Super super-glue
We have external roller shutters on all our outer windows (these are common on Germany, but quite rare in the UK so if you don’t know what I mean take a look here).
They run in a slot which is part of the window frame, and at the top of the slot there is a piece on each side like the photo – it acts as a guide to make the shutter’s slats run easily into the slot without jamming. The guide and the slots are made of polyethelene or some other low energy plastic (low energy plastics are non-stick like teflon, and are correspondingly difficult to glue – super-glue doesn’t stick at all, for example!).
The problem is, that the guides get loose and pop out of the slots, which means the shutters jam. We have had a firm come in, some years ago, who glued them all back in. But the glue didn’t hold and for some months our bedroom shutter has been completely jammed after a long period of playing up on occassion. Now the weather is warmer, we decided to have a go at fixing it ourselves. After some research on the internet, we found that there is only one sort of adhesive for these problematic plastics – 3M’s Scotch-Weld DP-8005. It is pretty expensive – we paid 25 Euro for a 38 ml tube of it, and another 60 Euro for the gun which is neccessary to apply it in the required 10:1 mixture (its a two component adhesive). But it seems to have bonded the guide to slot very effectively and the shutters are now working properly again. We bought ours from shopdepot24, who delivered by return of post and also pointed out that our original order was missing a vital component, so we could change the order before it was shipped. Both the supplier and the product are to be recommended!