Did you know there's a way to start a fire by squishing air? In this project we're building
a tool that does exactly that. And with a little it of resourcefulness we can make this
for under a buck.
The materials for this project cost me less than $1.00. I got these pieces of scrap acrylic
for free, and besides those, all I'm gonna need are a couple of rubber O-rings, a 1-1/2"
bolt, and this handle I got off a lawn mower. This piece of clear acrylic rod fits perfectly
into this tube so I'm ready to form the piston. I'll use a 10" piece of rod and secure it
into the chuck of my drill press. A hacksaw is my tool of choice for cutting a groove
in the plastic rod, and with a bit of guesswork, I've made it just big enough to fit this O-ring
securely, leaving the rubber edges slightly wider than the rod. Next, I'll place the rod
in a bench vise, protected with a terry cloth, and when it's secure, use a 3/16th drill bit
to cut a hole right through the side. It's a clean cut and the spacing is about 1/4"
from the O-ring, so I'll proceed to my chop saw, and make a cut just barely touching the
top of the hole. This has just created a claw that will hold my tinder. It's time to cut
these pieces to length, so I'll mark them at 6", and cut them together. While I'm here,
I may as well cut an inch off of the tubing, and a small square piece that I'll use in
a minute. Ok, I've got all my pieces cut to length, so now I'll remove the protective
paper from this little square, and carefully cement it to one end of the tubing. This will
need to be an air tight seal, and I'm hoping this weight on top will help. With that setting,
I can get back to making the piston. This time I'm using my drill press and a 1/4" bit
to drill a hole down the inside of the rod. My goal is to get the hole as centered as
I can, and when it's roughly 1-1/4" deep, it can be transferred back to my bench vise
for tapping. This is a 5/16th course thread tap, and I'm using it because it matches the
threads on this bolt. To make this handle, I carefully used my vise and a 1/2" drill
bit to hollow out the center, which made a large cavity that I'll be using later. I threaded
this hex bolt all the way in, and then secured it tightly using a pair of pliers. You can
see the handle and the rod thread perfectly together, and will just need to be tightened
by hand. A little acrylic cement is applied to the rod near the handle, then the 1" piece
of tubing is added, and cemented in place by dripping glue into the gaps. This piece
is to help reinforce the area where the handle meets the rod. That's setting, and it looks
like the tubing is cured enough to knock down the base on my belt sander. Just a minute
of sanding, and the base is rounded and looking much better. To help it cure air tight, I'll
clamp it together and leave it overnight. To finish off the piston, all I need to do
is slide the other O-ring into place. And this will help cushion the acrylic pieces
from impact with each other, as well as create a slight gap between the tinder claw and chamber
base. A little bit of lubrication is added to the O-ring, and this $1.00 fire piston
is looking awesome. I even found a little cap that fits perfectly into the handle. I
had enough material to make another piston,
I'm gonna test the small one first
using some char cloth I made in a previous video. I don't need very much and this little
piece should work fine. When that's rolled up, and placed into the grips of the tinder
claw, I'll gently insert the rod into the chamber until the O-ring presses inside. Then
with one swift downward stroke, I've got ignition and my tinder is burning! I'll try that again.
And this attempt was just as successful! By compressing the air quickly enough, the temperature
shoots up hundreds of degrees Celsius in a fraction of a second. Enough to ignite char
cloth and other types of tinder into burning embers. The cavity in the piston handle is
perfect for storing some char cloth, and the cap will hold it in place. To see if this
will work out in the woods, I've readied a tinder bundle made from dry grass, and when
my fuel is loaded I'll give the piston a whack. There it is. I've instantly got a glowing
ember, and using a piece of grass to transfer it into the nest works pretty well. The heat
is building, and this little bundle almost explosively bursts into flames. That happened
pretty fast and before I burn myself I'd better get this over to the fire pit. This bundle
is a little damp, so I'm adding a piece of char cloth inside the nest to help it develop
a flame. And there it is. And it's taking off fast! Yikes! I've been getting ignition
on nearly every stroke, and this is proving to be an easy and fairly reliable way to start
a fire without matches. Some people say this little tool was commonly used in the 1800's
and was the inspiration behind the diesel engine. With this tube being completely see
through, it's exciting to witness the actual ignition point of my fuels, and for under
$1.00 it was definitely a project worth the investment. That's another item for my emergency
kit, and a great way to see science in action. If you liked this project, perhaps you’ll
like some of my others. Check them out at thekingofrandom.com