How to Build an Oven

In the P.A.W., it would be nice to be able to make a nice loaf of bread or even just cook something without using a campfire and risking burning your food all the time.  This isn’t as far-fetched of an idea as you may think.  In fact, you could build an oven to use while you’re travelling if you have the time.

The basic premise of cooking in a conventional oven is cooking by convection.  When you bake a loaf of bread in a modern conventional oven, the heating elements in the oven heat the air closest to the flames, causing it to rise, moving the colder air near the flames and repeating the process until the air inside the oven is a relatively uniform temperature.  You then place the bread dough in the heated air of the oven.  The heated air transfers its heat into the dough, causing the temperature of the dough to rise to roughly the same temperature as the air around it.  At this temperature, the ingredients in the dough cook and eventually you have bread.

Earth Oven

The easiest and quickest oven you can build is an earth oven.  You don’t need anything too special or permanent to build it – just some mud and a fire.  The basic concept of an earth oven is that you are creating an enclosed space that holds the heated air required to oven cook anything.

Because dirt/mud is exceptional at holding, we’ll use mud to build the shell of our oven.  We use mud because it is malleable until it drys, at which time it will hold its shape.  The first thing we need to do though, is find a way to make our oven space hollow.  The easiest way to do this is to use wet sand.  We can shape the wet sand into whatever form we want and the mud won’t destroy that shape, and dry sand is just as easy to remove from our oven as wet sand would be.  So we first make a mold for our hollow space, then we coat the mold with several inches of mud.  The thicker the mud walls, the more heat it will retain for longer.  Let the mud dry into a hardened mound, then cut an opening into one side of the mound all the way to the sand/molding material.  Dig out all of the sand/molding material and you now have an oven!  Build a fire inside the oven to heat the walls of the oven.  Once your oven is to temperature and the outside of the oven is hot to the touch, put out your fire and remove all of the fire material from the inside of the oven.  Place your food inside the oven and cover the hole up to avoid letting any heat escape.  Eventually, your food will be cooked.

Pompeii Oven

The Pompeii oven is a precursor to the modern brick oven, commonly used in pizzerias.  The Pompeii oven works on the same principles as an earth oven, and is actually the evolutionary successor to the earth oven, but it is more permanent and used with the fire still inside the oven while cooking.

For convenience, a Pompeii oven is built at around waist height or higher (because who really wants to crouch all the time while they are cooking?).  This is best acheived by building a dais out of brick or stone or some other material that is fire proof and resistant to age and the elements.

Then you want to build a slab that the oven will be built onto.  You might be fancy/lucky enough to have concrete and rebar to make this slab from, otherwise go for a material that is fire proof and resistant to age and the elements.

When considering bricks or brick material for building your oven, there are two factors to consider:

  1. Can the material withstand high temperatures? (refraction)
  2. How well can it reflect heat? (conductivity)

Ideally, you want a high refraction, low conductivity material because it won’t be destroyed by the heat of the oven and it will reflect heat given off by the fire efficiently.  Firebricks (bricks made of a type of clay composed of high levels of alumina and silica) are the ideal material, but ceramic and clay will work just as well.

Lay out a pattern of bricks on your slab for the floor of your oven.  Most people use an offset pattern for the floor because it prevents a seam in the floor which can cause your food to snag when putting it in or taking it out of your oven.  Ultimately, it doesn’t matter how you lay them out as long as they are tightly lined up with each other to prevent heat leakage.

To form the dome of the oven, you can either build it free standing, or over a wet sand mold as with the earth oven.  Building the dome free standing, you will lay the bricks one layer at a time and let the mortar dry before moving on, occassionally adding a wedge between rows of bricks to account for curvature.  Don’t forget to leave space for an opening!

If you don’t have access to modern mortar, you can use clay, mud, pitch (tar), or you can make your own.  Essentially, you just need something that will bind to your bricks to make a solid structure.

