building watertight hatches

[theFunsmith]

The weather is turning here in Oregon, and I am looking at many gray months ahead, so my focus will be shifting from the hull to sub-assemblies that can be built indoors. I would like to incorporate some hatches into my deck to access the rear bilge area, to operate the raw water wash seacock and access the bilge pumps as well as one or two up front for the business ends of the gas tank for when service becomes necessary. I have seen some very intricate drain and plumbing systems incorporated into the decks, but am of the mindset that plumbing below deck should be minimized, and that every hose and pipe is a potential failure point. I would like to build watertight hatches if possible, and would like build with dual opposing compression style latches and  accommodate a seamless gasket, instead of cutting one to fit. I may be missing something but I don't see many builds incorporating seals into their hatches. Am I missing something, or is there a reason most do not do this?

[mshugg]

I think folks do attempt to make hatches water tight.  Im not sure how much more water tight, oposing compression latches would be over hinges and a compression latch.  Though another advantage of that approach would be you could completely remove the hatch cover.

In my rebuild the hatches are gasketed, but I don't expect them to be 100% watertight.  I do believe that the gutters and gaskets should minimize drainage into the bilge. 

[RickK]

The hatch I made in the aft isn't working out like I wanted it to as far as water tightness and I'll need to talk to some guys here for ideas.

[theFunsmith]

Rick,

If you do get any info from the pros, I am very interested. I plan on molds for my hatches, but I want to do it right. I'll take as much information on hatch and floor interface specs (optimum gutter profiles and such) as I can get .

[Que Pasa]

If you're making singular hatches, you may want to look into the foam method for ease of construction.

[dirtwheelsfl]

Just built these for a Seacraft. All 3/4 mdf so it was just a matter of ripping on a table saw and mitering.

The troughs are 1.5" wide x 3/4 deep, and the male lip portions are 3/4 x 3/4.    Wasnt much fun to lay up but they channel water great. The lip will create a surface for a gasket seal so they should be pretty water tight!

Untitled by dirtwheelsfl, on Flickr

Untitled by dirtwheelsfl, on Flickr

Untitled by dirtwheelsfl, on Flickr

They drain thru pvc ran under the splashwell and out the transom...

Untitled by dirtwheelsfl, on Flickr

[theFunsmith]

If you're making singular hatches, you may want to look into the foam method for ease of construction.

Thank you for the direction here, I will see what I can find on it. I have no idea what the foam method is at present.

Just built these for a Seacraft. All 3/4 mdf so it was just a matter of ripping on a table saw and mitering.

The troughs are 1.5" wide x 3/4 deep, and the male lip portions are 3/4 x 3/4.    Wasnt much fun to lay up but they channel water great. The lip will create a surface for a gasket seal so they should be pretty water tight!

Those hatches look killer. Thank you for the dimensions and clear pics. Since the Photobucket flop, Finding good photos of in-progress component stuff like this has become a lot harder than it once was.