[skyking]

you can make the facility to bend wood easily.
I recently built a curved cabinet in my kitchen, and I used some bending oak to make some simulated rails.
I had a piece of steel ducting, but any pipe that can handle 200 degrees will work.
The "boiler" was a recycled paint can.
https://www.dropbox.com/s/mgn7pyd1pg...54.16.jpg?dl=0
Made a scrap wood handle so I would not get burned when adding water.
https://www.dropbox.com/s/30p9pzb6ok...57.49.jpg?dl=0

Same holesaw that cut the can cut the plug.
https://www.dropbox.com/s/wirb3hhfm8....00-1.jpg?dl=0
Clamped it to a ladder.
https://www.dropbox.com/s/7eopw12qse....49-1.jpg?dl=0
We use these washing machine tubs for camping burn barrels. It could just as easily go over a gas grill, briquets in a BBQ, whatever.
https://www.dropbox.com/s/m93pl3drq7....51-1.jpg?dl=0
What is not shown is, I wrapped the tube with an old shipping blanket to raise up the temps.
My dad's steam box was even simpler but bigger.
20' long 2x6 and 2x8 nailed together to form a 6x6 box. plywood door that swung on a nail.
Plywood end with 1" hole.
couple of 3/4 nipples and elbows to a 30 gallon barrel. Barrels have 3/4 threads in the small bung or at least they used to.
Barrel sits sideways on some concrete blocks. 3 sided to keep the heat. Add water to big bung and cap it.
Start a fire and wait till steam is rolling out of everywhere