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Phillosoph

Fruit Juice and Knives

A friend of mine has warned me she intends to bring me a knife for some attention. It needs sharpening, but also has some marks. Too much touching the blade and not enough (if any!) oiling.

Gentle Rust Removal

If you paid attention in Science class you will know that you can remove rust with acids such as vinegar. Often this leaves a discolouration, however.
An interesting technique I have used is to remove rust with pineapple juice. Pineapple juice is a very mild acid. If you soak a blade for a few days it gently removes rust patches, leaving much less discolouration. Something like a vase is ideal. Just submerge the blade in juice to the depth required. If you lack a vase then the juice carton itself may be a suitable shape. You may have to brace it so the weight of the knife does not cause it to topple over.
I have only ever used pineapple juice for this, but other fruit juices should work. I suspect grapefruit juice may be too strong, but that is just a guess and I may be wrong.

Fruit and Bread Knives

I was watching a movie recently and a character makes a comment about the wisdom of cutting tomatoes with a bread knife. I guessed this may have been due to most people not having genuinely sharp kitchen knives, but I ran the idea past a chef friend.
My chef friend agreed one should cut tomatoes with a bread knife, and that it should also be used for other acidic fruits such as lemons and limes.
His explanation was that the acid of the fruits prematurely blunted other types of kitchen knife. The serrated edge of a bread knife was less affected by this. He did note that many chefs he had worked with were unaware of this.
So, if you are cutting acidic fruits in your kitchen, reach for a bread knife or serrated blade, preferably one of stainless steel.

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Phillosoph

Pull-Sharpening

My recent project with the machete has spurred me to sharpen a few of the tools I have around.
In my book, “Survival Weapons”, I devote an entire chapter to the topic of sharpening. That chapter remains a useful guide to a topic that can sometimes seem cryptic.
At this point I should explain that one of my “virtues” is that I am lazy. According to admiring colleagues, I can be usually be expected to find the simplest, most stress-free method of getting a job done. Over the last week or so have I noticed that how I sharpen some tools now varies somewhat from the techniques described in the book.
Regular readers will know I own a number of kukris, as well as other large blades. There was this period of ill-health where I spent my holiday budget on swords instead! Probably safe to say I have more large blades than the average prepper. Some of these have concave or convex edges, or in the case of kukris, both. Some of the techniques for sharpening you will see on some websites are not ideal for such tools.
I have, over the decades, acquired a large number of sharpening systems. The one I have found myself using the most recently is shown above.
I inherited this stone from a deceased colleague. It is most likely an Arkansas stone. The stone itself is about three inches long and a little under an inch wide. It is firmly mounted (glued?) to a wood tray about four and a half inches long by an inch and a half wide. This provides a very nice handle when using the stone. Beneath the base is the matching wooden lid. The stone has just been cleaned. I used a little washing-up liquid and some water to remove most of the grime. A little bathroom cream cleaner took of the remaining residue.

The Angle-er

The device below I call an “angle-er”. Having this nearby helps you visualize the correct angle while sharpening. This particular example has angles of 22.5, 15 and 30 degrees, which are pretty good choices for general usage. Some may prefer 17 or 20 degree and 35 degree angles. Once you have your tool close to the correct angle it is easy to vary it a couple of degrees if desired.
The beauty of this Arkansas stone is that I can move it instead of the blade. Unlike a larger flat stone this one is narrow enough that it can follow a curved edge, rather than attempting to grind it straight.
The method I use is essentially the same as was described for sharpening a machete, only instead of using a file I use a suitably sized stone.

Sharpening Styles

There are a number of ways that a stone or file can engage a blade. In the movies you often see a stone being dragged down a sword edge. Looks good but I have my doubts as to how useful this would be in the real world. Usually we want the sharpener to pass down the edge with some movement across the edge too.
The sharpening technique most often seen in “how to” guides is what may be called “push-sharpening”. If you were using a large, flat stone, you would move the blade as though you were attempting to shave the surface of the blade.
You will also see “push and pull” sharpening where the blade moves back and forth across the stone. I personally don’t use this method much and would not recommend it for the novice. Keeping the angle constant over the different strokes requires skill and it is easy to over-do things. If you can maintain an angle it is useful for quickly establishing a secondary edge.

Pull Sharpening

These days I tend to use pull-sharpening techniques. As you might expect, the blade moves in the opposite direction to push-sharpening. One of the advantages of pull-sharpening is that it is easier to move the sharpener across the blade edge, rather than moving the blade. This is useful when working on large or awkward blades but can be applied to small blades too. One does not need a workbench or similar for pull-sharpening. I usually sit on the sofa, watching the telly and using the advert breaks constructively.
Pull-sharpening is a good technique to use with small triangular-section sharpening stones. It is also suited to the oval stones sold for sharpening tools such as scythes.
When you use a leather strop you are using an action like pull-sharpening. If you did not you would cut the leather! If you are sharpening a tool using a high-speed device you should be using a pull-sharpening technique. This is so that if the high-speed wheel or belt snags the blade it will throw it away from you rather than at you!
One reason I like pull-sharpening is it is easier to view the angle of contact that sharpener and blade make. It is also easier to give both sides of the blade similar treatment without trying to use your non-dominant hand or run around the table.

