Jumat, 22 Juli 2016

The Raptor stapler I ordered came in yesterday. I took it home and put it right to work.

Raptor CT-6000P Compression Stapler
Raptor CT-6000P compression stapler
The model I’d ordered is the CT-6000P. It is a manual compression stapler, not one of the fancy air-powered tools. However, I didnt have to handle this stapler long before I got the impression that it is better made than similar tools Ive seen at big-box stores. That’s reassuring, given that the CT-6000P isn’t exactly cheap.

It is made specifically to use the proprietary Raptor composite staples. Those aren’t exactly cheap, either. The tool, a box of 9/16” staples, and shipping totaled a little over $125.00. Question is... is it worth it?

So far, I think so.

The first thing I did, of course, was to try the stapler out on the closest object available. I tried to drive a staple through a sheet of 1/4” eucaboard on a work table into the 3/4” plywood table top. That didn’t go so well. Not only did it not penetrate the eucaboard well, it sent shattered pieces of plastic staple flying everywhere. The second shot didn’t fare much better. I crossed my fingers and hoped that 1/4” Meranti plywood would be a different story.

It was.

I tried the stapler out on several pieces of scrap plywood, adjusting the tool’s set screw a little as I went along. It worked very well, easily tacking Meranti scraps together, as well as into a piece of 3/4” pine plywood. The 9/16” staples did not seat fully, but sufficiently enough to hold two layers of plywood together long enough for the epoxy between them to cure. That’s all it needs to do. In fact, a little bit of extraneous staple remaining above the wood surface should make it easier to break off & sand away. That’s the whole point of using composite staples in this project: to leave little or no visual evidence of fasteners.

So, confident in the knowledge that it was going to work, I decided to go ahead start mixing epoxy. In the end, I had to mix 3 batches. It took far more epoxy to cover the surface area of the transom, as well as the mating surface area of the transom cover, than I’d estimated. Once again, the kitchen scale was indispensable in this process. I took the advice of another builder, and enclosed the scale in a large freezer bag to protect it from epoxy drippings.



With both mating surfaces covered, it was a relatively simple matter to clamp the transom cover into position. The Raptor stapler did its job nicely, tacking the 1/4” Meranti plywood onto the 3/4” Douglas Fir plywood beneath it. For safe measure, I added clamps all the way around. 

The transom cover... glued, stapled and clamped.

The next step will be to shear off and sand away the composite staples.

19 gauge, 9/16" Raptor composite staple.

Top of the staple snipped off...

...and sanded away.

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Selasa, 19 Juli 2016

In the previous post we looked at cutting and installing all the deck beams.  I chose to temporarily nail them in place.  While the method I chose is not traditional for this type of boat, it works well enough and is quick.  The Eastern Arctic method is one of digging shallow divots in the sides of the gunwales and pointing the ends of the deck beams to fit into the divots. See the Zimmerly Sea Kayaker Article for details on how this works. The main advantage of this approach is that if you dont have steel tools, it is an easier way to do the joinery since it doesnt require as much precise cutting.  The lashing which comes next holds the ends of the deck beams in their divots.  This method was also apparently used in Greenland until contact with whalers made steel available to them.  East Greenlanders also used the divot method.
The following photos show some details of my hybrid approach of doweled deck beams and traditional running lashing. Doing lashings like everything else in kayak constructions can be done in a number of different ways.  Aside from the lashing patterns themselves there is also the local vs. the running lashing approach.  Running lashings seem to be favored where the lashing material is rawhide.  Where string was available, lashings were more likely to be tied off at each joint.  Another factor in the decision of which way to go was the strength of the lashing material.  Weaker string would take multiple turns at each joint which favors tying off the string.  Running lashings favor a stronger binding medium like rawhide since a break of the lashing anywhere along its length would make the whole run unravel. 
This lashing runs left to right.  The string goes into a hole in the gunwales under the deckbeam to the outside of the gunwale.  Then it goes up in another hole in the gunwale and exits at the top of the gunwale.  Next it goes through the deck beam, loops around the string coming in at the left and heads off on the right.
This shot shows the lashing moving from deck beam to deck beam. The lashing material is tarred seine twine a little under an eighth of an inch in diameter running through 3/16th inch holes.  The tarred seine twine is stiff enough so that it can be pushed through the holes without the need to additional tools.
A view from the outside showing both the dowels and the lashing coming out of the gunwale at the bottom and then heading right in again above.  Note that one of the downsides of dowels and this lashing scheme is that you have to be careful not to drill through the dowels when making the lashing holes.

