David why don’t you call some wrecking yards? Tell them what make and model your car is and the engine size and see if they have a used radiator and if the place you call doesn’t have one they can put out a search to all the wrecking yards to locate one and it will probably be a lot cheaper. On the other hand I personally have never found anything that will stop a leak for very long, it may do it for a while, but after a while it begins to clog up the whole radiator and could wind up damaging your engine. It is best to get a radiator without any leaks.