OMG a plaastic radiator, leaking

Does anyone know how to fix a hairline leak in a plastic radiator? It is cracked where the seem is on the little bracket for the screw to go in is at ???

Take some good advice...replace the radiator and save yourself a lot of headaches. Really hard to stop a leak in a plastic radiator. I tried a number of times on two vehicles...nothing worked for long. New radiator should be available for 100 bucks or less on ebay. That is MY suggestion.