Hull with deck mounted:
From Phil Geren:
The simplest hatch cover solution I have found for Star 45 is to cut a piece out of Presentation Cover vinyl, which cut-out is shaped like the hatch opening but 1/4 or 3/8 of an inch larger on all sides. Then, apply electrician's tape (1/2 or 3/4" wide) all around the perifery, so that half the tape is on the vinyl and half is hanging over the edge.
Presentation Cover vinyl which I get at Office Depot is about 15 cents a sheet; it is about 0.008" thick; it is slightly over 8.5X11" in size; a full sheet weighs about 16 grams; it is stiff, but flexible; it is crystal clear, but if you want it opaque, just wet sand it with #400 grit wet or dry sandpaper.
Position the hatch cover over the hatch so that the tape extends evenly past the hatch opening an equal distance all around, and then just press on the tape to stick it to the deck. It's waterproof, durable.
You can make spares and stick them to another piece of vinyl and carry that with you to the races. That keeps spares nice and flat and keeps the tape's sticky side clean for future use. A set of these hatch covers usually lasts me all season. At lunch, I take one cover off to allow the boat to dry out, sticking the cover to a dry vinyl sheet to keep the tape's sticky side clean.
Photo is Star 45 #778, freshly rebuilt for the Nationals this year, and a set of covers on the floor next to her.
from Uncle Dave:
I pulled one of my old Star45's from the attic and have it here in my workshop. It has a fiberglass Sirius 45 hull, a aircraft ply deck and aluminum keel fin. Unfortunately it is not one of my finest examples of workmanship or painting. However I'll suffer the embarrassment and use if to show some one style of hatch construction.
Carrying around a model around out of the water is no big deal. Taking a model out of the water can be something else. You first need to hang onto the model. Then find a place to take hold to lift the model. This is one of the reasons I have used easily removable hatches. You can grab the model through the hatch, fingers under the deck and pick it up. Of course a thin ply deck the model deck and hatch construction needs to be strong enough to withstand pulling on the deck and lifting a twelve pound plus model. Therefore I braced my decks around hatch areas.
First I built a flanged frame for the hatch to sit in that also extended under the deck and attached to the deck bracing.
Then I built a hatch cover based on the size of the hatch. Initially the hatch cover was made to fit very loosely in the hatch. I then took some silicone (tub seal or similar) squeezed a bead around the shelf/lip of the hatch. The covering the hatch opening with food wrap poly sheeting I'd push the hatch cover in place down into the silicone. This made a nice water tight gasket around the edge of the hatch. After waiting a day I'd remove the plastic, trim and silicone that showed topside. With the silicone dry, pop the hatch cover in place and check the fit.
I placed a strip of magnetic tape on either end of the cover and on each end of the hatch frame.
When the hatch cover and hatch mag tapes touched they pulled together. This magnetic tape is neat stuff you can pop the cover in place and it will stay put.
Typically I made my hatches about 4"X5" giving me plenty of deck to the sheer.
I heavy weather if the model might go over on beams end I'd cover the seams with tape just to be extra watertight. A 4X5 hatch gives room to get inside, adjust winch, radio etc, and to remove any water that got into the bilge while sailing.