When building the door and door frame for the oven, you want to ensure that your door is at least slightly bigger than the opening in the oven.  This will ensure that the door doesn’t swing into the oven and, when closed, forms a seal to heat and moisture leakage from inside the oven.  Don’t make it an airtight seal.  An airtight seal will cause what is known as backdraft: The flame will go down as it burns through the existing oxygen, then when you open the door the onslaught of fresh oxygen causes the fire to roar back up, potentially exploding out the opening of the oven and burning you.  The door itself can be made from whatever you can manage: a hunk of scrap metal, dried mud, a rock, an old oven door, etc.

It is also a good idea to build a chimney into the door frame so that smoke and hot air have an escape path that isn’t your face.  _Don’t put a chimney into the oven itself!_  This fundamentally defeats the functionality of the oven.

After your oven is built, you need to purge it of any excess moisture.  This curing process ensures that your oven doesn’t crack when in regular use.  To do this, build a small fire for 6 hours each day for 5 days.  Start at 300F and increase by 50F each day.  If you can’t accurately guage temperature, just build a small fire and increase the size each day for 5 days.

Once you’re ready to actually start cooking with your oven, start you’re fire near the front of the oven and once it gets going, push it off to one side or the back and let the oven heat until the outside is hot to the touch.  Then cook to your hearts content!

How to Weld

In a post-apocalyptic world, scavenging is the order of the day and you’ll likely be able to find plenty of scrap metal lying around (or still attached to something that nobody is using).  That metal could be useful by itself, but it might be more useful if you could weld smaller pieces together to form one large structure.  Plus, knowing how to weld is a skill you can trade on, unlike that Cisco certification you spent thousands of dollars on.

Fundamentally, welding is a simple process – heat two pieces of metal until they’re nearly liquid and force them together meshing one piece to the other.  Most of the time, a filler material (commonly a more maleable, and thus easier to liquify metal than the one being welded) is used to aid in creating a cohesive bond, or joint, in the metal pieces.  Over the years, industrial welding has evolved into a futuristic world of laser welders and using ultra sonic waves to fuse molecules together, but these types of welders are crippling expensive and rare, and thus you are unlikely to have access to them after The Event.  For our purposes, there are three types of welding: forge, torch, and arc.

Forge welding is the most primitive form of welding.  To forge weld, you heat the two pieces of metal until they are red hot, but not liquified. Place them on an anvil with one piece slightly overlapping the other and hammer them back down to the thickness of either piece of metal and thus forcing a mesh of the two pieces.  Don’t expect this technique to work on steel, it will only work on more maleable metals that approach or cross the liquification point in forge temperatures (think bronze, copper, iron, etc).

The next step up is torch welding.  To torch weld, you will need a torch – the most common torch used in welding is an acetylene torch, which is essentially a nozzle that mixes pure acetylene with pure oxygen, which you light as it comes out the end.  An acetylene/oxygen flame burns at over 3000 degrees celsius which is the hottest flame you will get from readily available combustible gases.  If you are making a makeshift torch, you can use any pure combustible gas and you can use compressed are instead of oxygen for your oxidizer, but you won’t achieve the same temperatures as your would with an acetylene/oxygen mix.  Also, you need to make sure you are using some sort of non-return valve in order to ensure that you and your fuel cylinder don’t go up in flames while welding.

To perform a torch weld, place the two pieces of metal firmly together, turn on your acetylene just enough so that you hear gas escaping.  Light the torch and adjust the acetylene until the flame is barely coming out of the nozzle.  Turn on the oxidizer slowly until the flame turns blue.  Point the flame at the joint and move the torch in a circular motion until the metal begins to melt.  If you are using a filler rod, you can insert it slowly into the pool of molten metal to add more to the pool.  Once you have a large enough pool, begin moving the torch slowly down the seam.  If you go too fast, you will run out of molten metal.  If you go too slow you will have too much.  If you are using a filler rod, you will want to keep it in the hot zone of the torch (not close enough to melt it but not far enough that it cools off) to prevent a weaker “cold” weld.  Turn the torch off in the reverse order you turned it on.

