The cylinders on steam engines need insulating and there are many ways of achieving this. On this page I’ve shared some ideas and options.
The cast iron cylinder from my wood and metal beam engine with a number of steps designed so that I could wrap the outside in wood and create an air gap.
The wooden planks in the image below shows how these then create an air gap and how the brass caps hold all of this together.
The top and bottom caps were machined from brass. The top cap was bored larger than 1 inch so that it would easily clear the piston – note that this is a single sided cylinder. The hole in the bottom cap is to take the intake/exhaust pipe.
The cylinder was finally clad in bog oak and then two coats of varnish and a sand in between.
The top ring is fixed with three brass 8BA bolts with round heads. The bottom brass ring is fixed with three countersunk 8BA bolts. The three other holes are threaded 8BA and are designed to fix the cylinder to the beam engine frame. The centre hole is tapped 8mm Metric. The idea is to fix the inlet/exhaust pipe here.
For my oscillating steam engine I took a more traditional approach and machined a step in the cylinder outer surface to create an air gap.
A cover was then made from sheet brass and this was then painted red and bolted in place with small brass bolts.