Forward hatches?

[GordMay]

There is nothing punny about bad puns (unless you composed it yourself); but a good pun is mightier than the word.

[mjt]

Only punks punctiliously punish punnets of non-punformist punsters by punticide.

[Benjamaphone]

There are several 'reversable' mounting hatches available on the market. However, very few are cast out of Almag 35, the BEST alloy for marine uses. In fact, very few are cast at all... often being cheap extrusions.

[GordMay]

The Pompanette “100 Series” Inside/Outside Double-opening hatches, to which I previously linked, are Cast Aluminum Almag-35.
Goto:
http://www.pompanette.com/pompweb.nsf/731d6514ff5a8481852567be000745b2/6cc9c9dafb5c190f852567bc0004e54b?OpenDocument

[Benjamaphone]

nevertheless, few hatches can make that claim.

[Benjamaphone]

Originally Posted by GordMay

The Pompanette “100 Series” Inside/Outside Double-opening hatches, to which I previously linked, are Cast Aluminum Almag-35.
Goto:
http://www.pompanette.com/pompweb.ns...b?OpenDocument

An important point to consider is that the vast majority of Pompanette/Bomar hatches and ports are not cast at all. Most are made by using the inferior extrusion technique. Some true quality hatch and port manufacturers would never use such a weak process in an effort to save money. In this case, look for a hatch/port manufacturer that specializes in casting Almag-35 and carries this specialization through every product on their line.

[Zach]

Dredging this thread back up to the top of the list...

I am fooling around with the idea of making a mold and building a few fiberglass hatches. Had a "Duh" moment a few days ago... Solid modeling programs at my finger tips and a CNC mill up at work. Afternoon or two and I'd have a mold accurate to the thousandth.

Saw some pictures of a Contessa 26 with round hatches that struck my fancy. Seems like a hatch without any corners would be easy to seal. Never seen a submarine with a square one! Any thoughts on climbing through round hatches vs square? I'm tempted to think a sail bag would slide through a round easier than getting caught in the corners, but haven't tried it.

Round would let me lay in layers of roving or uni and build something massive without having to fight the radius of the corners, no built in stress.

Anyone have opinions on fiberglass as a hatch/frame material? Does it expand and contract enough to be a pain in the rump to seal? At the moment I'm thinking to not have any hinges, just a chain and dogs to lock it down. If I do hinge it, set them up so the pivot is above the height of the seal so it locks down.

Figuring a massive wind scoop made out of sheet plastic with a few button snaps could wedge in place, with a shoulder to keep it from exiting the deck at speed. Round hole = point it wherever the wind is coming from.

(Whole idea being I need three water tight hatches, and it'd be more than a thousand bucks if I go with stuff that is commercially available!)

[forsailbyowner]

Ive built a couple of hatches one for my boat and a friends. on mine I was in a hurry and built it out of plywood and glassed all sides. I had to grind the plywood to round all the edges as glass is a pain in the hinney when you try to go around something square.On my friends I made a mold and laid it up sans plywood.The mold was made of plywood and I made the radiuses out of setting type drywall compound. Ive seen the double opening hatches on a boat I built canvas covers for. It had the hinges that had removeable hinge pins. To make them open from inside install dogs on both sides then only pin one side on top and dog the other on the inside.

[Splash Gordon]

I've always liked the idea of hatch hinges doing a decent day's work, as opposed to lurking around letting in drips and shredding passers-by's toes!
I think that the best idea I've yet seen is a Colin Archer-ish boat from Poland with eight of these: http://thumbs.shipstore.com/ss/images/att/att660273.jpg around its forehatch. The idea was that each of the 4 pairs of hinges were linked with a common gudgeon-pin, so that if required, the hatch could be secured along each edge, and by removing three rods, the hatch could open on any edge. There were also 4 Goiot ali handles on the hatch, so that no matter which way it opened, the opening edge could be dogged, and opened from the outside, too. Just my $.02-worth!
Encouragement for Zach: A round hatch might be a little more difficult to achieve this arrangement with, but opening in one direction only's fine: most of the sportsboats I sail have a 500mm round hatch in the foredeck: the idea is exactly ease of sail-handling! And if you're a not-so-runt-sized foredeck-hand like me, somehow the round hatch seems to make sense when combined with my lack of corners!

[Weyalan]

I recently replaced the large (20" x 20") hatches on my boat. I wanted to use Lewmar Offshore, but ended up going with Maxwell Weaver hatches... they carried the same approvals as the Lewmar, were about 2/3 the price and have 4 locking dogs (which I like). I am very happy with the results (although time, of course, will tell).