The final type of welding you should be familiar with is arc welding.  Arc welding uses electricity to heat metal instead of flame and in this case, you NEED a filler rod.  An arc welder is essentially a placeholder for your filler rod that is attached to a power source.  As electricity passes in an arc from the end of the filler rod to the seam in the metal, it generates a great deal of heat, melting the rod and the metal equally.  There are hundreds, if not thousands, of different types of filler rods available.  Each one has a special purpose it was designed for, and sometimes you’ll need a certain type of rod to do any kind of welding on a certain kind of metal.  We won’t get into that here, just be aware that this is a consideration if you have access to an arc welder post apocalypse.

To perform an arc weld, the first thing you need to do is attach a grounding clamp from your power source to your metal.  This is important because if you don’t do this, the all-important arc will not be generated in order to heat the metal.  To initiate the weld, or “strike the arc,” tap the end of the filler rod against the metal and then hold it at approximately 1/8 inch above the metal.  You will see copious sparks shoot up from the metal – this means you got an arc.  Angle the welder into the direction of movement at approximately 45 degrees and equidistant from each piece of metal (this is important if you aren’t welding two flat pieces of metal together), as if you were dragging the tip of the filler rod along the surface of the metal.  Slowly move the rod across the seam until the joint is complete.

That covers the bare necessities of welding.  These procedures and techniques will get you by in a situation where you need to weld.  There are dozens of advanced techniques on how to weld in different situations, for different types of metal that I haven’t covered here.  Just remember that practice makes perfect, and if you need to weld something intricate “measure twice, weld once.”

Pro Tip: You Can Use Honey to Treat a Wound

When you think of honey, you probably think of that golden fluid drizzling on a warm biscuit.  But did you know that honey can be used as an antiseptic?  There is an enzyme in honey called glucose oxidase that generates a slow release of hydrogen peroxide under very specific conditions.

  1. It must be in contact with oxygen, which is a very necessary part of the reaction.
  2. The acidity of the honey must be neutralized (which it is when it comes into contact with body fluids).

It is also more effective when the honey is diluted in the fluids in the wound.  Because the hydrogen peroxide is released slowly, honey becomes a very effective antiseptic.

In the P.A.W., honey may not be a readily available resource.  In fact, it could be very scarce.  A prepared mind, might learn how to keep bees so that they can have honey available for food and for first aid in that scenario.


How to Make a Rope Bridge

There are certain skills that won’t benefit you right away in the P.A.W.  Knowing how to build a rope bridge is definitely one of them.  If you’re on your own and still wandering around looking for a safe location, this skill will be of almost no use to you.  However, if you’re traveling in a group with more gear than everyone can carry on their backs or you’ve made a permanent settlement and you cross that particular stream/chasm frequently, knowing how to build a rope bridge and cross it is an invaluable skill.

There are more types of rope bridges than you can shake a stick at, so I’m going to go over some of the most basic varieties: the one-rope, two-rope, three-rope, and simple suspension bridges.  All of them rely on several fundamental basics.

  1. Anchor all ropes on both sides of the bridge to a solid, permanent anchor point, like a large rock embedded in the ground or an old tree (big trunk).  In the military, they call these “bombproof” anchor points, as in if you were being shelled, your anchor points wouldn’t give way and leave you high and dry.
  2. You need a suitable loading platform on both sides of the bridge.  The loading platform is where you get on or off of the bridge.  With the more permanent bridge types, this is less of a concern because you can always build a suitable platform.  The platform needs to be relatively flat and close enough to the anchor rope that it isn’t difficult for anyone to attach themselves or any equipment to it.
  3. When constructing the bridge, make sure there is some space between your rope and the anchor point.  Once your bridge is complete, the ropes will all be incredibly taut but they’ll still move around a little bit once the bridge is in use.  If you don’t leave a gap, this can cause the rope to rub against the anchor abrasing the rope, weakening it, and risk the rope snapping.
  4. When tightening the ropes, be careful to not overtighten them.  This will put undue stress on the rope at the knots which could cause the rope, knots, or both to fail while using the bridge.
  5. Never let more than two people cross any of the bridges at a time, especially if they are carrying equipment with them.  The more weight placed on the system, the more likely it will fail.

