Why is it harsh to make it out of cardboard?

Woulden't it be the same as like a metal pipe or something?
666300 Reviewed by 666300 on . ?'s about steamrollers and Lungs Can you make a steamroller by taking a paper towel roll and puting a bowl on the top. can anyone tell me how a lung works. A bong thread said it was a bottle with the bottom cut off and a bag taped to the bottom. Rating: 5