It really depends on what type of plastic you are trying to affix together. PVC is one of the easiest (most pipe glues work). Most hard plastics can be crazy glued. Polypropylenes must be heat welded. If PVC glue will melt it, then you are probably in luck with that glue.
I`ve done the plastic weld thing a little. the problem I`ve had was getting compatible plastic filler. If the filler ain`t darn close to what your welding, it won`t hold.
