[Paddlewise] Folbot Washboards

A back channel exchange re:  Folbot washboard, posted with Ralph's permision. 
I'd also be intersted in the experiences of others re:  effects of washboard
failure.  Thanks.  
-- 
Dave Kruger
Astoria, OR
--

Dave Kruger wrote:
> 
> Over on the Folbot Forum, the claim was made that the washboards are a vital
> structural element for the Greenland II (and the other models, one presumes).
> And, because of the precarious nature of the hinge which joins the halves, that
> the boat could fail if:
> 
> 1. the hinge pins fail
> 
> and, 2. the boat is subjected to strong upward forces at the ends
> 
> I think what the poster was imagining was the boat in heavy seas, crossing the
> trough at right angles to the wave crests.
> 
> I've had my G II out in 5-6 foot swells and wondered what would happen if the
> washboards failed, but it seems to me the longerons and keel members would
> sustain the shape if the washboard hinge failed.  (I noticed the hinge
> attachments were getting sloppy in my '96 model so I replaced the rivets with
> #10 SS hardware and put large fender washers on the outside of the washboards.
> Much more rigid, now.)
> 
> What do you think about the likelihood of catastrophic failure if the
> washboards go?

To which Ralph Diaz replied:

Dave,

The washboard is _one_ of the things holding the boat together.  But a
lot of redundancy is built into the Folbot and other folding kayaks as
well.  The gunwale side structures with their double tubes and spacer
reinforcements form sort of I-beams that do a lot of the holding
together as does of course the keelboard.  Then of course the crossframe
pieces do a lot too to keep the structure sound and so to do the
longerons to a certain extent especially the beefy ones on Folbots (the
Klepper ones are not as strong and act more to help shape the hull then
to hold the boat together).

If a washboard (or coaming as other manufacturers call this) were to
fail, you would lose some of the boat's integrity and it would start
feeling floppy but it would not break apart.

When I was testing the Aleut back in 1992 or whenever it was, my
washboard broke on one side.  It was where the seatback bolt end went
through the washboard.  Polycarbonate is a material that doesn't do well
with drilled holes and the hole for the supporting bolt for the seatback
cracked up and down and one washboard spit apart at that screwhole.  All
that happened was that the boat got a bit sloppier and I had to hold my
self in position rather than have my back resting on something.  The
most noticeable effect in performance was that the boat slowed down more
than its usual self (the Aleut is slow).  And it came at an unfortunate
time as I was paddling with some recreational paddlers in hardshells.  I
was just managing to keep up with them with the Aleut even with its
natural slowness.  But once the washboard broke, I could not keep up.

I reported this to Folbot and eventually they made a fix in that model
with some bushing protecting the hole from splitting.  I did not mention
it in the review because I felt it was something that Folbot would
correct and no use bashing Folbot over it.  It seemed to have also
happened to some early users of the Aleut and I did have one article in
the newsletter about how one paddler applied extra bracing in the area
of those holes in order to avoid breakage.

[I had a washboard in my G II fail in the same spot when I sat on the washboard
during entry.  The new aluminum washboard should not fail this way.  DK]

Again, to get to your question of cathastropic failure.  A split
washboard won't be a disaster since there is so much redundancy built
into the frame.

The place that you may have to watch out more on any of the folding
kayaks is the keelboard.  I know of the keelboard breaking on a Folbot
double and on a Klepper double.  This happened where the horseshoe and
block connection is made dead center in the boat.  Either the horseshoe
or the block came off.  In both cases it was quite disconcerning and in
the case of one of the crews, they felt that the boat would break
apart.  I feel that they were a bit panicky about such dire consequences
and that the rest of the frame would have seen them through albeit with
a somewhat scary feeling.  The side gunwales, the stringers, the ribs
and the coaming (washboard) would keep the boat together sufficiently
well.

If people are really concerned about this they can try some
experiments.  Take the boat out under controlled conditions _without_
connecting the washboard at all.  The cross frame pieces won't be
connected fully and the skin will look somewhat funny, flapping around
at the cockpit opening.  But the boat will definitely float and move
around well enough and not break apart.

Dave, if you wish to pass this observation on to the Forum, you have my
permission.

ralph diaz

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PO Box 0754, New York, NY 10024
Tel: 212-724-5069; E-mail: rdiaz_at_ix.netcom.com
"Where's your sea kayak?"----"It's in the bag."
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