Hi,

My Radiator split on top, the plastic part, it ran about 2 inches but was enough to kill the car.

I drilled 2 small holes at each end of the crack, to stop it spreading. Then I put on a product called "Quick Steel" which I got from Kragen. It's like putty and you just push it into the crack. It goes hard in 15 min but really needs to be left overnight to be the best.

I did this as a temporary fix but forgot about it. It worked really well.

Beware: When it's on and dry, it is very hard to grind or shape. So make it look nice when it's wet!