Sealing plexiglass, stop-holes?

[fmworth]

There is a glue used in RC airplane assembly for attaching clear plastic canopies. It is called RC 56 canopy glue and comes in a plastic squeeze bottle. It is milk white and dries to crystal clear when hard and is flexible after hardening. I have used this in place of silicon rubber as a sealant as well and works great. Find it at your local airplane hobby shop.