Andy Wade wrote in message ...
Pete C wrote:

Does the oil affect the plastic in any way?

I think it can do, with some types of plastic, possibly by a reaction
with any plasticiser, causing embrittlement. I first came across the
advice in the instructions that came with a Ferham plastic (PVC,
probably) cistern and have kept it in mind ever since.

Ah well, in that case I'm going to have problems sometime in the
future !! Firm believer in Plumber's Mait for traps and the likes.
At least I might now have an idea what was the cause.

As a side question - what is the best way of getting taps to tighten
properly onto the bath or basin; previously you could rely on the
stiffness of the copper pipe to help with this but with flexible
couplings and plastic washers I'm finding it difficult to get taps to
lock properly to the bath, etc.

Rob