The Loctite plastic bonder doesn't work well for polycarbonate sheets in my experience.
You want Methylene Chloride. It can be expensive, but you don't need a lot to make the bond. You will need a syringe to put drops of material along the surfaces to bond.
http://www.ehow.com/how_5686551_glue...ate-sheet.html
http://www.ehow.com/how_6635889_glue-lexan.html
http://www.mcmaster.com/#catalog/119/2120/=ldfxxn would need some additional chemicals added to the mix to make it easier to work with.
I've had experience with Weld-On #3 such as this:
http://www.eplastics.com/Lexan_Polycarbonate_Glue