low angle to a slightly higher angle during a stropping stroke. In practicing with this on sandpaper (over hard backing), just let it happen, and watch closely what it does to the shape of the bevels. With a fairly aggressive strop compound that removes metal quickly (as on a strop which blackens very fast), convexing is very easy on a hard strop; almost inevitable, in fact. And on hard stones/hones, a back & forth 'scrubbing' motion while grinding can also create a convex; it's essentially how I create mine, and I finish off as mentioned above with a wood strop and aggressive, but still relatively fine, compound (I use 3/1µ diamond, or white rouge works well also).

The apex of the edge will always be crisper when created and maintained on firm/hard hones and strops. The key in using them, is to keep the natural 'rocking' angle variation BEHIND the apex, and don't allow it to quite touch the apex or go beyond it.

It's generally easier for a beginner to create a convexed bevel on a soft backing, like sandpaper over leather; and if that's just used for the sake of establishing the shape of the bevels behind the apex, that's fine. But for the sake of the edge apex itself, honing & stropping will always leave it crisper when it's done on something very firm.


David
 
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I'll toss another thought on the pile too -

Sharpie, its not just for stone work. The level of useful feedback on most strops is slight to non existent. You can use a Sharpie to color the edge and see just what's going on per pass.
On broad or full convex and scandi edges you can make a series of lines from spine to edge and find out exactly where you're making contact.

One of the reasons it is more difficult to find a definitive treatise on stropping is because there is a much larger number of variables one can introduce compared to stone work. Go slow, use the Sharpie.
 
I'd attempted to add this to my earlier post yesterday, in illustrating that a convex can be done on firm/hard media. The editor or vBulletin software keeps choking on it and wouldn't accept the edits to that post. For some equally confounding reason though, it will accept it as a separate post. So, here goes...

The pics below are of the spey (reground to a spear/drop-point, BTW) and sheepsfoot blades on my Buck 301 stockman. I thinned the edge and established the convex with a back/forth scrubbing motion on diamond hones (to full apex), then finished & polished on a hard denim strop (over a red oak block) with white rouge. I've also done essentially the same to S30V, D2 (C.R.K. Sebenza and Queen blades) or other high-wear steels, by substituting a wood-only strop (basswood or balsa) with diamond compound.


David
 
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David that is REALLY nice looking work. You guys are light years ahead of me on sharpening.....and I thought I was something!!!! Set back a few pegs I am!!! Great work! Learning A LOT from you.
 
samuraistuart said:
David that is REALLY nice looking work. You guys are light years ahead of me on sharpening.....and I thought I was something!!!! Set back a few pegs I am!!! Great work! Learning A LOT from you.
Click to expand...

Thanks Stuart. That project made me pretty happy. I've learned a ton from many others here as well, and feel like whatever I've accomplished has been 'on the shoulders of giants', as the expression goes. For example, the back/forth scrubbing motion on diamond hones that I mentioned, I sort of attribute that to (and try to emulate) the technique I've seen Jason B. use in many of his videos here (Thanks to Jason, BTW :thumbup: ).


David
 
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