Try buying liquid cement from the hobby shop, it's like paint that comes in a jar, with a little paint brush (little bit like nail polish), then you hold the 2 piece of metal together, and it glues them together, but it doesn't make string and ruin the plastic.
I know which one you are referring to. But that doesn't bond strong enough ar. I tried that already la. Thanks for the suggestion though. I think I've enough practice now to handle it pretty well.