One more cycle of fill and sand, and the fairing should be done.

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I built a ten foot diameter yurt suitable for camping.  The ten foot diameter seemed suitably large for comfort but not so large as to provide a transportation problem and also not so large as to overflow available camping spots. Our intent was to give it a good workout in Kings Canyon National Park.  By and large, it worked out with minor problems.  Pictures and comment below.

This shot was meant to show how small the yurt looks in a natural setting.  It looked much larger when I first set it up in the driveway of our house. We left the roof cover off so we could look at the stars at night.

Here is a picture of the yurt in the afternoon when the sun is hitting it.  We peeled back the wall for better air circulation.

Here is the yurt with the roof cover on.  We may still sew darts into the overhanging portion of the roof to take up the wrinkles.

After we got kicked out of Kings Canyon due to government shutdown, we found a camping spot in Sequoia National Forest right next to a Jeffrey pine.

Here is a longer shot of the yurt to show its size in proportion to the pines.

And then it snowed.  Clouds moved in in the morning and we put the roof cover on.  I had not yet made a smoke hole cover so a plastic tarp had to do the job.  The snow all melted once the sun came out.

A closeup on the tension band that holds the top of the wall in against the pressure of the roof poles.

And a closeup of the roof pole to wall junction.

The tarp leaked a little since laid flat over the smokehole ring to which I had not yet added any arch.  Here I have added some willow twigs to remedy that problem.

All in all, we were pretty happy with how the yurt behaved.  Next addition, some flooring to isolate the bedding from the ground and a small wood stove for heat.

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The side planking is all on now. So, the next step is to cover the transom with Meranti so that it will match the deck.

First, I made a posterboard template of the transom. Then I positioned the template over an attractive grain pattern on the Meranti plywood. I traced the template, then drew a secondary line extended 3/4” outward from the tracing. I cut to this secondary line so that my transom cover would be oversized sufficiently for me to fit and position it as needed.

Posterboard template & oversized transom cover.

The next step will be to attach it.

To help with this, I have ordered a Raptor stapler and some 9/16” Raptor staples. The Raptor staples are plastic. So, you can simply sand off the extraneous end of the staple once the stapled piece of wood is bonded to the sub-layer. This should leave little or no evidence of fasteners, as would be the case with screw heads, etc.

That’s the idea, anyway. The stapler should be here early this week. I’m looking forward to trying it out.

 Side planking trimmed at the bow.

Side planking trimmed at the bow.

 

Fairing progress on the side planking.

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A woman who will be building a kayak with me gave me a tour of her housboat community in Sausalito.  I took some photos of the houseboats and a few of the rowboats docked near the houseboats.  The nice thing about a rowboat next to a houseboat is that in the morning you can get some exercise without going to the gym.
Not much to comment about here other than that the houseboat community seems to have arisen sometime in the 60s.  Some notable folks have lived on housboats in Sausalito, among them, Alan Watts, a popularizer of Asian religions and more recently, Steward Brand, publisher of the Whole Earth Catalog.  All these names used to be household words back in the seventies.  More recent arrivals to this world may have to google them.  So without further ado, photos of houseboats --
One more thing.  I should mention that there are several groupings of houseboats in Sausalito and this is just one of them.

Some housboats are boats.  This one used to be the Mare Island ferry.

Some houseboats like this one have floats.

The quonset hut.

And this one would be at home in town with a lawn out front.

And this one looks like a tugboat expansion

And some rowboats

This is a model that students build in a class.  Each student gets to take home their model.  And all students also work on the full size boat pictured below.  I assume they get a ride in it when its done.

This pram was just sitting there at a boatshop.

 

The boats above are famous designs whose names I was told but promptly forgot. But to my credit, I recognized the names. You would probably as well.

This one just looked bright and cheerful.

And one more cheerful set and then we have to go.

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Ben, my neighbor at the shop is building a motor boat. The process of boat building is a great deal easier than it used to be due to CAD files and NC routers. The long and the short of it is that you no longer need drawings from which to build a boat.  The shape of the boat parts is contained in a file that can be downloaded to a numerically controlled (NC) router that cuts not only the molds but also the frames and bulkheads that make up the boat.  Once all the molds are routed out, they are assembled in a manner that resembles one of these stegosaurus models they sell in museum gift shops.

 Once you have all the molds and frames assembled, you are ready to glue the permanent components together.  After that, you cover the whole thing in plywood and then in fiberglass and epoxy resin and you have yourself a boat.  No lofting and other traditional unpleasantness.

The view from the rear.  Note the cramped quarters.  Luckily, Ben has all of his machinery on wheels so he can roll it out of the way or into position as need be.

Three quarters view from the rear.  The plywood stays in the boat and the stuff without grain is temporary molds and gets removed.

The view from the front of the stegosaurus.

