GreenLake wrote:(You could, of course, also cut out a slightly wider opening, and then make the additions for the necessary closure mainly on the inside of the opening. Think: adding a lip on which you'll later add some gasket - like the ones used for a non-sliding car sunroof. The upside is, with the right seal, you could get a "flush" appearance instead of a raised hatch. The downside is you would need to work overhead...or turn the boat.)
As your plans solidify, why not run up a sketch or two of your preferred strategy. Better basis for discussion.
I'm baaaaack...
Returning to this discussion regarding possible companionway hatch seals, GL suggested several good thoughts including building an inside lip that would allow re-use of a cut-out deck section as a hatch cover, to remain somewhat flush with the deck while still providing an option to open said hatch, allowing (as my interests indicated) easier access to the cuddy space.
I understanding this is a major modification which may detract from resale value and those things... (as posted elsewhere, I'm not worried about resale value for this particular boat). So going into that part eye's open, I'd like to get some input regarding some ideas I'm kicking around for such a hatch lip/seal.
Again, for this discussion, I'm not asking if it's a good idea to install a cutout hatch, I'm asking for some technical feedback on a hatch lip idea I'm playing with. (for the purposes of this discussion, assume I've already cut the hole).

I've been pursuing two avenues of thought, both of which re-use the cut out section of cuddy roof as the hatch piece.

The first is to build a wood L frame inside the hatchway (boat section) and an inverted L on the hatch cover piece that fits over and outside of the hatchway frame. (very similar in concept to jdoorly's hatch on Desperado) I've been modeling this with pine because it's cheap and easy to work with. My intent being when I have a final design, I'll use the pine pieces as a model to cut hardwood pieces for final finishing, assembly and use. Fortunately (or not... depending on your perspective), the PO had installed about 24 various soft cover snaps around the cuddy bulkhead which I'll need to fill eventually, but for now they provide easy screw tack points for holding my pieces in place as I try various things out.
I'm calling this the "build up" version, and it has come along far enough that I'm pretty convinced I could make it work, but I'm not yet certain it is best way to go. So I'm pausing now to investigate option 2.
In one of the previous posts of this thread (quoted above), GL had suggested an idea for an inside lip that would allow the hatch to remain essentially flush with the original deck shape when closed. I've not been able to build that model out yet, but am getting close, and this is the one I'd like to get some more input on.
My idea is (as mentioned) for a lip/drain/seal based on the concept suggested by GL.

The idea is to make a fiberglass channel with a long lip with which to attach to the inside, underside of the cuddy ceiling. Three sections of channel would be created forming a "C" with the open ends at the cuddy bulkhead. It is shown here as square channel, but I really envision the channel being round or at least rounded corners. The depth of the side channels would start shallow near the mast, and increase toward the cuddy bulkhead so water captured would be drawn by gravity to the drain system which I'll fabricate at the bulkhead down to the cuddy/cockpit drains. My intent is to use a round rubber seal (I'm still thinking of the air conditioning pipe insulation or similar) to provide a water resistant seal between the channel edge and the hatch piece. I may have to mold some aluminum stock into this edge for it to be stiff enough. Might need some input on that.
There also would need to be a clamp system to cinch the hatch cover down equally onto the rubber boots around the edges, but that's phase II, only necessary if I decide to go this route.
Acknowledging that the deck is curved in the lateral plane (but too much work to do for this quick sketchup drawing) I know I'll have to address that curve for the long portion of the C, either making smaller pieces attached in sections and joined, or making a complex mold for my channel that follows the curve of the deck/cuddy ceiling.
Since I've already cut several pieces of wood for the "build up" design that conform to the deck curve, I may already have what I need to make that complex curved mold.
I would intend to add a stiffener/strengthener along the mounting tab of the channel to restore deck strength and would add a wood or fiberglass stiffener around the outside bottom of the hatch piece as well to position it snuggly within the channels in addition as adding stiffening to the hatch deck surface.
So at this point I think I'm looking for some suggestions, thoughts, comments or alternative ideas about the lip/drain/seal channel.
I'll probably start working up that model during the long new years weekend.
Thanks,
DS #6127 - Breakin' Wind - From the land of 10,000 lakes, which spend 80% of the year frozen it seems...