It may have been on here before, but I'm part way through building this rocket stove
http://www.thediyworld.com/DIY-Rocket-St...ur-Own.php
I have the large tin and the vertical inner ones already plus the cat litter.
I got a catering size tin rather than a coffee tin as they are stronger. The vertical section is two Branston baked been tins (other brands are available!).
I just need to find a longish but smaller diameter tin for the horizontal part now.
I will update when it progresses a bit further.