Friday, April 11, 2014

El Toro Trailer, Updated

You probably don't remember but a while back, I did a posting on kayak trailers that could be towed behind a bicycle.  The tow bar on that one broke.  The fundamental problem on that one was that it was made out of a fairly skinny piece of redwood that just wasn't strong enough.  This time I used oak.  Oak is stronger but the bar sticking out from the trailer is still about 8 foot long and so it flexes quite a bit.  When you're pedaling, the rhythmic motion of the pedaling sets up a back and forth oscillation of the trailer which is not only annoying but also slows down progress.
There it is with an El Toro loaded up for a test run. The length of the tow bar might seem extreme, but it has to be long enough to tow 20 foot (7m) kayaks.
I knew how to fix the oscillation problem which is by adding some cross braces in the form of a triangle, the universal stable polygon. But due to lack of ambition, I never got around to it.  But since the tow bar broke and I had all the tools out to replace it, it was time to add the bracing as well.  Mission Accomplished! as George Bush would say.
And the view from the rear.  The El Toro, an invention of the Richmond Yacht Club is 8 foot long and 4 foot wide.
Tow bar triangulated with two side braces for lateral stability.
And the link from the tow bar to the bicycle.  I should shorten that. Next time.

Desert Storm Tan Repaint

Over the last few years I have been painting the skins of my skin on frame boats with polyurethane varnish.  The varnish has UV blockers in it that protect the synthetic boat fabric from degradation by the UV.  The fabric I use is either nylon and of  late, mostly polyester.  Both get degraded by UV more or less equally.  Degradation means the fiber loses its flexibility and strength and crumbles into dust.  This is not a good thing in a boat skin and so it must be prevented.
In the past, I would try to touch up the varnish.  That worked for a little while but new polyurethane does not adhere well to old polyurethane.  The touch up varnish when exposed to sunlight for about a year starts to peel off.
Here's the original latex painted boat,  exposed to full sun for over two years already with no visible damage to the paint.
The solution as it turned out is latex paint.  Latex paint sticks to degraded polyurethane varnish and it effectively blocks UV radiation and it also is more flexible than polyurethane and does not crack.  Coincidentally, the polymer used in latex paint is acrylic, same stuff that they make UV resistant fabric like Sunbrella out of. You might ask, why not just cover the boats in sunbrella.  Good question.  I suspect it has to do with the price of sunbrella.  And you still have to paint the stuff to make it waterproof.
Here's the King Island kayak about to get a coat of tan paint.  Note the previously yellowish varnish starting to turn a chalky white, a clear sign that is near the end of its life.
The paint I was using was free give-away stuff left over from repainting about an acre's worth of commercial buildings in the neighborhood.  The commercial buildings have not peeled and neither have my boats.  Only drawback to this paint is its color, an unattractive sort of Desert Storm Tan.  Oh well, I also have four gallons of Gulf of Tonkin Gray.
And here is one of my baidarkas with a new coat of Desert Storm Tan or maybe it should be called, Afghanis-Tan or would you prefer Afghanistan-Tan
In any case, I painted about 4 boats yesterday.  Six left to go.

Wednesday, April 9, 2014

Basic Technology by Michael Wolf

Michael Wolf is a photographer working out of Hong Kong and possibly other cities.  A while back I ran into his photos of what he called "Bastard Chairs."  I would have picked a more flattering term, but bastard chairs is probably what most people would regard them as.  In any case, these chairs are what you get when people who are not professional chair makers improvise on chair repair.  They are in a sense, folk technology.  Go to the link to see more examples.
Housing is another area where folk technology proliferates.  And Michael Wolf has done photographs of that as well in a photo group called The box men of Shinkuju Station.
How does this relate to skin on frame kayak technology?  Well, given a need, people will invent a way to make do with what they have.  That is the essence of most primitive technology.  In our own very compartmentalized world where everything has to be done by experts we are usually isolated from folk technology and instead overwhelmed by what we commonly think of high technology.  But inject poverty and take away the money that it takes to fund the expert technologists, voila, up pops folk technology like mushrooms after a rain.