A view of the lashings from below the deck beam.  The lashing makes its way through the gunwales and comes back again, taking off to the right after looping around its incoming arm from the left.
And finally, a side view of the arrangement.  Note that the deck beams sits about 3/4 of an inch below the top of the gunwale.

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Last night, I attached the blocking that will support the sides of the forward thwart. I used the same procedure as I did for the rear thwart, with one exception: This time, I taped waxed paper to the ends of the seat in order to keep from gluing the seat down just yet. Last time, I used the blue painters tape. 

Waxed paper works much, much better.


2 bar clamps hold the level to the plywood, keeping it straight; 4 bar clamps hold the plywood to the center support; four 4-1/2" deep C clamps hold the 2 pieces of blocking in place against the underside of the seat & the sides of the hull; 2 bar clamps reversed as spreader bars push the blocking against the sides of the hull.


The waxed paper made it MUCH easier to remove the seat once the epoxy had cured, and left no mess to clean up or sand off.

Due to the variety of angled lines inside the boat, the seat blocking appears to angle downward. However, I checked, and they are indeed parallel to the keel.

Angle measurement on the rear thwart.

Angle measurement at the aft end of the keel.

Angle measurement at midship on the keel.

Angle measurement on the center support for the front seat...

...and finally, the angle measurement on the forward seat blocking. Thats consistent enough for me.

Heres the topside view of the forward chine that I had to add more material to 2 years ago. (I cant believe it has been that long ago!)

Next, before I begin encapsulating the inside of the hull, I plan to add false battens to the outermost sections of the floor, just to keep from standing directly on the plywood.


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Sabtu, 16 Juli 2016

I havent done much boat building lately since I have been busy working on a yurt.  Though this blog is supposed to be all about skin on frame boats, I thought it would be OK to indulge in some related skin on frame construction, namely, the yurt or portable dwelling.
The idea of building a yurt came to me after last years October camping trip.  We were pretty far south but at high elevation and so we encountered snow and cold nights at times.  We had an adequate tent and warm sleeping bags but the sun went down early each day and then stayed away for twelve hours so that once it got dark there was little to do but crawl into the bags and listen to books on our mp3 players.  Camp fires and eating are usually good camping entertainments, but most campsites have fire rings that keep the heat of the fire away from the camper and otherwise hamper what should be a good entertainment.  Likewise, cooking food when it is near freezing is possible but once the food is done, it gets cold in a hurry and then you have to clean up in the dark and cold.
So the idea of a tent that was big enough to stand up in and build a fire or set up a camp stove in and cook in and eat in, all in comfort and warmth wormed its way into my consciousness.  The idea of a tipi came to mind, but those require long poles and a lot of canvas and would add a lot of bulk to an already bulky camping load. So then I thought about yurts.  And as a little research showed, there were lots of articles on the topic on the internet. 
In addition, my neighbor, Tim Anderson had built a yurt and so I could use him as a technical adviser.  So off I went on the yurt adventure.  I quickly found out when doing the research that everyone builds yurts their own way and nobody seems to tell you much about general principles like how strong to make the walls or what the pitch of the roof should be, whether the thing will hold up to a snow load, heavy winds and so on.  And so I decided to build a prototype yurt that could sit behind the shop.  I would use it to work out the design details and once that was done, I would build a smaller more portable and lightweight yurt for camping.
So here goes with the photos.

 The target diameter of the yurt is 16 feet so I needed to construct 48 feet of wall.  Circumference of a circles is pi times diameter of the circle, remember?

Heres a closer up view of the wall with another semi-nomadic structure behind it.  Nomadic if movable by fork lift fits your definition of nomadic.  In any case, for the sake of convenience the wall of a yurt is usually constructed in sections so that each section is of a size that is easy to lift and not too wide to transport.

And heres a shot that tries to show the curvature of the lattice wall.  Hard to visualize this sort of thing until you actually build the wall.

Intersections of the wall slats are held together with clinched nails, that is nails whose tips are bent over and hammered down and buried in the wood.

Heres a view of the junction from the other side where the tip of the nail is buried in the slat.





