If you have to fit a bush which extends into the barrel as in Figs 1 & 3 and the wear is such the entire existing bearing is removed or severely weakened by the amount of material which has to be removed it is important to remember the diameter of the new bush must be less than that of the barrel arbour. If it is larger it will distort the mainspring as it is wound on to the arbour. (Fig 7 ).
A flanged bush can be made to increase the thickness of the bush which is useful on occasions, particularly in some modern clocks which tend to have thin lids and bases which is one of the reasons they wear so quickly, (Fig 8). If you intend to fit thicker bushes make sure they do not interfere with another component. Riveting or soldering? Which is the best option? This is a personal choice, both requiring the same
level of skill.
How best to go about soldering is a mystery to most and many a dry joint has led to some spectacular failures. However if done properly, which means you know how to solder, the join is as effective as riveting. One of the benefits of soldering is the bushes can be made to the precise dimensions before fitting as opposed to the riveted bush which requires machining after being fitted.
The advantages of boring out the new bushes whether soldered or riveted are that they will always be precisely in line which is the desired result. Practice makes perfect and you will soon get the hang of it. There is something very pleasing about a barrel which spins freely and precisely between your fingers. Achieve this and you deserve a pat on the back, you are well on the way to realizing the rest of the clock has
to be dealt with in the same way.