Lubrication

Generally, I do not use lubricants such as oil, water or spit, for sharpening. An article I read, written by a professional sharpener, claimed that his experiments had concluded dry sharpening produced superior results. Much to my surprise, this article can still be found on-line! Generally I only apply water if a stone or sharpening system is particularly crumbly or high friction.

Pull Sharpening Technique

For example, hold your blade with the edge to the left. Place your sharpener at the desired angle, and push your sharpener right to left, moving it away from the blade spine or centre. A “pass” starts at the heel of the blade and moves towards the tip. A pass may take several strokes, depending on blade length and sharpener size. Make three to five passes on a side, then change. For the other side, you have two choices. You can flip your blade over so the edge is to the right and stroke the edge left to right; or you can turn the blade upside down and stroke the other edge right to left. Use whichever technique you prefer and better suits the tool being sharpened. Keep changing every three to five passes, reducing the number of passes as your tool approaches the desired sharpness.
Pull sharpening is a good technique if you are not that confident about your sharpening skills. It is easy to check and maintain the desired angle. It is also not a particularly aggressive technique, so you are unlikely to damage your edge. In fact, I recommend you try a very light touch as you make you strokes and passes. Let your stone trace the curves of the blade rather than trying to remove them. You will find that as the edge geometry takes shape, you will be able to feel when the stone or file is at the correct angle. Light pressure also lets your feel where sections of the edge have irregularities and need more work.
So far, the only problem I have had with pull-sharpening was with a particular multi-tool where the blade was unlocked and rather loose in the open position. Pull-sharpening tended to pull the blade closed. This would only have been a danger if I had wrapped my fingers around the grip while sharpening, rather than holding the back of the blade.
Pull-sharpening is a useful technique to add to your repertoire. The knives in my kitchen are kept sharp mainly by a butcher’s steel and a set of crock-sticks I have in a cupboard there. I maintain my assertion that crock-sticks (ceramic rods) are a very good way to teach yourself the fundamentals of sharpening. Crock-sticks are a form of push-sharpening, but pull-sharpening has improved my technique in using these too. Rather than just slicing down, I now use a lighter touch and let the stick surface trace alone the curve of the edge, keeping contact to the very tip and engaging the edge at a better angle throughout its length.
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Phillosoph

Breakfalls: The Lateral Roll

Close combat has been described as the art of knocking someone down and kicking them while they are down. In this light, it is perhaps surprising that breakfalls are a rather neglected skill in many martial arts and self-defence courses.
The book Arwrology recounts and incident where a serviceman uses a breakfall to avoid injury when he is thrown to the ground during a bombing raid. Breakfall techniques can be incorporated into the warm-up for a training session in any martial style. In an ideal society, children would be taught breakfalls in kindergarten, learning a useful skill to save them from possible injuries in later life.
It will come as no surprise that Crash Combat and Attack, Avoid, Survive both contain sections on breakfalls. Breakfalls can be classed as “rolls”, “slaps” and “non-traditional”. A roll is self-explanatory. Slaps use the impact of the forearms and palms on the ground to brake the fall. In my books, the non-traditional techniques are represented by the cartwheel and the parachute landing fall. Once, on an isolated mountain path I missed my footing. Executing a parachute landing fall saved me from injury in a remote location, even though I was wearing a heavy pack.
In my books I also describe the forward roll, and slap techniques to the front, side and rear. Today I will look at two additional techniques.

The Rear Roll

The first is the rear roll. This resembles the rear slapping technique, but without using the forearms to brake you. The starting posture for learning resembles that used to learn the rear slapping roll. Instead of using your arms you continue to roll backwards, across your back and shoulders. It may be necessary to roll several times. Ideally you finish on your feet, ready to stand up from the squat position.

The Lateral Roll

The second technique is the “lateral roll” (yokonagare). The starting position for learning this resembles that used for the sideways slap breakfall. These photo sequences from books by Stephen Hayes illustrate the principle better than my text does:
The extended leg provides balance, and should be extended straight so that the bottom of the thigh absorbs the impact with the ground. The supporting leg is allowed to fold as much as practical to reduce drop distance. In the first sequence the roll seems to be to the rear quarter rather than to the side. The same starting position and core technique can be used to make a roll to the rear.
The lateral roll has a number of other applications. As well as being a breakfall, the technique can be used to drop below and away from an attack. It can also be used to drop and roll behind cover if spotted or fired upon. Possibly the move could be incorporated into certain sacrifice throws.
This is a move that can be initiated from any stance where the weight can be easily transferred to the rear leg. My Capoeira background notes that the actual roll action is preceded by a posture similar to negativa. It also resembles the semi-squat position often seen with some Chinese martial arts. For negativa and other breakfalls, see my books.

