...as a simple crack on the top CAN usually be successfully repaired with JB Weld or the green (needs to be "kneaded") radiator repair putty.
The key is to use a Dremel and drill holes at each end of the crack so it doesn't get longer, then use the tool to enlarge the crack itself to about
1/8th inch: that way the repair goop can "mushroom" on the interior side. You also want to wipe the plastic with acetone or some other solvent to get a good bonding surface for the goop the seal. Let it get good and dry 1st.
You can then add a second layer on the top.
Good luck!