Transport Tightening System

The anchor mechanism on the near side is referred to as the “transport tightening system” because it is tied in such a way that all the slack can be taken out of the rope, thus tightening the whole system.  It is a rope and series of knots tied around the anchor point in such a way as to secure the bridge and tighten the ropes to the desired tautness.

The first knot you will tie is a static knot (like a wireman’s knot or a figure-eight slip knot) around three to six feet from the anchor point.  Clip a carabiner through the knot with the gate facing upward.  Continue wrapping the rope around the anchor.  At this point you need to decide whether you’re going to do a “dry crossing” or a “wet crossing”.  A dry crossing is when everyone but the first person cross over the bridge.  A wet crossing is when the last person is required to dismantle the bridge prior to crossing. 

If you decide to perform a dry crossing, you will need to add a transport knot into the system.  I personally prefer this method because you only have to have one strong swimmer/climber to initially take the far side rope end to the far side.

Transport Knot

Now that you’ve brought the rope around the tree, go back to the part of the rope on the other side of the tree and make a loop with the piece of rope coming from the far side crossing over the piece that goes around the tree.  Now go back to the part that you just looped around the tree.  Make a bight in the rope and pass it through the back of the loop you just made and clasp it into the caribiner on your static knot further down the rope.

Tightening and Anchoring the Rope

If you didn’t tie the transport knot into the system, clasp the rope into the carabiner attached to the static knot.  Now you need to tighten the bridge.  Pull the loose end of the rope coming out of the carabiner until the bridge is the appropriate taughtness.  Tie the rope off on the anchor point.  You can tie the rope off with any number of knots, but the easiest on to use is a round-turn with two half-hitches.

Collapsing the Bridge

For a dry crossing,after everybody but the last two people have crossed, untie your rope anchor knot and tie it to the second-to-last crosser and have him cross.  As long as the slack end is directed toward the far end from the loop in the rope, the tension will be maintained.  If you want to be doubly safe, you can twist the rope at the carabiner to bind all the rope.  Once that person has crossed, pull the loop from the transport knot out of the carabiner and let the transport knot collapse.  At this point, you basically have a rope tied on the far end anchor point, that crosses to the near end, loops around the near anchor point and back across to the far end.  Have several people on the far end pull the rope tight and anchor the rope to the far end anchor point as described above.  After you cross, untie the rope at both end and pull on the end until all of the rope is on your side.

One-Rope (Commando) Bridge

The one-rope, or commando, bridge is the simplest to build and tear down, but the most difficult and physically demanding to cross.  As the name hints, you only use one rope to traverse your obstacle, meaning you’ll be in an awkward position, using pure muscle strength to drag yourself along the length of the bridge.  This is ideal if you’re only crossing with minimal gear and able-bodied individuals, and in a hurry.  Also, this is probably what your going to need initially when building a permanent bridge in order to move things back and forth during construction.

Crossing the Bridge

Crossing a bridge made with one rope can be tricky.

Two-Rope (Postmans) Bridge

The ever fancy Postman’s Bridge adds a whole additional rope to the Commando Bridge… Fancy!  In this configuration, you walk on one rope and hold onto the second rope at chest level or slightly above.

If you have a lot of equipment or people incapable of crossing a Commando Bridge, but you still need your bridge to be temporary and/or hastily constructed and dismantled, then the Postman’s Bridge is your best bet.  It is a reasonable balance of stability and expediency.  When constructing this bridge, you are basically just building 2 Commando Bridges at different heights.

Three-Rope (Monkey) Bridge

 The Monkey Bridge requires a bit more preparation, and because of the required resources and investment of time in this bridge, it is likely that you will use this in a semi-permanent capacity.  One benefit that this bridge has over the previously discussed is that it can be used to span further distances. 

Fortunately, the construction process is not overly complicated.  Lay your hand and foot ropes out and tie stringers onto them so that the strings wrap each rope at approximately three foot intervals. 

