Life on the Edge: The Importance of Blade Maintenance, by Dr. DAC

Most of us use a cutting edge every single day, be it a chef’s knife, pocket knife, or scissors.  We typically suffer with overly dull cutting surfaces, and that is OK for cutting a zucchini after the daily nine-to-five routine.  However, when faced with a long-term survival situation, the importance of cutting edges will skyrocket, quickly shifting this humdrum facet of daily life to center stage.  Knowing how to restore and maintain blades and edges will take on new importance, as sharp tools will be necessary for survival, and sharpening will be a marketable and barterable skill.

Besides knives and scissors, we will regularly rely on axes, machetes, fingernail clippers, chisels, gouges, wood planes, drill bits, saw blades, animal hide preparatory tools, and shaving razors, just to name a few.  Different edges require different sharpeners and techniques to achieve sharpness, but with a little bit of investment in some simple tools and also time for honing your skills (pun intended), the dividends will pay off for years to come.  Unlike some niche survival skills and tactics, sharpening is extremely useful in every-day non-emergency situations, as you will finally be able to maintain blades that actually slice through tomatoes without clumsily squishing out an eight-inch radius of juice blast!

Some blades and tasks are more sensitive to dullness than others.  For example, a dull chef’s knife will get the job done, however it will take longer, leave jagged edges, and require more force.  These last points are issues of safety, for the greater the force leveraged on a knife, the less control the user typically has.  Also, dull knives have a greater propensity for slipping or bouncing off of surfaces before cutting in, which increases the likelihood of lacerating oneself.  Wounds inflicted by dull knives also tend to be more ragged, potentially necessitating medical attention—the last thing you need in a survival situation.  Other cutting tools, such as straight razors and plane irons are rendered virtually unusable when dull.   Dull machetes and axes are also inefficient and dangerous.

All sharpening methods rely on the same basic principle—abrasive particles that are harder than the blade are used to create a series of scratches on the cutting edge.  Coarse abrasive particles cut quickly and remove relatively large amounts of metal from the edge.  Fine abrasive particles cut more slowly, yet leave a finer scratch pattern.  The finer and more uniform the scratch pattern, the sharper the edge will be.  Eventually, the progression to finer and finer abrasives yields a mirror finish and an exquisitely sharp edge. 

Sharpening typically occurs over a number of abrasive, or “grit” stages.  A coarse or low grit stone first removes deep gouges and scratches.  Fine, or high grit, media are used after coarser abrasives have created a uniform edge.  This can be compared to a wood working analogy, in that a progression of finer tools is used to craft a piece of work.  An axe is used to cut lumber to a coarse shape, saws work coarse lumber to the close-to-finished shape of the desired piece, and then sand paper and scrapers are used during the last finishing stage.  Sandpaper is not used to cut down the tree!  In theory it could be, but you would waste a lot of paper, and it would take more time and effort than you probably wish to spend.  Conversely, you would not use an axe for the final smoothing.   For the same reasons, you would not use a fine abrasive for the initial sharpening of an edge.  The idea is to take rough (coarse) cuts of metal off the edge to get the shape of the blade right and to eliminate deep gouges.  Once all the scratches made by the coarse abrasive are uniform, it is time to progress to a medium abrasive.  Once the medium abrasive has created a uniform series of scratches, it is time to move to a finer abrasive.  One of the biggest hurdles to creating a good edge is impatience.  By switching to the next finer abrasive too soon, coarse scratches persist and a sharp edge will remain elusive.  Each progression of finer scratch pattern must completely remove the coarser scratch pattern from the abrasive that came before.  Going back to the lumber example, even if you used the axe to chop through 95% of the log, switching to sandpaper at this point would still be foolish.  Likewise, even if you remove 95% of the coarse scratches with a medium grit abrasive, moving a fine abrasive will not readily remove the remaining 5% of coarse scratches.

The tools needed to begin sharpening are relatively simple, but the vast array of choices can be dizzying for those new to sharpening.  On one end of the spectrum resides sandpaper that is simply adhered to a flat surface, while the other end of the spectrum hosts multi-thousand-dollar sharpening machines.   This article focuses on the middle ground, which is the domain belonging to sharpening stones.  Sophisticated sharpening machines will be largely ignored, for when the power goes down, so do these machines.  Additionally, replacement parts may be impossible to source.  A brief description of the utility of sandpaper is worth mentioning, however. 

