Tap with rising spindle spinning around.
The cold tap handle on my bathroom sink just kept turning round without turning the water on. Local plumber said that the serations had worn (probably through turning off too tightly). The original tap was a small tap with non-rising spindles. It was replaced with a slightly larger tap with rising spindles i.e. a long neck on the screw/handle. One day later the whole tap was spinning around. Local plumber came back and tightened the plastic nut. He said he couldn't use a metal nut for fear of cracking the sink. He again blamed over-tightening and advised us to switch the tap off more gently saying it would drip for a while but gravity would ensure that any drips would soon stop. This we did but two weeks later the whole tap is spinning around again. Local plumber again blames over-tightening. My point is that we have not tightened this tap any more than the previous tap with non-rising spindles and that lasted 15 years before the serations eventually wore out. Could the tap itself be causing the problem as apparently the rising spindles mean that it is fixed to the sink as part of the mechanism and doesn't have serations or is he trying to explain away poor workmanship?