home-made deckplates

I'm getting geared up for my next boat build after the unfortunate demise of my ill-fated first boat (see here: http://www.boatdesign.net/forums/sailboats/hull-shape-simple-sailing-scow-37499-3.html#post490323).

I'm leaning towards using the PD Goose design (basically a 12-food long pd racer). It'll have full-length side air boxes for floatation, and as a cost-cutting measure, I'd like to avoid using pre-made deck plates on the air boxes (I'd probably need at least 4 for the airboxes to be useful for storage and easy to clean out, and at $10-$15 each the price adds up).

I'm imagining square/rectangular hatches made from plywood or acrylic (which can be easily glued with acetone), a lip attached to the inside of the lid to hold it in place laterally and some kind of weather stripping/gasket/silicone something or other to seal the hatch. It doesn't need to be super waterproof, just to keep the bulk of the water out during a capsize to the boat can be righted and bailed.

Has anyone done something like this before? How did you seal the hatches and what did you use to secure them in place? A strap on the outside seems obvious, I've also seen some kayak deck hatches that use a bungee strap hooked to the inside of the hatch.

 

look at what the sea kayak builders make, they have a hatch like you describe held down with bungies. Some can be quite attractive, but will be a lot of effort to make look nice. My favorite design has a weather strip seal round it and a bungie cord holding from the inside, you hook stretch it to hook it on and allow the hatch to snap shut.

You might consider using a large plastic screw cap, like that come on the containers of protein powder. They will not be flush, but will be water tight and cheap (like free). Another thing that might work is a raised lip with a water proof fabric "shower cap" like cover, with an elastic cord that holds on to the lip of the opening.

look around you, you will find something that will work. But do not think it has to actually look like a store bought hatch, and you will find lots of options.

 

I used 4" ABS pipe cleanouts on the Raptor, however they didn't end up being much cheaper than the commercial deck plates I used on the exterior. I've also used plastic storage container tops. Small hatches are easy, but the larger you go the trickier it becomes.