I think a lot depends on how you want the hatch to be sealed. If you are happy enough with a sealing lip glued underneath your deck and the piece you cut out sitting back inside its original hole, there should be little problem.
The trouble I had was that I was never happy with this idea and there are several reasons for this.
1. The hole needs to be cut perfectly for the thing to have any chance of looking any good.
2. The sealing lip underneath your deck effectively reduces your hatch hole size.
3. The gap between your hatch lid and deck creates a space for water to accumulate while paddling and unless your eai perfect, thiwater wll find its way into your storage.
To overcome these things, there are two alternatives that I can think of.
1. cut a strip of ply slightly igger that your hatch lid and glue it to the top side so that it overlaps the gap between lid and deck. This is what I did and i found the process changed the shape of the hatch lid and it no longer fitted neatly against the deck.
2. Cut a new hatch lid, slightly bigger than the hole you cut in our deck, build up the deck like a sort of cockpit coamiming lip and to the same to the underside of the lid. (Like I do on multi panel decks) This works well for me but I haven't tried it on a rounded deck.
The advantage of the rounded deck, is that it can be cut and fitted to your hull in one piece and this saves a LOT of time during the initial build. All this time saved is/was lost for me in struggling with the bloody hatches, trying to get them to look even half way decent.
For me, a poorly fitting hatch is like a less than perfect mitre joint in a picture frame. It looks horrible and detracts from the beauty of that which it is supposed to enhance.
Others have used this method to very good effect but I lack both the skill and patience to be bothered with doing it again, just for tte sake of having a rounded deck. i don't like the rounded decks that much anyway.
When I do a hatch ... I mark it out so I know the exact shape of it and position. Then I drill 5 -1/16th inch holes touching each other , this is where I start the cut.
Using a Bonsi Saw I got from CLC I cut out the hatch. ( the saw has a very fine and thin blade ). Any mistake made will look like the hatch since the piece cut out will go right back where it came from.
After it is cut out then I attach a strip to the underside of the deck and it is positioned so half of it is under the deck and half of it is into the opening the hatch was cut from.... this makes a lip or seat for the hatch to rest on when put back into place. After it is epoxied into place then a small strip of the rubber weather stripping is stuck to the expose lip section I just attached. The hatch will seat/sit on that when in place. Then rig up your straps to hold the deck down and it is done.
If you want to make sure the hatch is held in place ... put three pieces of corner round on each edge or side ( about 1/8th of an inch in from the edge) of the hatch and run your straps over those pieces to cause a downward pressure against the hatch cover. ( it is the way Pygmy Boats tell a person to do it )
I have hatches on my Coho and it has been in some bad rain , both when paddling and when on the top of the vehicle and I have not had a drop of water get in there. Well some did get in when I removed the hatch to get my gear out and it was raining but that came off me as I bent over the opening to get the stuff out.
Personally I like the hatches and bulkheads in the boats , when camping down here the critters can't get to the stuff in the compartments that I call my safe deposit areas. :lol: They can explore the cockpit area all they want.
Without bulkheads in a kayak, you all ready have two holes in your boat that are way bigger than any hatch. They are the area between deck and hull at each end of the cockpit.
Sea kayaks, have evolved to the point where, internationally, any sea kayak without said hatches or bulkheads is not recognized as such - regardless of hull form. The reason for this is safety.
Without bulkheads, it is still possible to keep the laden and swamped boat afloat by using dry bags etc poked up under the deck but they are unable to reduce the volume - or the water holding capacity of a kayak, like bulkheads and hatches can. Any kayak with a cockpit full of water is difficult to keep upright. A kayak with the entire boat full of water - minus the volume of air in your dry bags is impossible. Add to that the equation of all that extra water to pump out.
I like hatches and bulkheads for all of the above reasons and for the ease of loading and unloading my boats. It is possible to construct a strong and attractive hatch that in my opinion, will not only add to the looks of the boat, but also increase its functionality and safety and at the very least, be as strong or stronger than the original deck, without affecting the integrity of the boat.
I like my hatches
But you guys dont talk Jack into liking them it is good entrtainment watching Jack stand on his head looking up under the decks and cussing because it is in the front of the deck.
I own one dry bag and it is carried on top of the back decked strapped down
There aint no perfect tent boat hatch wood are women
Mick, I'm not sure where you ever got that idea, but it is wrong. Cockpit liners present a safer solution than a bulkhead and hatch system.
