It does depend on the type of plastic , some of the waxy feeling type are notoriously difficult to glue up.
If you have this type then can I recommend a product called MILLIPUT, this comes in three colours ,red, yellow, and white , there is also a forth colour white but fine, this is good for the repair of fine china (but not handles in use)
Scratch the plastic so as to gain a grip with the Milliput and use as directed.(Even drill a few small holes for increased grip if it is convenient)
This stuff is also great for temporarily fixing leaks on pipes and radiators etc, without draining down.
Good hardware stores hold stocks.What is the best adhesive to use to bond plastic and metal together?
The correct glue depends on just which metal and which plastic you are dealing with. Polyethylene is particularly difficult to glue. Companies like Loctite (owned by Henckel) produce compatibility charts to help you select the correct glue.What is the best adhesive to use to bond plastic and metal together?
Depends what your sticking together - could be as simple as superglue but could use 2 pack cement
contact cement brushed on both surfaces...