I use Plastic weld? Comes in a brown bottle. About £3 or less from a good model supplies or exhibition. https://www.wonderlandmodels.com/products/javis-plastic-weld-57ml/ Is one example.
Thick cyno works well, I know of someone who used it to stick a fake 23rd rail to his layout, using thin plastic stuck to the sleepers without any issues, been there quite a few years now as well.
Thanks, Paul and Andy, I have a variety of adhesives; a Plastic Weld by EMA Model supplies; 3 types of generic liquid SuperGlues; Revell Contacta Liquid, that purports to "bond all plastic parts reliably and effectivley", as well as Humbrol Liquid Poly and tubes of plastic cement. None of which 'hold' the items to be joined. I do have a small tube of Loctite Power Flex Gel which states that it works on all plastics - "Except polyethylene (PE), polypropylene (PP), car glass, Styropor® and synthetic fibres. ", so I'll give that a go and see what happens... and report back!
Have you had a look at plumbers pvc/abs solvent glues? They tend to be more effective on awkward to weld plastic materials. Cheer's, Pete.
Thanks Pete... I'll get some when I venture to the 'Big Store' in town on Thursday, too hot at the moment to move outside for a minor purchase...
Well, I have now actually used the Loctite Power Flex Gel to tackle the 'problem' and after 2 days, the bond appears to be satisfactory. This doesn't mean that it took 2 days to set but after 2 days of intermittently checking the bond I am happy to use the Gel to make the glued joints and fit in a place where maintenance will be difficult... So after lack of success with other cyanoacrylate glues, I will use this again in future 'sticky' areas... My thanks then to Paul-H for pointing me in this direction. (I did not try the pvc/abs solvent, but will bear it in mind, if all else fails!)