Ideally, a band saw is what I use.
As 6PTsocket stated, I have scored the plastic, both sides with a carbide blade, takes a while..use a taped/secured straight edge, works OK.. esp. thinner stuff.
Use a sharp edge for the final break- while clamped.
A variable speed jigsaw MAY work, if it's well clamped -close to the cut.
After that..for a straight edge, a belt sander is ideal, other than that..good old sandpaper, then finer "wet & dry" sandpaper on a glass/flat surface.
For a fine finished edge, use the wet & dry sandpaper - wetted, 120 & work to ~200-400-ish grit, then for a very nice edge finish, use plastic polish (I use Novus, good stuff - fine version works well- also works very well for your dull plastic car headlights).
To glue it, use methylene chloride, hold the edges together & apply dropwise with a ~18-20 Ga needle syringe to the very edge (careful not to slop, as it will dull any parts you don't want it on) & hold it for ~30 seconds.
Methylene chloride is available at plastics shops..and also some neon sign shops..don't need much at all- 100ml should be more than enough for a few small projects!
And keep it well sealed..it evaporates like nobody's business!
G'Luck!