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After three sessions, the hull now is completely covered with 6 oz glass.  I still need to squeegee on two more coats of epoxy and then some sandable filler to smooth out with the long board.  But, pleased with the progress.  i will need to wash the epoxy blush off prior to filling the weave as the port side has sat for over a week and has some evidence of blush.

transom recieves its glass.  Light spots are filler to fair the tape at the seams. 

Christos was here!

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One more time now. Back to the topic of what makes baidarkas flexible and why one would make a baidarka flexible. This I hope to be a definitive treatment of the topic, by me anyway. 
I touched on this in a previous post prompted by a visit to the Phoebe Hearst Museum of Anthropology at the University of California in Berkeley. What I discovered on that visit were a bunch of modification to the Atkan Iqyax^ in the museum collection, apparently made to reduce the flexibility of its frame.
There are some accounts on the topic of flexibility that indicate that the Unangan builders tuned the flexibility of their iqyan to suit conditions.  High flex iqyan were built for rough water conditions and low flex iqyan were built for smooth water conditions.  The flex of any given iqyax^ couldnt be modified on the fly but as the frame in the Hearst museum indicates, flex of a flexible iqyax^ could be reduced by modifications to the frame when the skin was off.
On a related note, Father Veniaminov commissioned the building of an iqyax^ with bone shims in Unalaska roughly 200 years ago when there were still people who knew how to build such boats.  His informants told him that the shims increased the speed of the boats. When he tested the iqyax^ with the shims, he found that it was no faster than an iqyax^ lacking the shims. But even though the test was inconclusive, it may be that he tested the boat only in smooth water conditions where the shims would offer no advantage.  In addition, we do not know if his builders tuned the flex of the commissioned iqyax^ to take advantage of the shims.
So without further ado, on to the details of how to tune the flex of an iqyax. Let us start with a picture.

The picture shows two aspects of the iqyax^ frame.  The top frame is shown in roughly neutral position such as the iqyax^ would assume on flat water.  The bottom frame is shown in flexed position with the ends pushed up such as it might look at the bottom of a wave trough.  Not shown is the frame with the ends flexed down, a configuration the frame would assume when going over the crest of a wave.
The important thing to note is that the keelson is slightly curved in the relaxed position. Flexing the keelson more as in the bottom picture would move the tail fin and bow assembly closer together, closing their respective gaps between them and the deck end cross blocks. Likewise, if the ends of the frame flexed down, the keelson would straighten out and the tail fin and bow assembly would move away from the deck, increasing the size of the gaps.
The question for the builder is how to tune the flex.  Should the kayak in the neutral, unstressed position have gaps at the tail fin and bow assembly or should they be tight up against the deck cross blocks?  My guess is that for optimum flex, there should be about a half inch gap both at the tail fin and bow assembly in the neutral position.  This allows flexing of the keelson upward and downward.
If there is no gap in the neutral position and the ends of the keelson flex upward, the keelson would exert pressure on the ribs and flatten them, thus distorting the hull.  If the gap is there, the keelson ends can flex up and close the gaps without distorting the ribs. 
The parts of the frame are joined in such a fashion that the keelson, the bow assembly and the tail fin are all lashed or pegged together tightly so that they act as a single unit. That is, the parts of this assembly do not move with respect to one another.  The keelson is lashed to the ribs, however, the ribs are loosely set into their mortises so they can pivot forward or backward as the keelson flexes.  Also, the tail fin is slotted into the back of the rear cross block but is free to move forward or backward.  Likewise, the rear deck stringer is not lashed to the tail fin to allow it freedom to move forward and backward.
At the bow, the bow assembly joins the deck.  The deck plate joins up with the ends of the gunwales but like the tail fin, can move forward or backward, opening up a gap in the process.

 

The picture shows the gap between the end of the deck on the left and the bow plate on the right.  The deck stringer has been lashed to the bow assembly, a modification to limit the motion of the bow assembly away from the end of the deck.

The notch in the tail fin mates up with the tail cross block.  The lashings between the tail fin and the cross block are an add-on and limit the ability of the tail fin to move forward and backward.

 

This picture shows one of the two lashings that join the tail fin to the keelson.  This joint is quite rigid so that the tail fin would move with the keelson rather than sliding back and forth on the keelson.
So to recap, to build a flexible iqyax^ the key is to allow the tail fin and the bow assembly to move closer to or away from the ends of the deck as the keelson shortens as it is flexed or lengthens as it is straightened.
To allow internal movement of the frame also requires the cooperation of the skin.  If the ends of the kayak are to move in and out, the skin must have enough stretch to allow this motion.
Modern synthetic skins may or may not have enough stretch to allow motion of the frame.  Also painting the synthetic skin with a sealer that penetrates the skin tends to glue the skin to the frame, essentially preventing internal motion of the frame and cancelling any structural allowances for frame motion.

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