Not going to be a problem at all. The thermal expansion problem can be taken care of by drilling a small (2mm) hole in the top of the bulkheads. 
 

George K.

It's an excellent idea to take your boat out for a period of sea trials before finalizing it. Not only is it a lot of fun, but just think of how terrible it would be to have to either change something after you've done all the sanding, varnishing and painting, or to have to use your boat when it's not exactly the way you want it.

As far as the hatch choices go, on my wife's 16LT I left off the front hatch entirely. After 15 years of using the boat, she's never missed it and still prefers the look of the unsullied front deck. It also provides a lot of uncompromised buoyancy in the bow. She never has to worry about a wave removing a poorly fastened hatch cover and swamping the hatch space.

The rear hatch is a standard one, but over the years she's come to wish that it was a flush mount, mostly provoked by seeing me paddle alongside in my WD12 with the flush hatch cover. The good news is that she spends most of her time looking forward and only seeing her hatch-less deck.

So my suggestion is, unless you're going to be hauling a lot of cargo, go hatch-less in the front. As George pointed out you can just drill a small hole to equalize the pressures if you want. (FWIW, I didn't and it's gone 15 years without exploding, probably because I sealed it in the summer so it's not full of dense winter air.)

Have fun.

Laszlo

Please excuse my ignorance, but I am still in the planning stages of my first build.

So, if you don't have a hatch, how do you access the interior joint of the deck-to-hull? Don't you need access to apply the fillets and pour the epoxy into the bow and stern?

Rob

Rob,

If you're doing end pours, do them before attaching the deck. For boats with sheer clamps, the deck is glued and nailed to the sheer clamps, so you won't be applying fillets between the deck and hull.

For boats without sheer clamps, you use tools on the end of long sticks to make the fillets and to apply the glass tape.

Laszlo

Laszlo--

I am trying to picture in my mind assembling a Shearwater 16. I like the idea of a clean deck. I have already received the Assembly Manual and read it a few times, then a few more times. If you happen to have one in your back pocket you can read along with me on page 39, "The only way to get by without hatches is to remove the interior bulkheads and glue the interior hull-to-deck joint by reaching in from the cockpit." It goes on to point out there are drawbacks in hull strength and safety without the bulkheads.

I am wondering if I could cut temporary hatches in the bulkheads, do the assembly, then seal the bulkhead hatches. These "hatches" would only be visible to those craning their necks into the cockpit. I could put a small hole in the top of each bulkhead and stick a cork in it. The cork would provide a water resistant seal, but be removed for drying and travel to and from mountain lakes.

My kayak trips are only one day. Most of my kayaking will be on lakes, but I will occasionally venture onto rivers and protected ocean bays.

Your thoughts?

Thank you, Rob

this is a good thread and i thought i would add a couple of perspectives from my experience having built several chesapeakes as well as the shearwater line and a handful of strip-built boats and being an avid kayaker for the last 20 years 

first, my opinion on hatches.  i like forward and rear hatches.   they are practical for a number of reasons:  1) they provide convenient access to storage, 2) the provide access to otherwise closed areas to effect repair and help ensure the space inside is as expected (dry).  3) even if you don't use them often, the problem without them is you can't make them happen on the fly.   4)  they also impact your construction approach... so in their absence, you need to think very carefully about how to change the build order, engineer for the appropriate stength in their absence,  or deal with a place you will never see the inside of.

second, the relationship between hatches and bulkheads:      if you have or want bulkheads, i think you should have a hatch.  i think for reasons above, deck hatches are the most convenient.  but closed areas, in my view, are a no-no.  i just am not comfortable not being able to inspect a hull i am relying on.   waiting to see a problem from the outside or hearing water slosh around where it shoudn't,  in my view is simply too late.  with respect to sea kayaks, i also want bulkheads to minimize the amount of water that can be taken on if you swamp or have a failed role.  bulkheads are also important structural elements and you have to change the build/layup to add strength in the absence of bulkheads.  the only kayaks you routinely see without fore or aft hatches are racing boats and whitewater kayaks or very short boats that don't need bulkheads for strength.

