Just going to do the job once and be done with it like every one basically said. Epoxies come in a lot of different forms. I agree there is no substitute for replacing the radiator. This epoxy is NSF certified and can be used on tanks that carry drinking water as well. Correspondingly, how do you fix a radiator with JB Weld? If you’re a fan of J-B Weld epoxies, you are going to love this one. Thanks to everyone for there advice , i decided to go ahead and replace the radiator , i can get one for about 80 shipped to my house next day from a place on ebay. 500 degrees F heat capacity also makes sure that the layer does not move. Once the layer is on, you can rest assured that all cracks and holes are taken care of permanently. K Tool International, Q Bond Adhesive Kit KTI90002. jb weld will work.I used to have 89 civic,radiator had crack about 3 inches long.I drilled a hole in each end of crack with 3/16 drill,then used a razor blade to make a v-shaped grove all the way through crack and roughed up area around crack within 1/2" of crack.Then I mixed up small ammount of jb weld and put in crack area only(not around it yet)I used hair dryer on it about 10 min to semi harden quickly.Then mixed more jb,putting over crack and arround surrounding area.Then later one more layer.Ran like this for 6 years with no problem until car crashed into tree.Dont use jb quik though,its not as good.Somehow tree didnt kill me,I put my arm up and elbow went through windshield,both knees busted dash.All I got was swollen bottom lip!No seat belt,no air bag,I got lucky. That is why getting quick-dry epoxies like this one is the best. I love JB Weld products, but if your radiator is leaking just bite the bullet and replace it. Make sure no water seeps back up through.