How do you use J-B Weld to work on plastic?

WaterWeld will patch holes and cracks in almost anything.It's ideal for repairing plumbing, fuel tanks, tub and shower, drain, pool and spa, boats and potable water tanks.It can be drilled, tapped, filed, sanded and painted after curing.The set time is 25 minutes and the sets hard in one hour.WaterWeld will cure to an off-white color and can be used at temperatures up to 300oF.