Hobby Casting
Holes are cut at opposite sides for burner & exhaust.
Bugger.. the smarter among you will have realised that a tangential exhaust cannot have a centrally cut hole. Bah !
The ball of paper wrapped in tape at the centre is to form a chamber in which to burn the oil.
The Bluram works like stiff modelling clay. Tomorrow my shoulders & upper arms will pay the price.
The 18mm copper pipe forms the opening for the oil drip.