Geoff Pearson wrote:
The mother-in-law has brown ("mahogany") uPVC windows and front door
installed about 22 years ago by C R Smith. On the sunny side of the
house the surface "varnish" is peeling away and we would like to
re-finish. Ronseal and Dulux sell UPVC paint in white but it seems
too risky to try to convert from brown to white. Any suggestions for
a suitable varnish or lacquer to restore the look?

Geoff

The 'varnish' you speak of isn't anything that comes out of a bottle - it's
sticky backed plastic, better known as 'foil', you can scrape off what's
loose and colour it in with a brown permanent marker (which is what
manufacturers use on welds) but the finish isn't going to be very good and
it will need re-applying when the sun bleaches it