How to design hatches?

[forestjohnson]

I need to design some new hatches for my 32' Forest Johnson. The hatches that are in it now are very poorly designed, rainwater goes straight into the bilge instead of out through the scuppers. What sort of options do I have? Should I make a mold to fabricate these hatches. What about the lip the hatches rest on? Could I route a lip in the foam core I plan to use and then glass it or do I have to make a mold for that floor section also. If you could provide any pictures of your ideas I would appreciate it. Thanks in advance, Mark.

[marshmat]

You've already ruled out buying commercially made hatches I take it?

[forestjohnson]

No I have not ruled out commercially made hatches, but I have been unable to find any large enough for the engine compartments and the fishboxes. The only ones I have seen are aluminum and cost a fortune. I think I will try to construct a mold and make some on my own. My question is what design should I use for the lip of the hatches so that they will be waterproof or at least mostly waterproof.

[TrunkCabin41]

Log onto Bertram31.com. Click around. They have a CD (@ $46) on hatch building.

Ford

[drs3317]

forestjohnson,
I'm working on the same project and was wondering what ideas you come up with? I tried to locate the cd at Bertram31.com b ut was not able to locate it. If you find a direct link please post it. As of now I was planning to form a channel of aluminum and offset it lower and use a level floor.
Danny

[forestjohnson]

Here is the link http://www.bertram31.com/subscribe.htm Let me know how you do. I am working on a plug for my hatch doors right now. I'll let you know how they turn out.

[RSLOOP]

My wife and I constructed a fiberglass lip for a Lewmar hatch and installed it on a wooden 1924 sloop. I started with a female mold of the deck and built the plug on that surface. the new deck had an overlapping 1/4" portion and a 1/2" lip to mount the aluminium hatch. In that lip I glassed in stainless steel "T" nuts eliminating the protruding nuts on the under side. have a look in the"RSLOOP" Gallery.
You might note that I had to cut two deck beams, hence the 6" deck overlap. The forward and aft beam of the opening got a carbon reinforcing treatment.
Good luck.

[jbassion]

I gave up on a 'glass hatch and went with laminated teak. Stand inside the hatch opening and work around the hatch clamping (over wax paper) as you go. When it sets, take it off and finish off boat. This way your curves and angles will be perfect.

Jerry