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Re: More on pvc frames
By:Charlie
Date: 11/30/2007, 12:25 pm
In Response To: Re: More on pvc frames (Paul G. Jacobson)

I found a pile of wood that someone had dumped along a backroad. It was old tongue and groove, fir porch flooring. Could have been 100 years old. Full of nail holes and only in 7' lengths. There was more than enough to make several excellent SOFs if you knew how to scarf. No guesswork, no experimentation, no cost, no reinventing the wheel.
I used the wood for something else but if I had built an SOF from it I would have been $20 to the good right from the start, would have been on the water in short order, would know that it would go where I pointed it, and would have had no worries that what I had built was going to come asunder when the first wave hit it.
I'll leave kayaks built from PVC pipe, recycled aluminum siding or scrap copper plumbing to those so inclined.

: You are ot the only one. Again, I repeat that this is still in the
: "experimental" stage. It is something to play with. If it works
: out in any manner, then maybe someone will want to try to go further.

: hehehe. That could be why I haven't gotten a boat built from it yet! :)

: Until Pi was known with some accuracy there wasn't much use for math formulae
: related to circles--but that didn't keep people from using circles. They
: just didn't bother with the math, and stumbled thru. The Sci-Fi author
: Robert Heinlein used to make cracks about Indiana still not accepting the
: real value of pi. They had at one time legislated that it be calculated as
: 3, which he thought was absurd. I'm not sure of the whole story with
: Indiana, but next door, in Illinois, there was a time when round barns
: were the craze. The state taxed the barns based on their volume, and for
: round barns they were instructed to use the diameter times 3 to get the
: taxable area. Well farmers knew that with that kind of math, with round
: barns they would have more area than they were being taxed for. I suspect
: Indiana did something similar and just let the law linger long enough to
: become a joke.

: I mention this because the complexity of a subject does not always make it a
: difficult project. There are almost no areas on a canoe which have square
: joints. But we make the parts and components on tools which are set up to
: cut square edges. The discoverers of calculus (Newton and Descarte) would
: look at strip building and hold it in awe. The compound curves of the hull
: are approximated with numerous thin strips. It is the same as breaking up
: the area under a curve into a large number of thin rectangles. It is easy
: to calculate the area of those rectangles, and average out the
: discrepancies. We use sandpaper to eliminate OUR discrepancies. If we used
: thinner strips we would need to do less sanding later on. If we used a
: very large number of very thin strips we'd never finish gluing them.
: Eventually we found the happy balance of 3/4-inch-wide strips--and that
: seems to be the standard size, though people will go with larger or
: smaller widths. I suspect that when more of the kinks are worked out that
: PVC tubes --if they are found to be practical-- will be a fairly simple
: material to use and the construction process will be less complicated than
: Stitch and Glue, or mortised and lashed wood frames for SOF kayaks.

: Good question. Don't have an answer for that yet. That may actually end up
: being more than one question -- and I'd want to have answers for all of
: them. Gotta build a few boats from these materials and try them out. The
: first one or two could take a long time, but once it gets rolling, I'm
: hoping that the primary benefits will be in the areas of lower cost,
: faster construction, easy joints for "folding" (or collapsible)
: kayaks, and plentiful availability of materials. The last part is already
: existing, and stimulates to drive to make use of these resources.

: Long lengths of clear wood are getting harder to produce each year, so the
: cost is slowly rising. People who have the tools and knowledge to produce
: scarf joints spend time to make long lengths of wood out of shorter ones.
: Whiole the price of tools is coming down a bit, so is the quality of those
: tools. People who want to build a boat should not need to invest in a
: table saw in order to build their boat. Replacing the long wood components
: on a kayak with aluminum has been a viable method for several years.
: Aluminum is more expensive than wood. PVC would be about the same price as
: wood, and might be a bit cheaper, as it doesn't need to be sanded or
: painted, and it won't rot.

: I think that when plans come out for a PVC framed boat, such a boat will be
: fast to construct and inexpensive. Ideally you could build such a boat in
: a weekend, and with some experience, maybe make one in a single day for
: under $100. if such a design could be made in a manner which would allow
: it to be disassembled easily for storage--and then reassembled easily for
: use--then you would solve a couple more problems which potential kayak
: owners face.

: So those are the targets. One nice thing I've found about playing with this
: stuff is that it leads me to think about ways in which aluminum, or wood
: could replace the PVC parts--and that leads into new realms of design
: possibilities.

: Thanks for asking

: PGJ.

Messages In This Thread

Skin-on-Frame: pvc frame
Scott Shurlow -- 11/25/2007, 5:05 pm
Re: Skin-on-Frame: pvc frame
Paul G. Jacobson -- 11/29/2007, 2:30 pm
More on pvc frames *Pic*
Paul G. Jacobson -- 11/29/2007, 4:36 pm
Re: More on pvc frames
Charlie -- 11/29/2007, 4:40 pm
Re: More on pvc frames
Paul G. Jacobson -- 11/29/2007, 8:33 pm
Re: More on pvc frames
Charlie -- 11/29/2007, 11:17 pm
Re: More on pvc frames
Paul G. Jacobson -- 11/30/2007, 6:47 am
Re: More on pvc frames
Mike Savage -- 11/30/2007, 5:45 pm
Re: More on pvc frames
Paul G. Jacobson -- 12/1/2007, 12:47 am
Re: More on pvc frames
Mike Savage -- 12/1/2007, 8:10 am
Standing on the shoulders of giants
Paul G. Jacobson -- 12/1/2007, 12:49 pm
Re: Standing on the shoulders of giants
Mike Savage -- 12/1/2007, 6:03 pm
Re: More on pvc frames
Charlie -- 11/30/2007, 12:25 pm
And then there are other technologies . . .
Paul G. Jacobson -- 12/1/2007, 12:01 am
Re: More on pvc frames
Mike Savage -- 11/29/2007, 7:54 pm
Re: Skin-on-Frame: pvc frame
Niven -- 11/26/2007, 2:03 am
Re: Skin-on-Frame: pvc frame
kelly t -- 11/26/2007, 7:34 pm
Re: Skin-on-Frame: pvc frame
Scott Shurlow -- 11/26/2007, 8:02 am
Re: Skin-on-Frame: pvc frame
Niven -- 11/27/2007, 3:32 am
Re: Skin-on-Frame: pvc frame *LINK*
Niven -- 11/27/2007, 3:47 am
Re: Skin-on-Frame: pvc frame
Charlie -- 11/25/2007, 6:22 pm
Re: Skin-on-Frame: pvc frame
Scott Shurlow -- 11/26/2007, 8:09 am
Re: Skin-on-Frame: pvc frame
Charlie -- 11/26/2007, 10:44 am
Re: Skin-on-Frame: pvc frame
Scott Shurlow -- 11/27/2007, 6:07 am
Re: Skin-on-Frame: pvc frame
Bill Hamm -- 11/28/2007, 1:59 am
Re: Skin-on-Frame: pvc frame
Dan Caouette (CSFW) -- 11/28/2007, 2:02 pm
Re: Skin-on-Frame: pvc frame
Bill Hamm -- 11/29/2007, 2:31 am
Re: Skin-on-Frame: pvc frame
Mike Savage -- 11/27/2007, 1:23 pm
Maybe this, instead *LINK*
Dave G -- 11/26/2007, 10:24 am