Sand paper is inexpensive and only requires a flat surface such as a mirror, glass pane, or a block of granite as the underlying substrate.  Even MDF (medium density fiberboard) or cast iron tool tops (such as table saw tops) can be used with some success.  Utilizing a series of differing sandpaper grits can be an extremely effective means of sharpening edges.  Vast amounts of information regarding sandpaper-based methods are available on the internet, and they can typically be found by typing the phrase “scary sharp” in a search engine.   In a nutshell, sandpaper is generally adhered to a flat surface with a spray adhesive.  The edge to be sharpened is placed on the sandpaper, and worked to create a uniform scratch pattern.    A low grit (50, 80, 100) paper is used to shape the edge, followed by a progression of finer grits (150, 180, 220, 320, 400, 600, 1000, 1200, 2000, 5000 or even finer).    Stopping at between 600 and 1200 is suitable for everyday use, but finer edges (that are more delicate and more easily dulled and damaged) require higher grits.   To set this system up, it takes very little initial monetary output, as sandpaper and float glass is inexpensive.  The problem is that sandpaper may not be readily available in a long-term survival situation, and high quality wet-dry silicon carbide paper in fine grits is rather expensive and may not be readily available at box stores.  Overall, this methodology is useful to have in one’s bag of tricks, but may not be as practical or cost effective (in the long run) as having some quality sharpening stones.


It should be noted that I have no financial interest in any brands of the sharpening stones mentioned below, and have included reference to brands I have either personally used or that have a reputation for quality.  Like all tools, I would recommend buying the best you can afford, staying far away from cheap imports.

Sharpening stones come in a few basic varieties: Oil stones, water stones, and diamond stones.  Oil stones are the stones that our grandfathers used, and require a coat of oil to work effectively, hence the name.  They were traditionally natural stones (e.g. “Arkansas stones”), but man-made oil stones are readily available today from manufacturers such as Norton.  Natural Arkansas stones vary in coarseness, and are typically available in finer forms than their man-made counterparts.  The types of Arkansas stones are, from coarse to fine; “Washita,” “Soft Arkansas,” “Hard Arkansas,” “Hard Black Arkansas,” and “Hard Translucent Arkansas.”   Oil stones typically cut more slowly than water stones, and are more difficult to clean due to the use of oil.  They are, however, the most economical of the stones available.  Quality oil stones can be had, at the time of this writing, for under $20 each.

Water stones need no oil, but require water as a lubricant, as their names suggest.  They are also available in natural varieties, but are rare and cost prohibitive, so only man-made water stones will be considered.  They cut faster than oil stones since the binders that hold these stones together are relatively soft, which allows worn abrasive particles to slough off the stone during sharpening to reveal fresh and sharp underlying particles.  Of course there is a tradeoff, which is that water stones “dish out” more quickly due to their softer construction, so they must be flattened regularly (with a dedicated flattening plate).   Water stones are also available in much finer grits than oil stones (up to 30,000 grit).  Water stones vary in price, with finer grits costing substantially more.   Norton makes combination stones with differing grits on each side of the stone, and for around $150 dollars, two stones (4 grits: 220/100, 4000/8000) and a flattening stone can be had.  I personally feel this is an excellent approach for a basic “do it all” sharpening setup.  Water stones are easy to use and clean, while not being terribly expensive.  Extremely fine grits, however, can be upward of $300 per stone.  The Naniwa Chosera line of Japanese water stones, though I have not personally used them, are extremely well-regarded, and warrant consideration. I regularly use Shapton glass stones (1000, 4000, 8000) and a DMT Coarse Diasharp stone to keep my glass stones flat, and highly recommend this setup.  The Shapton stones cut fast, don’t dish out quickly, and are super easy to use.  They are, however, fragile as they are manufactured on a glass backing, and relatively expensive (around $300 for such a set).  In a critical situation where “two is one, and one is none,” glass stones may not be my first choice without a backup in place. 

Diamond stones are not stones at all, but rather metal plates impregnated with diamond particles.  They cut extremely fast and their surfaces remain very flat over time.  They use water instead of oil, so are also easy to clean.  Diamond stones are typically more expensive than water stones in average grits, but less expensive than ultra-fine water stones.   Diamond plates are also not readily available in the extremely fine grits found in water stones.  For a long-term survival scenario, these stones are arguably the best choice if you could only have one set of stones, as they are robust and remain flat.  A set of four diamond stones by DMT (x-coarse, coarse, medium, fine) sells for around $200, and represents good value for overall utility.  When choosing diamond stones, look for brands offering monocrystalline construction, as these stones tend to cut faster and last longer than polycrystalline varieties.

