Not everyone has access to heavy gauge steel or to welding facilities. Part of our research is to investigate "no-weld" methods for producing fuel grade wood gas.
One such method is the use of ferrocement, a composite material of cement and wire or mesh. An effective gasifier could be built from cement with wood formers to hold the cement in place whilst it cures. The gasifier would be reinforced with easily bent strategically placed steel bars. Steel tubing for air intake and gas output could be accurately positioned before the cement was added.
Such a gasifier would lighter than the equivalently sized all-steel gasifier, would be as strong as steel and free of gas leaking holes. Many ocean going yachts have been made with ferrocement hulls and are a testament to the strength and flexibility of this material.
Online instruction booklet - Low Cost Charcoal Gasifiers for Rural Energy Supply