40 More Handy Tricks

Step 31 Pressurize and Cap an Empty Soda Bottle

Empty soda bottles make good buoyancy chambers in a boat.
But when they cool off they contract and make crinkling sounds, besides losing volume.

Here's the gizmo I use to pressurize them while screwing the cap on. It's a chunk of bicycle innertube attached to a blowgun. The short part that goes over the bottleneck has an extra layer of innertube slid over it to handle the pressure. The long tail has three layers of innertube and is sealed with a knot at the end.

I loosen the bottlecap a turn or so.
Then I slide the short rubber tube over the neck of the bottle.
I grip the tube over the neck ridge and lean the airgun's lever against the table to pressurize the tube.
It puffs up from the pressure and the bottle gets hard.
Then I turn the bottle with my left hand while gripping the neck with my right, screwing the cap tight.



Another method is to put a small chip of dry ice in the bottle and then screw the cap on.
A reader suggests another method, which is put the bottle in the freezer for a while and then cap it when it's cold. When it warms up the air will expand and puff up the bottle.

Comments

[sharlston]

tim,i was wondering the innertube is it a normal mountain/bmx innetrube or a racing bike?

[egoncasteel]

Another way to do this is to use canned air. The type you use to clean computer equipment. Just turn the can upside down and spray a little of the liquid in to the bottle, and put the cap on. Don't spray in to much or the bottle will explode loud as a gun shot a minute or 2 after you put the cap on. (unless you want to scare the crap out of every one in the office)

[dfairlie]

Duh! I totally agree with chilip, I do that ALL THE TIME, its so much easier. In the winter I just leave them out ;)

[chilipähkinä]

Easier way to make pressure in the bottle is to put them in the freezer cap open. Let em cool there for a while. Then screw the cap on while bottle is icecold and when air inside warms up bottle has some pressure inside.