Strops should not be left out of the discussion.  A strop is simply a piece of leather (or canvas) used to polish an edge.  Unlike stones, strops do not remove material from a blade, but rather straighten or align the edge.  A strop is essential for achieving a keen edge on a straight razor, and is also used for creating a superior edge on woodworking tools such as chisels or plane irons.   Strops may be impregnated with fine abrasive particles, such as “Jeweler’s Rouge,” or chromium (III) oxide to aid in achieving an even better finish.  For kitchen and utility knives, a honing steel, or simply “steel” is often used for a similar purpose (A “steel” may be made of steel or ceramic).  Learning to use a steel is a requisite for maintaining sharp kitchen knives, as it allows prolonged use of knives between sharpening sessions, since one can periodically “touch up” the edge with just a steel.

What about electric kitchen knife sharpeners?  They are super-fast, easy to use, and require virtually no skill.  As long as you have electricity they will work relatively well.  However, one can’t always count on having electricity.  Also, if a part breaks or wears out, the apparatus will be rendered useless.  Lastly, they can only sharpen thin-bladed knives, but a set of stones can be used to sharpen axes, combat knives, scissors, lawnmower blades, pruners, and dozens of woodworking tools, just to name a few.   High end sharpening stations are more versatile than the kitchen knife sharpeners, but again have dozens of moving parts and rely on electricity.

A number of specialty stones are also offered in the market, and are intended for specific tasks.  For example, round and triangular stones can be used for sharpening serrated blades and gut-hook skinning knives, and even some nail clippers.  Gouge sharpening stones are shaped to accommodate a wide variety of wood working gouges and carving tools.  Smaller stones can be used for sharpening fish hooks, saw blades, small scissors, tweezers, and even carbide router bits and carbide tipped saw blades.  It should be noted that a diamond stone is needed to sharpen carbide.

The last tool worth mentioning is the file.  Files are useful, especially in conjunction with stones, for sharpening axes, hatchets, lawnmower blades, gardening equipment, shovels, and saw blades.  Files could be the subject of their own article, but for the sake of brevity only a brief introduction follows.  Files are also indispensable for general metalworking.  Mill files come in a variety of “cuts” (the pattern of ridges on the tool) and roughness.  Files generally follow the nomenclature of, from roughest to smoothest: “rough”, “middle”, “bastard”, “second cut”, “smooth”, and “dead smooth.”  To make matters more confusing, a 10” long second cut file is typically coarser than a 6” long second cut file, and levels of roughness vary from one manufacturer to another.   Files can be flat, half-round, round, and tapered.  For basic sharpening of garden tools, lawnmower blades, shovels, and axes, an initial shaping with a file is the most practical way to form an edge when exceedingly dull or damaged.  They cut more aggressively than the coarsest of stones, and do so far faster.  No sharpening set would be complete without at least one flat mill file, but a selection of flat, round, and tapered files, in both coarse and fine cuts is ideal.  Small tapered files are used to sharpen hand saw blades, while a small round file is required to properly sharpen a chainsaw blade.

There are also numerous jigs and fixtures on the market to aid the would-be sharpener in his or her quest for that perfect edge.  I would avoid these items in general, and instead focus on the skill of sharpening.  Jigs can break, but once you have acquired the knowledge and sharpened your skills (another pun!) that can never be taken away from you.  Knowledge is power.


Since there are so many options for sharpening implements, it is admittedly confusing at first.  However, in choosing the right tools, some first questions to ask are:1) What are you sharpening?, and 2) Where are you sharpening?  The “what” is simple—buy what you need to sharpen the tools you will need.  The “where” simply refers to whether you are in a stable location or preparing for a bug-out.  Therefore I have put together four hypothetical kit examples: two bug out kits-ultralight and standard, a basic sharpening set for home use, and a comprehensive sharpening set for home use.  Below each set is a description of what task can reasonably be accomplished with the tools at hand.  These are not written in stone, so feel free to adjust based upon your needs.

Bug Out Kit-ultralight
Diamond credit card sharpeners – Coarse, Fine, Extra Fine

This kit is lightweight (under 7 oz.), inexpensive, and suffices for most common tasks.  Each stone is a metallic credit card-sized diamond plate.  They are a bit heavy for my EDC (every day carry) preferences, but not totally impractical.  For a bugout bag, these are a no-brainer.   This set gives you the ability to sharpen chef’s knives, smooth pocket knives, smooth combat knives, machetes, axes, hatchets, adzes, swords, scissors & shears, arrow heads, fish hooks, as well as craft and woodworking tools.  Tools, such as axes or lawnmower blades with major nicks would still likely need the use of a mill file.  Blades will not achieve a keen edge like what is possible from fine grit water stones, but can be made very sharp and very functional. 

