Showing posts with label on. Show all posts
Showing posts with label on. Show all posts

The Giant Sequoia and Some Random Thoughts on Trees and Wood

It is one thing to see wood at a lumber yard and it is quite another thing to see it in the form of a living tree.  Unlike the stuff in the lumber yard which gives little evidence of where it came from, the living tree obviously speaks for itself.  It is not a product but an individual being with a considerable amount of character that makes it distinct from others of its kind, especially when old.
The musings I am about to deliver on the nature of wood were prompted by a trip to Kings Canyon and Sequoia National Parks.  The two parks are adjacent to each other, with Sequoia to the south and Kings Canyon to the north.  The only way to approach these parks by car is from the Central Valley of California.  Kings Canyon is adjacent to the city of Fresno and Sequoia is adjacent to the city of Visalia. Giant Sequoias can be found in both parks, although Sequoia National Park has more of them. Coming from the Central Valley which is flat and almost devoid of trees except for fruit trees in the orchards, it is hard to imagine that one is about to enter a mountainous zone where the huge sequoias live. 
But on to some pictures. I would like to say off the start that it is impossible to convey the massiveness of these giant trees in photographs.  The best one can do is show part of the tree with a human or two next to it for scale.  But even then, the photograph cannot capture the sense of presence that these large trees convey. Nevertheless, here are some photographs.
This trunk of a Sequoia has been hollowed out by fire and decay and so it is possible to walk through and along the trunk. 
 
Here is another sequoia that has fallen.  Someone cut a hole through it that one can walk through. The hole by the way is about seven feet tall.

Here is a picture of the tree named the General Sherman.  This is the worlds most massive living being.  It is suspected that some of the trees cut down when logging first began were larger than this, but General Sherman is currently the largest individual.  Its diameter at the base is in excess of 30 feet. 
 

 And here is the root ball of a recumbent sequoia, 30 feet from side to side.
 And using a deer for scale.
 And more humans for scale.
 And a tree hugging human for scale.
Even the branches of these trees are huge.  This one fell off a tree and the park service left it laying where it fell to give people an idea of their large size.  The largest branches on the General Sherman are about 7 feet in diameter.


 

The sequoias are not the tallest trees in the world.  That distinction goes to the coastal redwoods.  Neither are they the oldest trees. That distinction goes to the bristlecone pines of the White Mountains, one valley to the east of the Sierra Nevada.  But the sequoias are the most massive trees. Their trunks seem to be columns of almost constant diameter rising some 300 feet into the air and then seeming to end abruptly in the older specimens.  

Someone took a slice of a sequoia trunk and propped it up at an angle for the edification of the public. This slice represents roughly 2000 years of growth.  Age is determined by counting the annual growth rings.  The age of standing trees has to be estimated because there apparently is not any equipment that can remove sample cores of the requisite length, roughly 18 feet needed to count all the rings from the center of the tree to its edge.

 This is a side view of that specimen.

 

And here is a closeup of the growth rings in that slice.  The top of the picture is closer to the center of the tree where the older wood resides.  The crack running horizontally through the picture is a fire scar.  Moving downward toward the crack, the growth rings get ever closer together, an indication of ever diminishing growth.  After the fire, there is an explosion of new growth that again diminishes over time.  Apparently, fires burn the vegetable matter on the ground and release nutrients into the soil which spur new growth for a few decades until most of the nutrients are once again tied up in vegetable matter until the next fire comes along.  Also, note the little circular impressions just above the crack.  These are probably cores taken for carbon 14 dating and then plugged. 
When botanists try to estimate the age of trees based on diameter, they look at slices like this one and try to get an average count of growth rings per inch since as this picture shows, ring density changes with every fire and also with annual precipitation.

There was no sign indicating what sort of wood these park benches were made out of, but I suspect that they were made of sequoia wood. Yes, they haven;t stopped logging sequoias.  Not all of them are protected. Some of them are on private property and some of them are in national forests which are administered by the US Department of Agriculture which regards forests as cropland meant to be harvested. Not an editorial comment by the way. If we want to make stuff out of wood, we have to cut down trees.  More on that at the end.

