[Rhodes22-list] R22 installing portlights and hatches

[Graham Stewart]

I am interested in installing new portlights and a hatch over the head and I
am wondering if anyone has installed either in their boat and if so, what
they used. I notice that most makes specify the surface must be virtually
flat with a variance of no more than 1 mm. 1 mm is virtually nothing and
certainly my boat has curvature that far exceeds that for both the ports and
the hatch. I don't want to pay a fortune for equipment that will leak. 

Does anyone know what the original equipment make is?

Thanks

Graham