And here is one section of the wall, all folded up into a 30 inch wide section.  When unfolded, this represents 24 feet of wall.

When the two sections of wall are joined as shown here (temporary joint made with clamps) the wall is complete.  And the 96 inch long slats at an angle make the wall 72 inches tall.

The other two ends of the two wall sections will get connected to a door frame, not yet built.  Note alternating colors of wood.  I had enough old redwood deck boards to make almost the whole wall but had to buy a few extra doug fir two by fours to top off the number.  The redwood was free and light.  The doug fir was about ten dollars total and stronger than the redwood but also heavier.  We will see how they hold up over time.
Stay tuned for door frame, roof and canvas cover yet to come.
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"Ford thwart"... or "forward thwart." The front seat, in other words. (This nautical terminology thing is fun).

In any case, I got the basics of the thing built over the weekend. The construction is essentially the same as the rear thwart, although it was a bit trickier to measure for this one. 

With the rear thwart, I had both the frame and its cutouts for the seat risers to use as reference points. Since I did not install the full-length seat risers, (as the boat was designed to have), and since the forward thwart is mounted several inches aft of the forward frame, I first had to figure out where the seat riser should be. Then I could use that as a beginning reference point.

To get to the point, the originally-designed seat riser does not move parallel to the keel. The keel, in fact, is angled downward from the transom to the bow. The sheer line is angled upward from the transom to the deck. Who knows if the seat riser is on a level line? (I suppose I would, had I not lost the drawings at some point.)

The point is, the forward thwart is actually mounted higher than the rear thwart. The way Im building the seat supports, the seats on my boat will actually be parallel to the keel. Based on my measurements, the forward thwart should have been some 2-1/2 to 3 inches higher than the rear thwart. Put simply, I didnt want it that high. So, I built the center support to 9" in height... one inch taller than the rear one.

Next came measuring the seat dimension from side to side. Again, not easy. To boot, the inward curve of the sides of the hull meant a considerably more angled trapezoid shape than the rear thwart. The complexity of the shape made it easy to mess up.

I wont share my dimensions here, because I measured them too short, and cut them even shorter. Executive decision: move the thing forward until it mates to the sides, rather than re-measure and cut a new one.

Actually, that was a pretty easy decision to make. Sure, it will mean that whoever is sitting up front will have to sit facing backwards, if they want to be comfortable. However, this arrangement actually maximizes the available space between the thwarts, providing the most available legroom for everyone. Besides, if I put oars on the boat, Ill have to sit backwards to row it, anyway.

Enough gabbing. Lets look at the pictures:



Opening up the center space like this should give plenty of legroom for up to 3 people in the boat. 

The sides of the forward thwart were cut at a 30° bevel to match the sides of the hull.
Oh yes, one last update: I epoxied the bow eye into place. I filled the hole up with thickened epoxy, pushed the bolt through, tightened it, and scraped away the mess. It shouldnt be going anywhere.
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Jumat, 15 Juli 2016

It was such a glorious fall day, that I really needed to see the boat out in the open.  Additionally, it is so much easier working when you can stand up without bumping your head!  The building frame rolls out on four 2" PVC rollers.  It is so easy to move, that I needed to watch the speed we were going at!  When the boat is in the garage, I can now easily slide the whole thing against the wall, or move to the center.  This is now a much more usable space and more comfortable to work in.  Oh, the seat frames are finished.  Now its on to the centerboard.  


out in the daylight.  
Nice lines.  But, someone get the shop vac out before the photo is snapped.  

I also trimmed the bulkheads that were standing a little high, and then trimmed the seat sides so that it is all level in preparation for installing the centerboard trunk.  


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Selasa, 12 Juli 2016

The inwales are glued in place with the temporary screws removed.  I am trying to use as few metal fastenings as possible to keep the cost down.  The System 3 Epoxy is quite strong itself.  I have filled and taped the center seam and the forward bulkhead as well as the stem.  Here are some photo updates.

forward bulkead as seen from inside.  All taped. 

view of the center seam looking aft.  It is clear to me at this point that there is no way the keel batten will go in without modifying of removing the center frame.  

View of the center seam at the forward bulkhead looking forward.  The patch on the bottom is barely visible at this point in time.

view looking forward.  The seat risers and inwales are clearly viewed from this perspective.  

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