Build the shears by laying out two equal-length pieces of wood and tying them 2/3 of the way up.  Spread them apart at the feet and lash them to a cross brace.

Lay the foot rope in the crux of the lasher, tie it to the anchor on one end and then tighten and tie at the other end.  Do the same with the hand ropes, looping them over the tops of the shears first.

How to Pick a Pin Tumbler Lock

DISCLAIMER: The following is highly dangerous or illegal and it is not recommended to be used under any circumstances, except zombies.

In a P.A.W., there is potentially going to be a whole lot of empty buildings with no owners around.  These buildings will be treasure troves of supplies, tools, and shelter, but the more goodies inside a building, the more likely it is to be guarded by locks, barred windows, and thick doors.  The easiest way to gain access to this stuff is just simply break the door or a window or something like that, but that may not always be convenient or the best approach.  To take a scenario from the UK series Survivors, say you come across an inventory depot for a grocery store chain (a warehouse where all the inventory for a number of stores is stored until they need it).  It’s locked up tighter than a drum with serious security (steel doors, deadbolt locks, barbed wire fences, no windows, etc.).  If you happen to find a pickable lock (and you can pick locks) you could get into the building without permanently ruining the security – meaning you can stay there and keep all the supplies inside away from everyone else’s grubby little hands.

How a Pin and Tumbler Lock Works

Cross Section of a Lock

Take a look at any key you have in your pocket.  The shaft of the key is a series of peaks and valleys.  Each of the peaks coincides with a pin inside the lock.

Every lock has a series of pins of varying lengths.  Each pin is divided into two pieces, the top halves all being the same length and the bottom half being the excess length.  If the wrong key (or no key) is inserted into the barrel, the pins prevent the barrel from being turned.  If the appropriate key is placed into the barrel, the pins will line up so that the top portion is perfectly outside the barrel, and the bottom portion is perfectly inside the barrel – allowing the barrel to turn freely inside the lock (and thereby locking or unlocking the door).

Picking Locks with Lockpicking Tools

A Tension Wrench

A lockpicking set (at its most basic) consists of a tension wrench and a pick.  The tension wrench is a strong, thin piece of metal with a 90 degree bend at one end.  As the name implies it needs to be strong enough to withstand a little tension.

The pick can take on any number of shapes.  A masterful locksmith or lockpicker might be able to tell you the benefits of using one pick over another or what benefit different shaped picks have, but for our purposes you only need a simple half-diamond pick.  This is the most versatile pick in any kit and the one pick to have if you only have one.  The half-diamond pick is a straight pick with a triangle-shaped peak at the end of the pick.  The half-diamond pick is used to trigger each pin individually.

A number of lock picks

Insert the short end of the tension wrench into the bottom of the lock and apply a little bit of pressure.  The idea is to create enough force to create a misalignment in the barrel, but not enough to grip the pin and not allow it to move freely in the pinhole.  Finding the right amount of pressure is a trial and error endeavor and you’ll get a better feel for it the more you practice.

Insert your pick into the top of the keyhole and feel your way back to a pin.  I prefer to start at the back and move my way forward.  This gives you an opportunity to count the pins on the way back.  Once you find the pin you are trying to trigger, push it up slowly.  You will feel a faint click from the pin.  This click is the top portion of the pin leaving the barrel, allowing the break in the pin to align with the break between the barrel and the rest of the lock.  Since you’re applying pressure to the barrel, when that break alignment occurs, the barrel will twist ever so slightly, causing a misalignment in the pinhole which forms a lip that the upper portion of the pin will rest on.  You’ll do this pin by pin until all the pins are resting on this lip.  At this point, what you’ve essentially done is simulated inserting the key into the lock and the barrel will freely rotate, unlocking the door.

Alternatively, you can use a rake pick (which looks similar to a saw) to pick locks, if you aren’t so good at picking locks yet.  Just making a sawing motion back and forth until the barrel rotates freely.  This won’t work for every lock, which is why learning with a half-diamond pick is preferable.

