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Re: Navels to Nutshells
By:Eric
Date: 3/19/2003, 9:10 am
In Response To: Re: Apples to Oranges (C. Fronzek)

: These are just two different approaches to the same end. The Inuits used what
: they could get their hands on and over time made a good job of it. The
: original Walrus was designed by Norman Skene to use 1920's technology.

* Inuit would use huge logs of seasoned deal fallen into the water in Siberia. They lacked nothing but plywood, which they didn't need (not available for marine construction in the 1920es, AFAIK) as they wouldn't make folding boats. They've been working their skills over several centuries, no doubt waiting for an energetic, straw-hatted Messiah to prove them wrong. Putz states in his book that his design is Greenlandic, but I've never heard of such a construction among Arctic kayaks types.

: Dimensional lumber,screws and glue. Skene was a navel architect.

* Screws rust, go figure.

There is no reason to think that he would produce a kayak frame that would blow : apart while on the water.

* No, we scarcely hear such craft explode on farm ponds, but they could suffer a slow undoing that could bode disaster as well.

: The Walrus is much more rigid because of the trusswork sides that form a
: beam. I can't figure why anyone would find fault with this setup.

* I do. It shouldn't be so rigid. Not a skin-on-frame at least.
Gunwales made of slant, short stanchions set at alternate inclinations can't be compared with Inuit gunwales each made of one long plank that have their grain set along the length of the boat.
On a definite downward bend, the stanchion which goes up will be compressed, while the next that's going up will be stretched. But both are too short for their structure to eat up that push, and pull.
They're weaker than the stringers, and won't fight them eternally. In a kayak woodwork, it's the stronger, thicker stringer that leads the dance. The rest can only react. And as the stanchions work in opposite directions, the gunwale tends to gradually take apart, while the steel screws work inside the wood to weaken the fastenings.

A variation of this is found on the most expensive kayaks made. Klepper
: stiffens its' frames by joining the top two stringers on each side with
: plywood panels. It may look different but it's a beam that does the same
: thing as Skene's trusswork.

* Plywood works differently than lumber. More, the Klepper's plywood stations are set perpendicularly to the deckbeam, gunwales (also made of ply), etc.
See from the side, this amounts to a series of rectangular compartments.
Thanks to Klepper special fittings, such rectangles can deform to take a lozenge's shape, though barely to the extent of inches or fractions of a inch.
Klepper plywood gunwales must limit the vertical flex of the structure, but as they're made of ply panels, the pull works evenly within the width of each panel, in a much more homogenous way. Stringers are glued all along to the gunwales' panels.

Please look up page 15 in Putz' book, an tell me if you trust his approach:

"Most treaties, books and articles (hark! competitors? how dare they?) about boatbuilding are too precious and patronizing (c'mon dude, don't mess about with those fastidious faggots, let us real men have fun) for our purposes here (which purpose? isn't it to build a seaworhty kayak ?). They emphasize the tremendous strain that the sea places on boats (I guess our engineer never saw a steel hull crushed by a wave from his spacecraft).
They harp on getting long, clear pieces of expensive wood species (home depot, or, horresco referens, from the local carpenter's, fir banks and other luxury items for the happy few) and grades (which grade exactly? waterproof grade or stainless fir?), that bend easily, can be glued (he himself later recommends glueing and screwing altogether as "probably" a safer method) and fastened effectively (fancy that!), resist to rot, do not corrode fastenings (this takes the cake!), and are beautiful (all queer tarts who paddle with their boa on, 'told ya).
Well, our kayak looks like a boat, acts like a boat, and is a boat, but building it is not boatbuiding in the usual sense.[...] Their natural disposition is to be stored indoors, used for short periods, and then dried out and stored again."

* Inuit store their traditional craft in the outdoor.
Next page he describes the many gorgeous wood species he used on his own boat (but don't worry, he just found them in his outhouse)!

Eric

: If your in a hurry build a Walrus. If you've got time to burn (and don'y mind
: some string burns) stitch up an Inuit hull.
: Charlie

Messages In This Thread

Skin-on-Frame: Putz vs. Morris
Tom -- 3/18/2003, 7:43 am
Re: Skin-on-Frame: Putz vs. Morris
Paul G. Jacobson -- 3/18/2003, 9:35 pm
Re: Skin-on-Frame: Putz vs. Morris
Tom -- 3/19/2003, 7:56 am
Re: Skin-on-Frame: Putz vs. Morris
sing -- 3/19/2003, 8:11 am
Re: Apples to Oranges
C. Fronzek -- 3/18/2003, 7:49 pm
Re: Navels to Nutshells
Eric -- 3/19/2003, 9:10 am
Re: Navels to Nutshells
Bill Price -- 3/19/2003, 1:19 pm
Re: Navels to Nutshells
Eric -- 3/19/2003, 4:13 pm
Re: Navels to Nutshells
Mike Hanks -- 3/19/2003, 6:13 pm
Re: Navels to Nutshells
Tom Yost -- 3/19/2003, 2:27 pm
Re: Skin-on-Frame: Putz vs. Morris
Eric -- 3/18/2003, 8:53 am