third, can a boat look good with a hatch?  opinions may differ, but i think you can have a very good looking boat with a hatch and i have some kayaks where the hatch are flush and some that sit up on top...and some approaches that attach the hatch with toggles, some that use straps and some that are blind (attached with rigging from the inside).  so its really never been an issue and is part of the whole deck layout and the look i am trying to get.  so i can get a look that is very much like no hatches (flush and blind) if i want....its just a bit of effort.  

can i build a boat without the hatches and add them afterwards:  the chesapeake line has the hatches happen towards the end and you can, if you want, take it out for a spin before adding hatches.  shearwaters typically set up their hatches prior to the deck and hull being attached becuase they want you to have access to do the inside taping through the hatches becuase they assume you will have bulkheads.   also, the hatch structure of a shearwater would be challenging to do blind...but doable.    generally i follow assembly order becuase its been worked out what the issues are....and going out of order means you have to do a lot of thinking to ensure you did not put yourself into a corner that you did not anticipate.   interestingly , in most strip builts, becuase the decks are not tortured (bent over the bulkhead), bulkeads often go last after the hull and deck have been taped.   a shearwater, unlike a chesapeake, can do bulkheads last as well as the deck really does not rely on the bulkhead for shape...just strength.   but then it makes it a pain to put the bulkhead in after the hull and deck are together.

if i put a pin hole in the bulkhead, where would i put it?  in the discussion above, its mentioned putting a small hole in the bulkhead to allow air to equalize.  in my experience, this is a very good idea.  it can get amazingly challenging to get a hatch off if there is no pressure equalization.   however, i would put the hole in the middle of the bulkead (not at the top).  the reason i suggest the middle is it allows the boat to be up to 1/2 full before any water would get in. when you take on water in a cockpit, however, remember that the boat is not always right side up....it might be upside down.  so the middle of the bulkead is where i was always told by wise folks where to put it.

can you do an endpour without a hatch?   endpours can always be predone before the hull and deck are attached if you put some material up in the ends and simply make it part of the assembly process.  i typically do this to keep a boat light.    however, if you really want to 'pour' your end pour....then you have to have access.

anyway, i hope this helps.  lots of ways to skin a cat at this.   hatch fan:)

h

I was busy typing a long and detailed reply to this thread when I saw that Howard beat me to it with his excellent post.  I only have a couple of things to add:

First, another reason that I am big on hatches is so that you can clean and dry the interior spaces.  Somehow, someway water eventually gets in there.  It is as unavoidable as taxes.  If it is salt water, the salt stays there even after the water evaportes.  Overtime, the salt accumulation grows.  Since salt is hygroscopic, it actually holds water so the compartment never drys.  This is a huge problems with older surfskis which frequently weigh several pounds more than when they were new.

My second point is that it is very hard to properly tape the interior hull deck seam on long kayaks without hatches.  Taping the seam through the cockpit is easy enough on a boat like a Wood Duck because it is short and has a large cockpit.  As the boat gets longer, this technique get progresively harder.  Consider that on the Mystery, the bow extends over 8.5' forward of the front of the cockpit cut out.  I have both forward and aft hatches on that boat, and it was still a huge PITA

If

If you do not like the look of hatches, I would recommend use of CLC's flush hatch kit.  If you are careful, you can use the cut out as the hatch cover so the wood gram matches.  They also sell an invisible hold down kit which eliminates the toggles.

Laszlo, Howard, Mark--

I really appreciate all your thoughts and inputs. After these comments there is no doubt I will follow the directions to the letter - no deviation. The instructions are written that way for a reason. Thank you to you three, and all the others that have chimed in on other points.

Dan, I hope I did not hijack your thread too far afield.

Rob

Thanks everyone for your replies and discussion, it's much appreciated. I'll add a couple of holes to the bulkheads to be safe, likely towards the middle of the bulkhead to avoid any water entering in the event that I don't stay as upright as planned... I'm leaning more towards the flush hatch option so I'll have my work cut out for me (pun intended) over the New Year finishing that off.

And Rob, no harm done! I thoroughly enjoy reading everyone's experiences and advice on all aspects of boat building.