In the interest of DRY BERTHS and other good things...
I'd first peel/scrape off the silicone sealant
. Often it just peels from lexan
and plexi. Then, because the silicone often leaves residual oils, use an appropriate solvent cleaner, i.e. 3m "Prepsolve" used to remove silicons and waxes before paint
jobs. The solvent needs to be something that won't attack the plastic but will attack residuals.
After the solvent, follow the instructions for the adhesive
alone sometimes just embeds residual solvent--so you prep clean before any sanding
. Then prep clean again to get rid of any sanding dust. The adhesive may require that a special primer be used, and they're usually not cheap
but if you skip them, the adhesive may not work properly.
Once you find out what the proper adhesives are, whether it is what GE (makers of Lexan) suggest, or what Goiot
suggest, whoever, the rest will be detailed in the instructions for that product. Anything from the top names should do the job and do it well, if they are followed, and if the hatches were originally built properly.
As to why they leaked in the first place...We'll blame that on the usual suspects. You didn't hold a proper wedding, didn't place a gold coin under the mast
step, didn't make adequate libations, so Poseidon is reminding you.