This is a project I done over a weekend, it's a mini cement mixer made from old recycled parts, I used a bicycle frame because it has a crank and two axis, one that turns and one the steers, I use the crank to power the mixer and the steering to tilt the mixing bowl forward making it easy to empty out the mix,
You can check out a video here of the cement mixer in action.
https://youtu.be/I63l_SrT2yk
I do not recommend you use any container that was used to store gas, lpg, butane or propane gas, gas bottle / container / tanks or any pressurised vessel should not be tampered with, high risk of serious injury and death.