Picking Locks with Improvised Tools

The methodology of lock picking doesn’t change, just the tools.  As difficult as lock picking can be sometimes, using improvised tools makes it that much harder.  As far as the tools go, you can use anything that you can think of to do the job.  You essentially need something that fits into the bottom of the lock that won’t bend, and something to stick in the top of the lock that will give you fine manipulation.

For a tension wrench, you could use a small flathead screwdriver, a large flathead screwdriver with the end filed down, an allen wrench with the small end filed down, etc.  The two most common items used as a pick are paperclips and bobby pins.  To use a paperclip, you just need to make a 90 degree bend very close to one end, or if you have access to needle nose pliers, make a very small loop at one end.  You don’t need to do anything with a bobby pin except to break the ball off one end.

Bumping Locks

A 6-Pin Bump Key

By far, the easiest way to “pick” a lock, but requires very little skill and no finesse.  Modern lockpicking enthusiasts frown on this practice, but in the P.A.W. nobody cares.  This may not be a feasible technique in the P.A.W. because you need a bump key, also called a 9-9-9 key, configured for the number of pins in the lock you’re trying to bump.  If you don’t have one of these ahead of time, it’s going to be close to impossible to get one after Armageddon.  A bump key is just a key with the valleys cut as deep as possible (the setting is 9, hence the 9-9-9 key) and a number of valleys equal to the number of pins in the lock.

Place the bump key all the way into the lock and the pull it out until it clicks once.  Place a bit of pressure (about the same as if you were picking the lock) on the key and then hit it with a rubber mallet.  This will force the key into the lock all the way and jolt the pins all the way up, allowing the barrel to rotate freely before they come back down, giving you free access to the other side of the door.

This won’t work on all locks, and a lot of lock companies are now marketing “bump proof” locks that make it harder to bump the locks.

Doomsday Ark

Back in 2006, scientists started discussing the idea of a “Doomsday Ark.”  This proposed idea is to create a way to rebuild society should the end of the world come about.  While the idea met with skepticism in the scientific community, it has taken a foothold and was formally presented at a conference in 2008 in Strasbourg, France.

The Doomsday Ark is similar to the seed vault locked away in a mountainside in Norway, which contains seeds for every type of plant we know of so that in the post-apocalyptic world, we can regrow any lost crops.  There is also a similar vault in Great Britain that stores genetic samples for all kinds of life on Earth for the same reason.  The main difference is that the Doomsday Ark would be kept on the Moon.

The initial plan for the Ark is to house hard disks containing all of human knowledge recorded in Arabic, English, Chinese, Russian, French and Spanish.  This knowledge will contain DNA sequences, technological information, agricultural instructions, how to make metal, basically anything that could be used to rebuild civilization.

The initial Ark will last for approximately 35 years, at which time it will (hopefully) be replaced with a more advanced version that will include a synthetic atmosphere which can house living samples of plants as well as the given information from the previous incarnation of the Ark.

This is all well and good, but how do we go about accessing this information.  The plan is constant radio transmissions beamed back to Earth.  There will be roughly 4000 receiver stations that will double as supply stations that contain supplies for any survivors.  The problem here is that if these stations are publicly known, they can become the target for anarcho-terrorist groups who decide that having that knowledge would be bad.  The other problem is that these facilities will be susceptible to any disasters that may befall the planet.  However, since it is a constant broadcast and assuming it transmits in the clear, anybody with a radio can pick up the transmission and get the information.

Just another reason to have a radio on hand for the apocalypse.

Found on the Internet: Brewing a Cup of Coffee Without a Percolator

Yet again, Lifehacker shows us an interesting way to do an everyday task in an emergency situation.  This time it’s how to brew an “emergency” cup of coffee.  A first world problem to be sure, but something that could soothe your soul post apocalypse:

So you’re desperate for a cup of coffee, but you don’t have a coffee maker nearby. If you need to get your caffeine fix as soon as possible, you can hack together a small coffee maker out of just two paper cups and a filter.

[Brew an Emergency Cup of Coffee with Two Paper Cups and a Filter] via Lifehacker