Extra ultra super glue.
Just a useful trick. Some people use the word ‘hack’ for stuff like this, but I … don’t.
However, I will say that I have found that super glue, by which I mean cyanoacrylate glue, is lousy for fixing the plastic that most kids’ toys are made from. However, some companies now sell a double-pack for fixing that kind of stuff — it’s sometimes called ‘Toy Fix Glue‘ or similar.
You can buy it, but it costs a premium, and what is in the pack is a felt-tip marker filled with MEK or something very similar, and a tube of what smells a lot like super glue. Now, you’ll pay something like $10 for this tube of super glue and a few ml of this primer. It works, though.
But, instead, I prefer to pay like $2.50 for a multi-pack of no-name super glue and then go to the plumbing section and get a container of primer for joining PVC pipes for about $6. Now, this primer can be coloured, so it’s a good idea to get the transparent, colourless one.
I use a paint brush, like a cheap watercolour brush, to pain the primer onto both surfaces to be joined. Then I let it evaporate off, and apply the glue to one surface and then hold the surfaces together firmly for as long as possible.
This fixes plastics that super glue won’t normally bond, as well as ceramics — I’ve glued up teacups that have then been used for years, though I don’t put them through the dishwasher. Probably could, but don’t.
Use in a well-ventilated area!
Some plastics will be softened by the primer, so avoid applying more than necessary, and if it is a really valuable/valued item, maybe ‘do a test in an inconspicuous area’, as they say.
Super glue is dangerous and must be kept away from skin, eyes and any other body parts, whether your own or those of other people.
Keep out of reach of children, and don’t let them touch the glue either.