Here the park service has done a prescribed burn or someone dropped a cigarette. In any case, not much damage was done.  For a long time, the park service used to suppress fires but found that periodic fires are better than monster fires fueled by debris on the ground that has accumulated for too long.  Also, they found that sequoias will not reseed very well without fire.  Fire turns vegetable matter into ash, releasing nutrients for the seedlings to grow.  Fire also kills off young trees that would otherwise shade out the new seedlings. And fire also opens up the cones to release seeds.  So now the park service does prescribed burns which do little damage but reduce the amount of fuel that could produce more dangerous fires.

This picture shows young sequoias coming up with the older fire scarred sequoias in the background.  The ash and the light also allow ferns to grow.

Another view of the burned ground.  Yes the ground burns since the top six inches are a compacted mass of needles and small branches.
Almost every old tree shows fire scars. As a matter of fact, I have never seen so many burned trees as I saw in Kings Canyon National Park.  In the national forests, fire scarred trees are more rare since those are logged over on a more regular basis and fires tend to be suppressed because the trees are regarded as a crop, not a part of an ecosystem in which fire plays a beneficial role.
This is a side view of about eight inches of fibrous sequoia bark which lacks resin and therefore does not burn readily.  Bark on sequoias can be up to two feet thick and this is what lets them grow old in an environment where fires occur naturally every seventy years or so.
Here the fire burned into the trunk of the tree but the segment at the left is still alive.  Every yearn the bark spreads sideways to cover over scars and in time will cover them completely.

 

Here is a segment of  a branch. The heart wood is red and the sap wood is a lighter color.  The heart wood of the tree is dead.  The sapwood is the part of the tree that is still alive and growing and is where the tree adds more wood around the outside of the tree under the bark. For purposes of lumber we want heart wood because the sap wood decays more readily.
So I was curious what kind of wood sequoias are made out of or perhaps more properly, what kind of wood they grow.  Right on the ground near this broken branch above I found a small piece that had broken off when that branch came down.  It was red in color like that branch but on carving some off, I found that the red color was mostly a product of weathering and that the wood was a lighter color.  It was also surprisingly light, similar to redwood but with a consistency that felt more like cedar.  And then it occurred to me, why not?  If you are going to grow large, why not build yourself out of light wood.  Since most of the weight of the tree is in the trunk, the lighter it is, the larger you can build it.  Sequoias and other conifers dont have huge spreading branches like oaks and so most of their strength is needed to resist the compression of the mass that piles up on top of the roots, mostly in the trunk.  Hardwoods like oak on the other hand that put out large lateral spreading branches need stronger wood to resist bending forces and stronger wood is heavier.  And so boat builders like conifers because they produce long straight trunks that can be cut into long straight boards.

As a boat builder I use wood. And as a paddle maker I also use wood, especially wood from older trees since they are the ones that have the wood that is clear of knots. But to use wood without a knowledge of what happens to the forests where that wood is taken from is akin to buying a pork chop in a supermarket without knowing that one needs to kill pigs in order to make that pork chop.
The impact that the visit to the sequoias had on me was to see trees as individuals.  Young trees a few decades old, especially in large quantities tend to be rather similar in appearance and lack distinction as individuals.  Every tree seems to look like every other tree and so one can more readily regard them as a crop to be cut for use as lumber.  Old trees however, tend to be distinctive, each one different from the next and since in the case of the sequoias they may have been around for perhaps two thousand years or more, one is forced to realize that cutting one of those trees for human use deprives the rest of the world from the presence of such old trees for another two thousand years.  And so it seems that to cut such old trees is rather frivolous because the gain in lumber does not make up for the loss of the presence of the individual.  
And yet, as a wood worker, I use wood.  And since I make objects for other people, I want to give them a good product free of flaws and blemishes.  I want to give them something that looks like wood is something that is extruded by a machine. 
Perhaps I need to rethink my approach.  If I do not want to participate in the cutting of old trees, then perhaps I need to figure out a way to make paddles from younger trees whose wood is not quite as perfect and blemish free as that of older trees.  Stay tuned, I have some younger trees in mind that I will experiment with


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Skin on Frame Housing the yurt gets a roof

Progress on the yurt continues.  Much of the progress is imperceptible to anyone but myself but the progress is there.  As it turns out, my initial suspicion that my first yurt would be a prototype for working the kinks out of the design turned out to be true. So let me share what Ive discovered so far.
 I got the crown on the central ring of the yurt.  I used some kayak rib stock, 1/4 inch by 3/4 inch white oak, socketed into the central ring and lashed together with tarred seine twine. The idea behind the crown is that it will be open under normal conditions but covered when it is raining or heat needs to be kept in the yurt.
Another discovery I made after the initial assembly of the yurt was that for the sake of getting a good setup it helped to trace a circle on the ground first before erecting the walls so that the walls would form a perfect circle.  The perfect circle is essential so that all the rafters are the same distance from the central ring.
I also discovered that I had much more wood in the central ring than I needed and so it was too heavy and difficult to get into position when no help was available. What I did to remedy the weight problem was to cut some of the extra wood away from the center of the ring.  It was way stronger than it needed to be. 
 The next step was to cut out some fabric for the roof.  It took me some time to work out the trigonometry for the roof cover shape, but I did it.  But I have learned to distrust theory and test with an actual life size cover.  The other reason for getting the cover in place was that a series of rain storms were coming into the area and that would be a good test to see how the cover would stand up to the wind.
Heres an inside shot of the cover.  The wind lifted it some and pushed it off center.  Part of the problem is that the shape of the cover is like a pie with a wedge cut out of it and the edges adjacent to the missing wedge get pulled together and glued or sewn resulting in the desired pyramidal shape.
The cover is made out of some sort of vinyl covered fabric that is used for advertising banners.  A friend gave me a bunch of these banners and I cut them up to fit the roof. The fabric has two problems.  One is that it is very heavy and the other is that it is very stiff.  The combination of weight and stiffness makes it very difficult to pull this stuff up on the roof.  The weight also works against its portability.
On the plus side, the cover survived the storm and did not get blown off.  I also discovered that once again, there is nothing like building something to test a design because until you do, its next to impossible to know what sort of problems the design has.  So far, none of the design elements have been complete failures but lots of them can use improvement.
The list so far.
The wall battens are slightly too flexible.  A bit more stiffness is advisable even at the expense of greater weight.
The skin is too stiff and heavy.  Lighter weight is advisable.
Other commitments have kept me away from the yurt, but the learning continues.  I will continue to post whenever there is progress or even when design ideas fail.
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Fitting the Utility’s port side planking — and a little more progress on the Zip

Having previously used the starboard side planking as a template to draw and cut the port side, fitting the port side planking was relatively quick and simple. Busy days full of other obligations have meant that I’ve had to work on the boat incrementally... 20 minutes here, 45 minutes there... but, its getting done.

Thanks to a little help from my daughter, I’m now most of the way through driving the screws to hold the planking down. The new DeWalt titanium drill bits I bought have been a real pleasure to work with, particularly since my older ones had become almost too dull to use.

Dry-fitting the forward port side planking.

February brought with it an unusual amount of snow this year. In addition to school cancellations, there were a few days when I got snowed-in at home. I took advantage of these days to draw out the construction drawings for my Zip on a big sheet of eucaboard.  I drew the frames out as they would overlap one another, based on their shared x,y axis & set-up level. This will be a great reference for checking  the frame parts for accurate shape & for assembling the frames. It is also a very useful tool for checking the relative dimensions of various aspects of the hull.


My Zip construction drawing on a big sheet of eucaboard.

Last Christmas, I received a copy of How to Fiberglass Boats, by Ken Hankinson, along with the accompanying DVD. I finished reading it recently, and I’ve enjoyed watching the DVD. It’s useful information for those, like me, with minimal experience at working with fiberglass. It takes a lot of the mystery out of the process, and its very helpful to watch someone else actually doing it. 

Additionally, the book is very enlightening about precautions to take when working with epoxy.

With any luck, Ill be able to fiberglass the Utility’s hull before summer.


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Epoxy work on seats sheer and Zip parts

The last post left off with my having cut out a piece of Meranti for the rear seat. This weekend, I laminated that onto the A/C exterior plywood... and did a little more epoxy work along the way.
1/4" Meranti top for the rear seat
Just as Id done with the front thwart, I coated both mating sides with epoxy (not thickened), and held them together with concrete blocks and weights while the epoxy cured. I had just enough epoxy left over to also add a 2nd layer to the Zip transom knee.


Laminating the Meranti onto the rear thwart. I used the extraneous epoxy to encapsulate the underside of the front thwart, as well as the transom knee for the Zip.
Regrettably, however... after the epoxy cured, there remained a small gap.

And a dust bunny got stuck in the epoxy on the Zip part.
All this didnt go perfectly according to plan. After the epoxy had cured, I found a gap between the two layers that would need to be filled. Also, some dust had gotten stuck in the epoxy on the Zip transom knee. I am trying for substantially better fit and finish on the Zip, so I sanded off the dust bunny & planned to encapsulate with a third layer.

Logistically, I thought it best to encapsulate the undersides of both seats next. This would be the 2nd coat for the forward thwart. I planned to tilt the rear thwart just a little so that epoxy would run into the gap and fill it. Since I havent trimmed the Meranti top yet, this should help the epoxy flow down into the gap. With the extraneous epoxy, I planned to encapsulate the underside of the sheers on the aft third of the boat, as well as the Zip part.

I ended up having more left over epoxy than expected. So after quickly cleaning them off, I also encapsulated part of the Zip stem and the forward face of frame 5-1/2.


More encapsulation; trying to fill the gap on the aft thwart. Here it is propped up slightly with a scrap of mahogany left over from the quarter knees.

Epoxy drying on the Zip stem & frame 5-1/2.


Current Status of Zip Parts
PartStatus
Stem & Breasthook AssemblyMost surfaces have 1 coat of epoxy
Frame 5-1/2Forward face has 2 layers of epoxy. Other surfaces have 1 layer.
Frame 4Side members cut, but have not been planed or notched for sheer.
Transom KneeCoated with 3 layers of epoxy
TransomSide frame members cut 1/4" oversized on outer side. Have not been planed.
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More fairing on the Utility This time the transom

Warm greetings from Barnacle Mike’s crowded little boat shop. You know, one of the great things about the boatbuilding community is the fact that you meet some really cool people, both online and in person. The level of support and insight that you get from more experienced builders who kindly share their knowledge and give advice can truly help a newbie keep pushing his or her project forward. I’m very thankful for that.

An online boatbuilding friend, who has also been kind enough to follow my blog, sent me an e-mail the other day asking about the status of the Utility. It does seem like I’ve been paying a bit much attention to the Zip project lately. Truth is, I have still been slowly, slowly... s-l-o-w-l-y... fairing away at the Utility all the while. Still, his inquiry about its status gave me a little more motivation to get off my “transom” and put more elbow grease into getting the little boat past the fairing stage. (Thank you, Paul!)

So, that’s just what I did Saturday, fairing away at the transom sides until they were finished. The starboard side had a bit more excess material than the port side. So, I roughed it in with the belt sander, then worked it the rest of the way down with the mouse sander. Unfortunately, I did not follow the “best practice” of checking my work frequently with my test piece of plywood. (I thought the transom sides would be a no-brainer. I was wrong.) When I tested my “finished” work with the plywood, expecting to feel a broad smile cross my face as I witnessed my handiwork, I was disappointed to see several gaps appear. The culprit was an overly sharp bevel in a couple of spots. More gaps to fill with thickened epoxy. I’m getting pretty good at that, if I do say so myself.

Needless to say,  I was more cautious with the port side. I also went about it a little differently. This time, I started by carrying the line of the sheer and chine through the transom material first. Then, I “connected” the two spots by fairing the area in-between. This time I alternated between the mouse sander and a small block plane. I worked slowly and purposefully.

The results were much, much better.

I do still have a good bit more fairing to do, primarily in the mid-section of the boat. I also have to make a decision about the chines in that area, (more on that later). I could’ve worked on all this Sunday. However, yours truly decided he needed some time on the water. So, I spent the day canoeing. I’m sure you understand.

By the way, I met another boatbuilder out on the river. He was piloting a very nice-looking red drift boat upriver. It looked about 16’ long. The handsome-looking boat glided smoothly through the water, pushed by a silent electric trolling motor. He proudly said “yes” when I asked if he’d built it himself. He had some very nice things to say about Don Hill’s drift boat plans before we each went our separate ways. 

Yep. You’ve gotta love the boatbuilding community.

Starboard transom-chine joint after fairing.

Starboard transom-chine joint after fairing.
Starboard transom-chine joint after fairing

Starboard transom-sheer joint after fairing. As you can see, Ive got a heck of a gap in that "Marine-Grade" plywood that Im going to have to fill.



Port transom-chine joint before fairing.

Port transom-chine joint before fairing.
Port transom-chine joint after fairing.

Port transom-sheer joint before fairing. Notice all that epoxy thickened with #2 silica?

Port transom-sheer joint after fairing. I still have some thickened epoxy to file away.


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On the Evolution of Kayaks

There is a notion drifting around the skin on frame kayak world that skin on frame kayaks benefit from 4000 years or so of evolution.  The implication is that skin on frame kayaks were about as well adapted to their environment as could be.  Well, maybe.  But I want to express some contrary opinions on the topic. 
First of all, kayaks were designed and not evolved.  Evolution is imagined to proceed by random changes to a design which is then approved or rejected by the environment.  Kayaks are built by humans who by virtue of experience and ability to communicate with other kayak builders have some knowledge of what makes them work.  As a consequence, changes to kayak design are not random but rather, directed. So human designs can change rapidly and become optimized in a much shorter time than evolved designs. 
Secondly, evolution as imagined, only benefits current conditions.  That is, evolutionary fitness is potentially lost if conditions change.  If there was a major change in conditions, say 500 years ago, then both the 4000 year old and 1000 year old design would have to adapt, one design having to throw 3500 years of evolution on the junk pile and the other only 500 years of evolution. 
Actually, this is what happened.  All kayak designs were thrown on the junk pile when modern petroleum powered boats were developed.  Kayaks as a species went extinct in the arctic but mutated into recreational craft and migrated into industrial cultures to the south.


In addition, little is known about kayaks older than 400 years.  So whether they evolved in the sense of "improved" in the last 4000 years is strictly speculation.  I would imagine that kayaks of 3000 years ago were probably as good as kayaks 1000 years ago. I would think that one hundred to two hundred years would be sufficient to refine a design about as much as was possible.  After that, improvements would be minimal.
What did probably happen in the Arctic was that conditions changed periodically.  Since the kayak was a hunting craft its success had to be judged by its ability to bring its builder within range of prey.  If prey changed or hunting conditions changed old adaptations might have to be discarded and replaced by new designs. 
And the last big change to kayak designs happened roughly 400 years ago when European whalers showed up in the arctic, bringing with them steel tools and later, milled lumber.  Steel tools allowed a range of joinery in kayak frames that was previously inaccessible.
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Incremental progress on the first bottom plank

So, cautiously and methodically, I have continued fastening down the first panel for the bottom planking.

Using a 4-foot ruler as a straight edge, I drew reference lines on the plywood to show placement of the floor battens. That made it much easier to mark the places to drill holes & drive screws. Marking the chines for screw placement has not been so easy. I’ve had to cut away enough overhanging material so that I can use my marking gauge — the same spring clip & duct tape arrangement I used on the side planking. I used the Porter Cable multi-tool saw to cut away plywood as I worked my way forward... cutting new plywood washers as I went.


Bottom panel, before much extraneous material was removed.

Looking forward, you can see the panel begin to curve and twist.

Reference lines for the battens helped greatly with screw placement.
Near the forward frame, the plywood begins to curve and twist considerably. At times, it seemed like I just couldn’t bend it any more without breaking it. I followed the technique outlined in Boatbuilding With Plywood, and cut away as much extraneous material as I could, while still leaving myself adequate material to work with. It is amazing how much easier plywood will bend when excess material is cut away.


Here, a good bit of material has been removed from the panel. It became much easier to bend.

For now, my progress has stopped at the forward frame. I’m just inches away from the transition joint. To mark the approximate cut line up forward, I coated the corner of the side planking with a lumber crayon & bumped the bottom planking panel against it to transfer the mark. It worked reasonably well. Soon, I’ll remove the bottom panel, cut near this line, and re-attach the panel for further fitting.

The transferred line on the inside of the panel should help greatly when I remove the panel & trim it down further.
 Once this panel is cut to shape, I’ll be able to use it as a template for the other panel.
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Musings on how to make the seats

The original Glen-L plans call for a seat riser that runs from the forward frame to the transom, passing through this cutout in Frame #1.

So, Im in this "blocking" phase. The next step is to attach blocking on the sides of the hull to support each end of the rear seat. (Basic "bench" seats are also called "thwarts" in nautical terminology.)

The original plans call for a full-length seat riser to be attached to the sides of the hull. Thats the purpose for the unique cutouts on the sides of Frame #1 that youll see on the Glen-L Utility model. So far, there arent a whole lot of well-documented Utility builds. However, among those Ive seen, most do not use the full-length seat riser. Instead, these builders simply attached blocking to support the seats.

The original plans also call for 2 separate aft seats, on either side of the boat. Im not going to do that. I want a simple back thwart, and front thwart.


Glen-L line drawing of the Utility
I debated on the full-length seat riser. However, I decided against it for a few reasons. One is time, as Im now quite anxious to get this boat in the water. Another is the fact that Id have to either cut the frame cutout more, or plane the full length of the seat risers, because my cutout is less than a "store-standard" 3/4" depth. A third reason is the fact that Id also have to make another cutout in the seat riser itself, to accommodate the butt blocks that connect the side panels of the hull.

Nope. Simple blocking it will be.

The next question is, "How to attach it?" I realized that if I install the blocking on either side first, then Im taking something of a gamble on them actually being on exactly the same plane. I do not want my seats to slant, obviously.

The other matter to attaching the blocking on the sides first, is the fact that Id have to retrofit the center support. I have already planned to build a different type of center support than Glen calls for, anyway.

How my center supports will differ:
Glen calls for 2 plywood center supports for the front thwart. These supports are glued to either side of the keel, and then attached to either side of blocking that is underneath the thwart itself. Like this:


Glen-L Utility
A Glen-L Utility at the "G8" Glen-L Gathering in 2014. Thanks to the kindness of this boats owner, I was actually able to drive this one & take one of my children out in it. Note the construction of the center support under the seats.
Im planning to build a different type of center support, based on one I saw in a photo of a 1935 Riva. Mine will have a single plywood support, mounted on top of the keel, on the centerline. I will have 1" x 1" blocking on either side of the plywood support, both at the top and bottom.

Center seat support on a 1935 Riva
Back to the point...
I had another idea. What if I build & install the center support first, then make sure the thwart is level... then, use the thwart itself as a point from which to install the blocking on the sides? It seems to me that Id stand a better chance of having the seat installed level, once its all done.

So first, I marked the sides, where the top of the blocking (seat riser) should be, at right angles to the frame. Then I taped twine from measured points on these lines, stretched across to the other side. Measuring the height from the keel to the twine, I found that each point was 8 inches.




I plan to make the thwart 12 inches wide. I want the center support to be slightly narrower, so I decided it should be 10 inches. Knowing that I plan to use 1" blocking, I then had the dimensions I need to draw out the center support.


Half-breadth of the seat support, drawn out on the computer.
So, I drew the half-breadth of the seat support in Adobe Illustrator & printed the pdf full-size. I then cut out the print & traced it, full width, onto poster board. Once I cut that out, I had a template which I can now transfer to the plywood.

Poster board template for the center support. So far, so good...

The next step is to actually build it. 

Lets hope all this works.



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