On Monday, 30 November 2020 at 14:44:13 UTC, Andrew wrote:
Has anyone done this ?.

I have a 22mm bending spring intended for 22mm copper
and it is a fairly loose fit.

I was going to heat the pipe with my hot air gun
and bend it around something round or maybe
hammer some nails into a bit of old plywood and
use them as a 90 degree guide.

I am replacing the gas pipe that was used to run
power from house to garage in 1976 with the correct
stuff, so needs a 90 degree bend at each end to fit
a metre wide path, before re-instating the path
(dug up for other reasons).

Andrew
Why not buy, borrow or hire the correct bending spring for 25mm pvc conduit? If the jobs worth doing it's worth doing right. Personally I'd bury a run of much larger flexible ducting and leave a draw string in the duct as well as the cable you are going to use.