I wouldn't recommend it as a permanent fix, because as it should be obvious, one good overheat could mean a new head gasket if your lucky, or much much more if your not.
Engine isn't overheating or anything, but what is the best method to repairing this small crack.
Now it would be real nice if it holds til I get the new radiator.At this point remove tape, and keep the chemical within the square.I will post back here if it does or does not.Refer to individual product packages for more temperature information".Epoxy is stronger then the plastic used to make your car.It worked like a charm on my other car, and so as with this one from yesterday.However you do it I wish you all the best.Give them a call before you make the trip down there to avoid wasting your time.Get a large tube, just in case the crack is larger than you expected it.Try to get a replacement that doesn't need a cap.While looking for plastic radiator repair info, I did find this link to a place that sells the welding tool that melts the plastic and the plastic filler sticks to thicken the weld and make it stronger.No problem, tighten it up a bit.Why they make plastic radiators?If plastic can withstand system pressure so can the jb weild.Locate the leak and dry the area as much as possible.Good luck with your problem and I hope this helps.But if ya gotta make it until next pay-day, or until you can find/get a new one.The best answer is to just keep adding water till you can afford to replace the radiator.I got rid of the aged plastic and moulded the area with Sugru.Madrasi, It sounds like you patched radiator with coolant still.It took 10 minutes to finish the job and it completely sealed the leak.
Since you have fiberglass cloth, it doesn't hurt to put some over the crack and epoxy it in place.
Sorry, I don't know if I sent this to the wrong person earlier.