Try theses glues when making a plastic kit. EMA Plastic Weld good for all plastic parts, and some 5 Min's Epoxy for anything thing else or superglue itself.
you find with many kit you buy they always recommend buying a selection of glues made by them, incressing there profit , when yet its proably easier as well as cheaper to buy these products and they do the job the same if not in some cases BETTER!