Step 18: Cut Deck Beam 5

Deck beam 5 is our other curved deck beam. To figure out how much elevation it needs, we lay a short piece of straight wood across deck beams 4 and 6 and measure how high the stick is above the tops of the gunwales at deck beam position 5.

If you have big feet and want extra toe room, lay the stick across deck beams 3 and 6. This will give you even more elevation. You will later add deck stringers to stretch from deck beams 4 to 6 or from 3 to 6 and this is what this stick simulates.
<p>I may have wound the ropes that loop around the gunwales at the bow and stern a little too tightly because my gunwales sure do flex a lot more than what I'm seeing in the pictures. Unfortunately, I didn't recognize this until after I cut all the deck beams. Sure hope it doesn't spring apart later. I'm having a blast building the kayak so far - so thanks for the instructions!! Sure beats doing laundry or mowing the yard (though now my clothes stink and my yard is embarrassing).</p>
<p>Do I use Glue at this time for the deck beams and dowels?</p>
No glue needed. The joints are backed up by lashings. The boat is less likely to break if it is allowed some movement.
<p>Just wondering why the single lashin? Why not a &quot;Y&quot; lashing to the gunnwal?</p>
I guess the single lashing is adequate. Mostly, you don't want the boat to fall apart with the skin off. Once the skin is on, it holds the gunwales against the deck beams pretty well. <br>No harm in the y lashing, I suppose. Probably makes for a little stiffer boat which might be good or bad depending on whether you want a stiffer boat or not.
It's interesting: I built a kayak frame (haven't skinned it yet) from some leftover cedar I had from another project (fixing the front porch), and I used very similar techniques to what this guide shows.
@ ihanutdyv: Cunningham also mentions dowels for the deck beams. I have built several kayaks, all doweled. All are strong enough to survive repeated pounding in 6' surf with no ill affects.
In his book Chris Cunningham make mortises for the deck beams. It seems like you are not. How much strength do you think is lost by doing this? Thanks for the instructions!
What wood do you recommend for the deck beams? I have left over spruce from the gunwales that I'd like to use, but it looks like you used some kind of hardwood. If I use hardwood, will it bond nicely with the spruce?
go ahead and use the spruce. I use whatever is laying around. I don't usually use hardwood for deckbeams to keep the weight down.
thanks for your update, and for all the effort you put in to the reply. im afraid that im a very visual learner and im trying to find a video that shows the whole process i have seen some efforts done on youtube of some of the build but not enough detail, and mostly by amater builders or filming that does not show how it is done. i wish your work was on video as it is the best i have seen so far. i think it would be a God send to complet woodworking none kayakers like be. thanks for your help the info will be good when i get to that stage of the build cheers john. ps if you know of any building videos let me know. all the best john.
sorry for the slow response. for a video, see the bibliography on my web site http://wolfgangbrinck.com/boats/bibliography/kayak.html Build Your Own Sea Kayak!, Robert Boucher. Milwaukee Wisconsin, 1993. I don't know if these are still available, but worth looking for.
So, when viewed from the bow direction, the spreader should have a trapezoidal shape?
Yes, that's right.
hi all. does anyone know where the info is about the cockpit for the greenland thanks for any help. this is my first project so i need as much help as possible. i would be greatful for any advice that you think would help me in anyway. thanks all
It's been at least a year since I wrote this instructable. So I don't know if I plain forgot instructions for how to bend the cockpit coaming or not. In any case, here is a short summary of how that's done. To make a coaming, cut a piece of hardwood like white oak 1-1/2 inches wide by 1/4 inch thick and 8 foot long. Soak it in water for 3 days to a week. White oak is hard and bends well, but you have to find a piece with good straight grain that runs parallel to the edges of the coaming. Poplar also works and has negligible grain and so is easier to find with suitable grain but is not quite as strong. Cut another piece of hardwood the same length as the first one, 3/8 inches thick by 1/2 inch wide. This will be the lip of the coaming. While the blank is soaking, make a bending form for the coaming out of a piece of plywood 5/8 inch or 3/4 inch thick. Your coaming should be roughly egg shaped or elliptical. your back will be against the flat part of the coaming. Length should be about 22 inches or whatever the distance is between the deck beams on either side of the cockpit. Width should be at least 16 inches. Draw out the shape of the coaming on the plywood and cut it out with a jigsaw. Then draw another ellipse inside the elliptical piece of plywood you now have to give you something that looks like a toilet seat. Cut out the hole in the center. The rim should be about 2-1/2 inches wide. The reason for the 2-1/2 inch dimension is that it allows you to clamp the coaming wood t o the bending form with 3 inch clamps. When the bending form is done, find my instructable on how to make a steam box. If that looks like too much