On Jan 19, 7:11*pm, Another John wrote:
Hi

I have various pieces of external downpipe, waste pipe, guttering etc
which are black plastic. Some of this has faded over the years, and I'd
like to paint it if this is practical. * In fact I *have* painted pieces
in the past with ordinary gloss paint: it looks great for about a year,
then starts to flake off.

Does anyone have experience of a product that is designed for painting
plastic pipes?

I am surprised. I have painted grey and white wastes without any
problems. I am pretty sure that grey waste is the same plastic as
white (but white is different, and softer).

Try really careful cleaning?