The same Coke bottle as above but this
time it was re-enforced with a single layer of blue
Scotch "Gaffer" tape. This tape is quite flexible and
provided very little re-enforcing strength. In the video
it is quite obvious that bottle stretched significantly
before bursting. This tape is useless for
Heat Shrunk to 1 L
This was a test to see if shrinking a
bottle using hot air would make it stronger because of
the smaller diameter and hence slightly thicker walls.
The bottle stretched quite asymmetrically and
burst at regular pressure. This bottle also failed
unlike the others. The bottle failed at the neck and
shattered the nozzle. When bottles stretch it is very common for little
stretched "V"s to form right at the base of the neck.
The bottle probably failed at one of these and the crack
propagated all the way to the top shattering the nozzle
Conclusions / Analysis
The most effective reinforcement technique was the glass
The cheap gaffer tape and heat shrinking made little
difference between in providing extra strength.