BUILDING A

METRIC MINNIE

Part 20 by Franco Pucci

Pressure test, painting and lagging


Oh, no! Not the pressure test...


The setup I used for the pressure test. The working pressure of the engine is stated to be 3 Bar, so I needed to test to at least 6.

I filled up the boiler with water until it almost overflowed, then cranked the hand pump until I got to 7 bar. Some very minor leaks on the fittings, but no explosions or ruptures so I was happy with that.


Painting the boiler before lagging could commence. I used automotive two part paint for the entire engine. Matt for the boiler and firebox (the black bits), and gloss red for the rest.


Front wheels painted.


The painted rear wheels.


And the flywheel.


The rest of the painted bits, ready for assembly.


Rear wheels on, and the lagging glued in place, ready for the wrapper sheet.


The template for the wrapper sheet - used 0.2 mm brass sheet for this. The straps were made from the same material.


Wrapper mounted. All that was left now was to fit the rest of the parts and give it a test on compressed air… and boy was I nervous about that.


Part one here  Part two  Part three  Part four  Part five  Part six  Part seven  Part eight 

Part nine  Part 10   Part 11  Part 12  Part 13  Part 14  Part 15  Part 16  Part 17  Part 18 Part 19 Part 20  Part 21