The Stew Adventures Part 2

[Dafty]

I want to make a video but I'm stuck...

Spoiler below!

On the first place I find the rope the fool the key the acid liquid thus the switch for the cannon , the boomboom liquid, also find the drill and use on the pipe with the hammer for get 2 little piece of pipe.
But now I don't know what do... I noticed that the 2 "legs" of the cannon can be clicked ( hand ) but I used all objects I have and nothing happening.... What should I do ?
Thanx and sorry for my english. By the way if I find I'll prehaps make a video