Yes, It's very tricky and takes time to do it. Process called Thermo Welding. There is many DIY guide on the internet. basic 101 about thermo welding...
You have two options.
1st option is to buy professional plastic welder kit (starts $50-$300) that will melt plastic parts and fuse it back as one new solid part.
how does it work!
Simple you heat whole area where plastic welding will place, then once you reached required temperature for the plastic that you weld, use your plastic welding gun and the plastic ROD (ROD is new material that will be added to the welding process)
BTW very important you can only weld SAME type of plastic together, mixing it with other types of plastic may cause bad results.
Once you have both radiator and new ROD heated they will slowly join them self.
This is not easy but works,
2nd option: instead buying plastic welder you can try to use adjustable temperature or none adjustable soldering iron. On none adjustable soldering iron you have to play with the distance of the tip so you always have same temperatures on the part's it's very important to reach correct temperature for this to get successful results.
I hope this little info will help.
Boki
Jb weld expoxy mix
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.
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.
By replacing the radiator. I've seen people use JB Plastic Weld and it only holds up for a few weeks.
I doubt very much it will hold.
It may work as a temporary fix.
If the radiator cracks on top or bottom (bolth sides are plastic) ........ replace the radiator, can't be properly repaired.
On top of the radiator under a black plastic shield.
Replace the radiator. It is plastic and cannot be repaired.
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
If the seam is coming apart, use J B Weld between the parts and then if possible screw in 2 small self tapping screws through both parts at each end. This should pull the parts together, then finish off the top of the seam with J B Weld also.