Cherry Jam Spirit Lamp: Keith Johnson makes a simple tool to blue clock parts

摘要

I am building a Congreve Rolling Ball Escapement Clock and I will soon be on the finishing process. This is the time when all of the brass parts require to be polished prior to lacquering. The steel screws in particular require the heads to be polished and then 'Blued' by heating over a soft flame until the correct colour is reached. At this point the screw is quenched to halt any change from the colour chosen. This clock has about 80 screws, either 10BA or 4BA size, to be treated prior to final assembly.