Joe fixed the impeller assembly on a broken aquarium filter fan with just a little bit of InstaMorph. Apparently the fix was super simple. He just heated up a few pellets and combined them together. While the plastic was still hot, he attached the replacement blade to the assembly, and the plastics bonded together.
Remember, InstaMorph, when warm, will stick to certain types of plastic. In this case, it can be a good thing. For best results, if you can also heat up the area to bond too, this does help.