work, you can bend the coaming using hot water. When the coaming wood is done soaking, pull it out of the water. Make a mark on the face of the coaming form near its outer edge. Line the mark up with the end of your coaming wood and roll the form on the coaming wood until the mark comes around one full revolution of the form. You now know how much wood you need to wrap around the form. Make a mark on the coaming wood. Add another 8 inches for overlap and make a mark there. Double check your work to make sure your piece of wood will wrap completely around the coaming form with 8 inches extra. When you are sure you measured correctly, cut your coaming wood off at the right length. Since you have 8 inches of overlap, you will want to taper the two ends with a plane so you don't have a step at the edge of the lap. Do the same thing with the thinner strip of wood except cut it 1-1/2 inches longer than the coaming piece. If you use a steam box, bring the coaming up to temperature, maybe ten minutes then pull it out of the box wearing gloves. Clamp one end of the wood to the form so the 8 inch lap is centered at the back of the form. Then wrap the wood around the form and add clamps as need be. It is good to have some help at this point. One person holds on to the wood while the other puts on clamps. If you have a wooden work surface, after you get the first clamp on, the easiest way to bend the coaming is to roll the form over the coaming wood with the coaming against the surface of the table. Work fast since the wood loses heat quickly and stiffens up. You should be able to get the wood bent around the form and clamped in under a minute. If you have gaps that bother you, you can play with the clamps and get the coaming to fit more tightly. Repeat this whole procedure with the narrow strip of wood. Clamp it to the outside upper edge of the coaming to form a lip. This lip will hold on the spray skirt. Let the coaming and the lip dry on the bending form for at least 24 hours to let it dry out. When dry remove it from the form while keeping it clamped. Secure the ends using waterproof glue, copper rivets, ring nails or whatever suits your fancy. If you don't like steaming, you can bend the coaming a section at a time using boiling water to heat the wood. Clamp one end of the coaming wood to the form, then ladle hot water over a six inch section of wood for a few minutes. Bend that section around the form and clamp it, then move on to the next section. If you have enough clamps, you can do the coaming and the coaming lip right in succession. If not, you may have to
&nbsp;Thanks for the great instructable! &nbsp;Do you use wood glue in your dowels? &nbsp;Thanks!
No, the dowels are a press fit.&nbsp; Some movement is allowed<br />
Great Instructable. Thank You. I am up to step "8", and, having neglected to check my gunwales for matched flex, I am now going crazy trying to fit the end spreaders in between two gunwales with unmatched flex; everything looks warped, like a big plantain, once I wedge them in and (try to) even up the ends, bow and stern. So is there a "fix" at this point, or is it best to chuck the gunwales and start over?
would it be fine to make raised deck beams behind the seat also for more storage?
Yes. Just keep in mind that changing a working design has consequences. Possible negative consequences of raising the rear deck: Makes the boat harder to roll. not a problem if you don't intend to roll. Might impact susceptibility of the boat to wind. The back of a Greenland kayak already has a tendency to go downwind. You can offset that problem with a skeg. You might have to increase the size of the cockpit because a flatter coaming is harder to get into. etc. etc. On the plus side, If something on a skinboat doesn't work, it's easy to change. In this way, skinboats are much better than just about any other kind of boat. Or you just build another boat that incorporates what you learned from the first boat. Building time for a skin boat is relatively short.
On the first picture of step 15 it looks like the gunwales look like they would form a v shape, is this just exaggerated so that its easier to see?
The flare of the gunwales for this particular kayak is around 25 degrees off the vertical. The angle in the drawing might exaggerated slightly.
On step 23 what is the measurement from the bottom edge of both of the gunwales? The number is fubar in the instructions.
It's 3/4 inches.
This question comes from someone who's "building" experience is assembling Ikea furniture... Screws versus dowels (& lashings) - it seems that the dowels & lashings give the kayak a more traditional feel. But, I wonder if construction could be simplified by the use of modern day deck or bronze screws?
As soon as native builders could lay their hands on them, they started using galvanized nails for joining ribs to stringers. Mostly as a time saving measure, I imagine. Gunwale to deck beam joints using screws might be OK too. Feel free to experiment. The two possible downsides to screws would be loss of flexibility, requiring more heavily dimensioned parts to give equal strength and cost of corrosion resistant hardware.
great! cant wait still step 4!

About This Instructable




Bio: skin on frame kayak builder since 1987
More by nativewater:How to renovate your old hammer How to hit the road on the cheap Build a Greenland kayak part 6 
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