First you ll choose your product series.
Build your own outside wood furnace.
Build your own outdoor boiler here.
Remember that welding such thick materials is quite different from welding 1 8 steel because proper penetration is paramount to your success.
You can certainly build a clean burning outside wood burning furnace given access to the right materials and sufficient welding skills.
It is really just a steel box inside of another steel box.
To start there needs to be 3 pieces of 1 2 steel laid out for the bottom of the furnace.