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Phillosoph

Battle of Jangsari: Camouflage

Recently I watched the movie “Battle of Jangsari”, set in the Korean War. I enjoyed it, and many of my readers may do so too. So as not to spoil your enjoyment, I will try to avoid any possible spoilers that I can in the following passages.
The photo below shows the North Korean troops that are sent as reinforcements. Notable on their first appearance is the bundles of grass/ straw/ rushes that each infantryman has sprouting from his back.
At first glance I thought this might be an earlier example of the device described as in a previous post as the Vietnamese Camo Ring. Subsequent scenes show the foliage attached directly to their shirt/ blouses. The intention is the same, however. If an enemy aircraft had appeared these infantrymen would disappear.
“Osprey Men-at-Arms 174: The Korean War 1950-53” includes the following passage (p.37) on the North Korean summer field uniform:
“The uniform had reinforcing patches on the elbows, trouser seat and knees, and frequently single or double rows of horizontal ‘zigzag’ stitching around the cap and across the shoulders, chest and upper sleeves, which were used to hold leaf camouflage. ”
For some of the movie the South Korean (ROK) soldiers wear captured North Korean uniforms. They do not use camouflage materials, but the means by which they can be attached are clearly seen in some shots. In these examples the “stitching” appears to be relatively substantial cord.
A side view of foliage attached to a machine-gunner’s back. Some North Korean troops also have foliage attached to their upper arms, although the means of doing this is not clear in the film. Presumably loops might also be sew to the sleeves. Many of the North Korean soldiers are also wearing short capes of what appears to be camouflage net. In the movie this was not clear and appeared as an irregular shape of mossy green-grey on the upper chest. In the stills this is much more clearly seen to be net.
The Russian-style shoulder-boards worn with the North Korean uniforms appear fairly impractical. Men-at-Arms 174 notes that these shoulder-boards tended to fade less than the rest of the uniform, making them stand out as regular shapes and thus detrimental to camouflage.
Also note that none of the actors have camouflaged their helmets, leaving a distinctive, recognizable shape. As I have pointed out in recent posts, shape disruption and texture contribute far more to camouflage than colour. Notable in this movie is that the North Korean uniforms work far better in the terrain shown than the green American fatigues worn by some characters. The Osprey publication states that the North Korean summer field uniforms was “olive khaki shade faded rapidly to a light yellowish hue”. Actual appearance varies in the photos since the soldiers of both sides get realistically dirty.
Minor spoiler follows: In one scene the first sergeant stamps on a mine several times and chides the student soldiers, telling them it is an anti-tank mine and ten of them could run across it without setting it off. This is not strictly true. The mine shown is an American M15 that is claimed to need a force 159 to 340 kg (350 to 750 lb) on pressure plate to set it off. “Taming the Landmine” (p.51) by Peter Stiff describes how repeated passages over an anti-tank mine would “settle” the trigger mechanism of some models until they became sensitive enough to be set off by a pedestrian, donkey cart or bicycle tire.

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Phillosoph

Cleaning Up Blood.

My first post on the relocated blog, and in truth, I wish it left me under happier circumstances. Both the girlfriend and myself are experiencing considerable health problems, compounded with some insidious behavior from several sources. I will spare you the details, but will note that one of the “lighter” incidences in the last week was a cat giving birth, then rejecting and trying to kill its kittens! Luckily one of the other cats stepped up and the kittens are now safe and doing well.
The other cat had decided it wanted to give birth while wandering around the house, often trailing a kitten still attached by its umbilical cord. Blood and other secretions were left around the house, which was not conducive to finding new tenants for vacant rooms.
This situation reminded me of a piece of knowledge that is not as widely known as it deserves. In the past I have been called upon to clean clotted blood from scientific equipment. Often these clots were within very narrow tubing. Anything that would fit down the tubing had insufficient strength to break up the dried blood.
The movie “Carrie” was on last night, so the fates seem to be telling me it was time I passed this knowledge on.
The solution (literally!) is 0.9% (isotonic) saline. Nine grams of common table salt/ sodium chloride dissolved in a litre of tap water. Or 0.9g in 100mls, 4.5g in 500mls or any variation of such.
One advantage of using isotonic saline is that it will dissolve clotted blood without causing further lysis of the blood cells, and releasing the pigment.
A friend of mine once got blood on his jeans and asked on facebook how he should remove it. Luckily for him I responded first and told him about isotonic saline. There then followed numerous other suggestions, many of them exotic or expensive, several of which that would have marked or destroyed his jeans. This was a nice example of what is so often bad about social media. My friend used saline, and his jeans survived.