Marcuse,

The endpour ties together the pieces of the bow. It's not just an anchor for the handles. It provides stiffness and strength in exactly the same way that a traditional stempiece does, especially in the event of a direct head-on impact at speed.

Endpours can be skipped as long as alternate arrangements are made to provide the strength and stiffness and to anchor the handle. The best alternative is a wooden stempiece bedded in epoxy/woodflour putty inside the bow. Depending on the type of wood, it can be stronger, lighter and cheaper (and a lot less trouble) than an endpour, but it has to be done before the deck is attached.

Another alternative is to build up an external stempiece from multiple layers of glass/epoxy. In that case, the glass should extend several inches behind the bow on each side. Each layer should be shorter lengthwise than the previous one so you will have a smooth (or more easily smoothable) taper. The heaviest layers at the bow will obscure the wood grain and be obvious, so this would work best for a painted hull. It also doesn't do anything for anchoring the handle, so something like the arrangement you describe would be necessary.

There's also a compromise of a wooden false stempiece covering the thickest part of the glass. Again, this would need your alternative method of anchoring the handle.

Personally, I've always preferred the internal stempiece. It's easier to install and doesn't need to be elaborately shaped and beveled since it ends up totally hidden.

Good luck,

Laszlo

Hi Marcuse, 

i wanted to also reply to your note and give another perspective.

i am of the opinion that the main purpose of the end-pour is to create  a solid block in the bow-stern through which you could drill a hole for a rope/grab loop, such that the hole would not open up into the hull letting water in..

while it may have additional structural value to 'tie together the pieces of the bow'  it goes well beyond what in internal stem piece does.

for the specific boat, a CLC 17, if you have properly filleted inside the bow area and put cloth on those fillets (just like you did on all the seams where the hull sides and bottom join, you have plenty of strength.  once the deck is in place adn you have glassed the boat, you now have a triangle wrapped in glass .....and this is an amazingly strong structure absent the end-pour.

while i mention that this is an 'opinion' i say that becuase i do not have scientific test resuts to show you.  however, i do have a substantial number of builds (20 kayaks and counting including four CLC 17s) and have done a lot of experimentation in this space.  but i have never had a stitch or strip build suffer a failure for lack of strength in the bow area resulting from not putting an end-pour in.

that said, i have not routinely lauched a boat off the roof of my car or attempted to harpoon a rock.  i have had the first four inches of a shearwater broken off once after the bow got stuck in a dock and the boat got pushed sideways and it broke off the bow just after the end-pour.....but that was like a 10 foot lever arm on the bow as if the bow was in a vice.... kind of situation.  i suspect that i still would have broken off the bow in that situation had i completly filled the boat with epoxy.

i have also routinely done the minor crashes and bangs...so while i try to treat my boats kindly....i do use them a lot.....and both boats with/without endpours have easily survived these more minor abuses.

so in summary, in my view, if you have an alternate mechanism for handling the boat, if its anchored properly, you can dispense with the end-pour and the weight penalty.

h

Howard,

FYI the reason your boat broke where it did is because the endpour termination acted as a stress concentrator. If it had been tapered instead of just ending abruptly at the very least the location of the break would have moved, but it might not have broken off at all, just crushed. That's why when I build a carbon fiber mast with internal reinforcements I taper them to a 45 degree or shallower angle. For the masts it's the difference between breaking or surviving.

Laszlo

thanks lazlo,

i think in summ, the only point i was trying to make is that, in my experience and thinking through the matter,  end pours typically are not going to make a signifcant difference in a stitch and glue boats durability....and so you can safely consider saving the weight if its important to you to do so.  the CLC 17, absent an endpour, is not something  i would consider delicate or in need of special handling.

as you mention in your example of carbon fibre mast (which is not filled with solid epoxy) there are a lot of approaches to making something durable....and, of course, there are different kinds of durability depending on the 'abuse' case you come up with.  

while i don't agree with you that had my construction been different, i could have avoided breaking the bow off, that's probably more about my ability to describe accurately a relatively freak incident (once in a 30 year+ paddling career) kind of thing that probably would have broken the bow off of any pointy ended kayak regardless of construction.

the nice thing i suspect we could all agree on is, unlike a commercial kayak,  i was able to repair it in a couple day and you had to look pretty hard to notice that there was a repair:)

h

>>while i don't agree with you that had my construction been different, i could have avoided breaking the bow off, that's probably more about my ability to describe accurately a relatively freak incident (once in a 30 year+ paddling career) kind of thing that probably would have broken the bow off of any pointy ended kayak regardless of construction. 

Or my ability to visualize the situation when I wasn't there.

Definitely agree on the homebuilt repair advantage.

Laszlo