I doubt very much it will hold.
I had 2" crack on top of the radiator. I tried JB Weld and other similar putty but they did not work on plastic. I bought Permatex PermaPoxy™ 5 Minute Plastic Weld from Advanced Auto Parts for $7. It took 10 minutes to finish the job and it worked.
weld it with nylon rod using iron plastic welder.
By replacing the radiator. I've seen people use JB Plastic Weld and it only holds up for a few weeks.
Jb weld expoxy mix
Replace the radiator. Try JB Weld or JB Kwik Weld on the crack first -- you can pick it up for $4 and it is definitely worth a shot. I have tried the jb weld it didn,t work . I had to buy a new raditor ANSWER I work in a shop where we routinely replace the plastic tank. If you have to repair the plastic tank then do it from the inside. You can separate the tank from the core by carefully loosening the aluminum tabs holding it in place.
JB Weld, Seal-All and some Permatex glues
sand the spot to be fixed and used some j b weld apoxy it's sold in walmart in the automotive area.let sit for 2 hours and you are good to go.Improvement done by sickofjunkJB weld is a great idea for a lot of things however getting it to bond to plastic will most likely never happen. That was the first thing i tried on my radiator too but i had no luck with it. To fix plastic on a radiator replace it that is the best way.Or buy a new one that always works out great
you melt it
JB Weld? Drain fluid, make sure it's realllly dry. If it's cracked, smear JB weld or another epoxy compound that bonds to plastic, wait for it to cure (probably 4-6 hours), then refill fluid and see if it leaks at full operating temperature.
One would want to clean their weld while preparing the welds for examination. Cleaning the weld is a safe working practice for welders.
JB Weld
My experience would say no. It may last at first but road condition and depending what part of the radiator tank you put it on, you may be real upset on your trip to the mall or Saturday night out with friends and good old Mr. JB desides to retire