I've recently taken delivery of a wonderful Rowbotham G/C Liliput. It is glorious in every way, except that one of the bass button squeaks. It's somewhat like having a chipmunk in the band.
Any suggested fixes? My inclination would be to colour the shaft of the button with a "lead" pencil (i.e. graphite), however I would welcome expert suggestions before I dive in.
Before attempting any cure, you need to find out exactly what is causing the squeak. It may, or may not, be the shank of the button. Squeaks can also be caused by the rubbing of the coils of the spring in the action mechanism, or the spring ends rubbing on the lever arms, or friction in the 'bearing holes' which the mechanism axle passes through.
With the bass plate removed so you can access the action, try placing your finger lightly on each of the suspect parts while working the offending button, and see if that silences the squeak. You may even be able to hear and pinpoint exactly where the squeak is coming from.
Graphite is a good idea as a lubricant but don't use ordinary pencil lead; it contains a clay filler which can be abrasive. Instead, use pure graphite powder sold as locksmith's graphite lubricant.
Like this. Mix a bit of graphite powder with some meths or isopropanol and apply to the suspect part(s) with a small artists paint brushor a cotton bud. The alcohol will carry the graphite into the narrow spaces and then evaporate, leaving the graphite in place.
Or use Theo's PTFE spray suggestion. (I've not used this myself, but if Theo recommends it, it must be OK
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