On 20/05/2021 12:04, David wrote:
I have some moulded plastic fitting in my caravan which have proved flimsy.
I need to both repair and strengthen them.
As a first check, should a fibreglass repair kit - that is, two part epoxy
resin and some fibreglass matting - be suitable for this kind of repair?

Try to find out what the plastic is. There may be a symbol moulded into
it. If not, you could try Floplast SC250 solvent cement or similar, an
internet search will show you loads of suppliers.

A picture of the fitting might be helpful. If it's a plastic called ABS,
then the above will fix it "as new", and allow you to stick on more
similar plastic as reinforcement.