Bug Out Kit-standard
Extra Coarse/Coarse diamond folding sharpener
Fine/Extra Fine diamond folding sharpener
Fine diamond folding Serrated Knife Sharpener

This example contains three collapsible sharpeners that unfold like balisongs (butterfly knifes) to reveal a sharpening stone.  Two double-sided sharpeners yield four stone grits, and a fine pointed stone sharpener is used for serrated surfaces.  Again, blades will not achieve as keen an edge like from higher grit water stones, but will be sharp and totally functional.  Another, more compact, option would be to use the credit card sharpeners from the ultralight bug-out kit, coupled with the fine diamond serrated knife sharpener.

Basic Sharpening Set-home use
Diamond Stone Set: X-Coarse, Coarse, Medium, Fine, X-Fine
Chef’s Steel
Flat Mill Files: Coarse and Smooth

This very basic set allows one to sharpen: chef’s knives, pocket knives, combat knives, machetes, axes, hatchets, adzes, swords, scissors & shears, fish hooks, chisels, plane irons, garden equipment, and lawnmower blades, at a minimum.  Since the set is diamond, carbide inserts on router bits and the like are also sharpenable.  The stones are far larger than their folding counterparts, so will last longer (since the surface is greater and wear is more widely distributed) and are easier to use, as they are placed on a table top so both hands can be used for sharpening.  Pocket sharpeners require one hand to hold the sharpener and one hand to hold the tool to be sharpened, which is not optimal for maintaining a consistent angle while sharpening, so stellar results are more difficult to achieve.  Again, augmenting this kit with a folding serrated knife sharpener adds the ability to sharpen serrated edges.

Comprehensive Sharpening Set-home use
Water Stone Set:  220, 500, 1000, 4000, 8000
Flattening Stone for water stones
Backup Diamond Stone Set: Coarse, Medium, Fine, X-Fine
Chef’s Steel
Sharpening Rod – round (ceramic or diamond)
Sharpening Rod- Triangle (ceramic or diamond)
Leather Strops- plain and compound impregnated
Files: Mill file selection, round file selection, tapered file selection.  Large and small, coarse and fine for each.

Having water stones will allow a keener edge than what is possible in the sets above due to the 4000 and 8000 grits, as well as the strops.  It is these additional tools that allow for the sharpening of straight razors, and also to achieve razor sharp edges on most tools.  The sharpening rods open up the possibility of maintaining serrated knives, gut hooks and seat belt cutter hooks.  The diamond stones provide a robust backup for the more fragile water stones, and also allow one to sharpen carbide tipped router bits and saw blades, while the expanded selection of files is used for hand saws and chain saws blades.   Additionally, some general metalworking and gunsmithing tasks are possible with the above stones and files.

But wait!  How exactly do I sharpen X,Y, or Z?  You never told me!!  Smooth knives are sharpened differently than serrated knives, and axes are sharpened differently than chisels.  The focus of this article is not to teach you the techniques needed to sharpen particular types of edges, but rather to convey the importance of possessing sharpening skills in emergency situations and to explain what tools are needed to accomplish the tasks at hand.  It is also vital to understand that learning to sharpen effectively and with efficiency takes practice, and is a perishable skill.  I therefore recommend, at the very least, that one regularly sharpen kitchen knives and pocket knives to achieve and maintain a reasonable skill level.   Your first attempt at sharpening a kitchen knife may yield a blade that is duller than when you started!  This changes with practice.  Another article, far longer than this one, could be written that breaks down the procedures necessary to sharpen all the tools mentioned above, but in this case a picture is really worth a 1,000 words.  I would therefore recommend a book such as The Complete Guide to Sharpening by Leonard Lee, as this text covers the vast majority of sharpening situations one can expect to encounter, is full of photographs, and is a worthy reference for any preparedness library.  Additionally, there are hundreds of YouTube videos that show the procedures and motions used to achieve edge nirvana, but I would caution that some are worth far more than others. 

When faced with TEOTWAWKI, chopping wood, preparing game, cooking, bushwhacking, hunting, self-defense, personal hygiene, and tool maintenance for woodworking, leatherworking, and virtually every other craft will heavily rely on edged tools.  With a little bit of investment and regular practice, you can ensure that your survival tools remain safe and functional while also creating a skill set that has bartering value—both of which may help you through hard times and promote your survival.