A kayak without hatches uses a cockpit liner. The boat now has a limited area for water to enter. Accident reports, some with fatalities, are replete with stories of lost hatches, flooded holds, and Cleopatra's needle syndrome.
We're just going to have to agree to disagree about hatches. But, we agree on beer. Only the important issues, ehh?
I have listen to you on this subject a few times and I have a couple legite questions,
Now you tell me what you think about how my boat is set up
Cockpit has sealed bulkhead at both ends
hatch pretty water tight in both ends
8 inches from bow and stern are bulkheads front and back with non water absorbing foam stuffed in them, these are not sealed water tight (flotation)
I can flood everything on my boat and it will not sink,Its just as easy to pump a sealed compartment out as it is to pump out the cockpit, my boat is not going to stand on end.
Paddling with you at Pk you didnt have a liner in your cockpit (Sock)
Your odds of having a leak in a drybag is better than me loosing a hatch,plue if you do loose your drybags in a roll over you have no floatation, I really dont understand your thinking on this ,am I missing something.
Now I can under stand this line of thinking if you are in a SOF you dont have a choice
To my feeble little redneck mind my boat is safer than yours,I have two devices in place for floatation,sealed hatches and positive flotation locked under the deck.
To me a cockpit liner is just a temporary bulkhead and probably not as tough .
On the subject of sealed hatches any presure that builds will just push out past the seals on the hatches
Fill my kayak with water...... Flood it....sink it....do what ever you want and it will bob right back up since there are two ( Watertight ) bulkheads in it and the only part that will have any water is the center cockpit area. YES...My hatches are water tight creating air chambers on each end. Can you say...dry storage for my gear , about 2/3 rds of the boat. :?:
Didnt we all agree that wood dont sink? In the ocean wood oughta float even better in all that salty water. I caint recall watchin' any boat sink....wood 'er plastic. So....ya'll arguin' bout how ta keep gear dry?
Bozone (n.): The substance surrounding stupid people that stops bright ideas from penetrating. The bozone layer, unfortunately, shows little sign of breaking down any time soon.
Now Bear we ain't arguing we just discussing the merrits of different was of doing stuff, I really figure as much hot air as is located here on sparky forum we couldnt never sink ,now we might melt a thing or to.
Truthful Jack wuz gone fer quite a spell 'n Mick aint been on a holiday in weeks, so I figgered somethin' must be up.......the stars jest aint lined up rite. Then them Mexicans cut up one anuther cuz one of 'em farted at the Clarion Motel where I stayed in Waco. I reckon there mite be some wood that sinks, but I figger even my plastic boats will float, no matter how much water ya put in 'em, so I figger this "discussion" must be bout keepin' gear dry? Seems ta me a bag oughta do that az good az a hatch....but I seen yer point that a deck keeps the air frum slowin' yer boat down. If ya got a deck on yer boat, seems ta me a hatch mite make it eazier ta git yer stuff out....if it iz a mitey big one (long 'n wide).
Whew....it wears me out when I git ta elucidatin' on stuff I dont know too much about. I done a heap a elucidatin' after I got my philosophy sheepskin frum Bodine College. If any of ya'll aint been ta college, philosophy iz big time boat science. I hope ya wore them high dollar boots before ya read this one? [chuckle]
certified boat scientist
Make yourself sheep and the wolves will eat you. Benjamin Franklin
Ok,since I started this thread, I'll put in my 2 cents. It seems to me, that if you go to a closed boat (kayak) from an open boat like a canoe or a pirogue, you are mainly interested in keeping water out of your boat. There are other benefits like less wind signature, etc. The goal seems to be to keep out the most water under the greatest range of scenarios. I think the bulkhead / hatch arrangement has to be the best at doing that. Two thirds of your boat sealed to the elements has got to be the best way to go. Just think of the untimate floating paddling/fishing platform- the SOT kayak. It's a sealed hull with a place for the paddler to sit- same concept as a kayak with bulkheads.
As far as the strength of an intact deck as opposed to one with a hatch - hardly a consideration in a well built boat.
As far as this Cleopatra's needle, I think it would be MUCH more likely in a boat without bulkheads.
Take this opinion with a grain of sand from a non-epoxy, non- glass , open pirogue building Cajun. :mrgreen: