Sunday, August 12, 2012

Old Kayak, Bent Ribs & Buckliballs

In my previous post, I described how one of my kayaks spontaneously changed shape in response to a shrinking skin.  While this type of response would generally have been regarded as mechanical failure, researchers are now trying to steer this kind of phenomenon to make it perform useful tasks, that is by creating a variable shape that can adapt to conditions.

Buckliball changing from large to small (left to right) in response to external stress

Paraphrasing here - One stress makes you larger, one stress makes you small, and the stress that mother gives you don't do anything at all. Never mind.  Pause for groans to subside.
geodesic dome assembly
By the way, if you didn't grow up in the sixties, which is likely, you probably missed Buckminster Fuller and his geodesic domes and also buckyballs which he invented and which I suppose buckliballs is a pun on.

Friday, August 10, 2012

Old Kayak, Bent Ribs

I've got one more set of photos on deck for the old kayak series.  Not that I don't have more old kayaks or old kayak photos, but it's a matter of being able to find them.

Today's tale of woe is all about the lethal combination of heavy nylon fabric and a boat left out in the sun for too long.  Nylon, if you don't already know, contracts with high temps and as you can see in the photos, pushes down on the keelson and bends the ribs into a reverse curve.  This isn't that bad, mostly it makes the hull a little flatter.  What is worse is the end to end shrinkage of the fabric which compresses the keelson which responds by taking on something of an S curve when viewed from above.  This makes the boat pull to one side.  But even that is not lethal and I managed to fix it with a rudder.  It's just that the boat is not the elegant craft that you started out with. So beware of heavy nylon combined with heavy sun.

Thursday, August 9, 2012

Old Kayak, Old Paint, Part 2

For the premise of this post, go back one post.  This post is about yet another instance of a paint job gone wrong.  Not functionally wrong, just esthetically wrong, though not entirely, not in my estimation anyway.
 I took these pictures just before repainting the hull of my favorite Unangan kayak, (baidarka).  The reason I was repainting was not that the finish looked spotty. I actually liked the look, sort of organic, but rather that there was wear in the base coat that was letting water leak in.
The original sealer on this boat was varnish which gives the boat a vaguely rawhide colored look.  But I wanted something darker like rawhide that's sat in a museum for 200 years.  I was able to achieve that look, or so I thought until I questioned other people what it looked like and they said it looked like tree bark.  What I had done was mix oil color with varnish and I painted that over the original varnish coat. 
If I had read the label on the varnish I would have found out that once the varnish is fully cured, you need to sand it before you try to paint over it.  As you might guess, I just painted without sanding and so after about a year or so the new paint turned brittle and on exposure to sun started flaking off a little at a time.  As I said, I liked the look - kind of like lichen on a rock or a seal with the mange, but I finally had to throw in the towel on this paint job and scraped and sanded and then covered it over with a coat of gray latex paint.

This Old Kayak, Old Paint, Part 1

People occasionally write me to ask whether they can use this or that material or process in the building of their boat.  I sometimes have answers for them and more often do not.  When I don't, I like to tell them to try whatever it is they are asking about and they will find out if it works or not and then they will be the experts on that particular topic.
In any case, I try a lot of stuff, more or less indifferent that a lot of it won't work.  I also am casual about boat storage so most of my boats are subject to accelerated aging. I also like to use off the shelf, not yacht approved materials to see whether there is a cheap way out of any particular conundrum.
So let's move on to today's topic, Old Paint. No not the horse.  Old paint that has turned dry and brittle and stressed and developed cracks.  To be more specific, old varnish.  Because the substrate of the varnish on a skin on frame boat is a flexible fabric, impact on the skin causes fractures in an interesting way. So proceed and feast your eyes on a variety of stress cracks in old varnish on a nylon skin.  Enjoy.
A small running critter.  The green flecks are fake gold leaf I put in the varnish.  The gold is actually brass and has oxidized to a green.

stretch marks.

Southwestern US petroglyph, what of, I'm not sure.

and a braid.

More stretch marks.

This one kind of looks like an ancient shrimp fossil.

This one, I'm not sure, kind of like a cartoon bird in flight.

Yup'ik Science

If you have $45 to spare you might want to pick up a book called The Way We Genuinely Live: Masterworks of Yup'ik Science and Survival.  The book is of the coffee table genre and lavishly illustrated with color photos.  The book reflects a fairly recent trend of including native commentary on native objects, in this case, Yup'ik artifacts in the collection of the Ethnologisches Museum Berlin.
It is the commentary by several Yup'ik elders who traveled to the museum that makes the book especially worthwhile.  It is their stories and reminiscense that makes the objects come alive.
One of the things that struck me in reading this book is that no comparable book exists for the Aleut culture.  I wonder of course why this might be and my theory is that the Yup'ik culture was not colonized and consequently changed much until recently.  The Aleut region by comparison was discovered by Russians in 1741 and quickly colonized thereafter.  Colonization for the Aleuts meant first of all a decline in population of some 90% within 50 years of Russian arrival.  This meant that there was a much smaller population to carry on the culture. Secondly, the surviving members of the culture were pressed into service by the Russians and integrated or subjugated to their economy.  This meant that traditional ways of making a living were severely impacted. 
I don't know much about the history of the Yup'ik region but I suspect the decline of their traditional culture came much later because they had nothing much that European Americans were interested in, and as a consequence were mostly left alone.  It was the sea otter and the fur seal that interested the Russians and apparently the Yup'ik were lacking in these and so concentrated on the Aleutian region instead.
In any case, it is fortunate that Ann Fienup Riordan has organized this book and recorded the fascinating history of Yup'ik artifacts.
The book is a welcome departure from the usual catalogs of Arctic artifacts that do little more than name the objects illustrated and the place where they were collected and leave us to guess how they were used.