Step 1: Collect Cans
All of the same diameter
the "old" and "fat" aluminium( Like the Pepsi in the pictures), as the new tall and slim steel cans( like CocaCola) and also the llittle Red Bull aluminium cans...
I noticed that the "slim" ones works a little better...( with the cans in the pictures I had a little "instability" imperfection while with the other kinds I had them perfectly sealed...)
I had only 2 cans
Step 2: Remove the Top of the 1st Can
This is important to help you insert this can in the next one.
Step 3: Remove the Bottom of the 2nd Can
You can obtain a tank instead a pipe:
Instead removing the bottom you can also remove the 2nd top( in this case cut in the cilindrical surface) and then press the 2 cans together you will obtain a tank
Step 4: Insert the 1st Can in the 2nd
Step 5: Press!!
This is the reason why I advice you NOT to remove the top of the second can before insertion... you would have to press on a dangerous cutting edge.
Step 6: Repeat...
You will obtain a pipe...