Re: [Paddlewise] Durability

Michael Daly wrote:

> John Myers wrote:

> > Has anyone out there experienced hull failure
> > in a fiberglass or composite boat that could be attributed to an overly
> > light layup? What boat and under what conditions did it fail?
> 
> It's not easy to compare realistically the strengths of kayaks that have
> failed under different conditions.  Anecdotal evidence tells us less than
> an instrumented kayak.  Also, there are other details besides the shell
> construction.  The bulkheads, coamings, hatches and other details
> contribute to the overall strength and stiffness, so you'd have to compare
> different versions of the same boat.  Make a Romany Explorer using the
> best vacuum bagging techniques and good woven cloth then compare it
> to a Brit built battleship version.  That'd tell us.

I think Mike's point about the low validity of anecdotes is a good one.  Even
so, it is useful to know which boats have broken under "normal use," and what
steps manufacturers have taken (might take?) to prevent breakage.  In that vein,
I offer the following anecdotal evidence for Eddyline's Wind Dancer:

Old layup (pre-1990):  oil-canned in big surf (before I bought it) ahead of the
cockpit.  Serious cracks in the hull/deck seam, and lesser ones in the deck. 
Hull was unaffected, AFAICT.  I fixed these problems, at the cost of a few
pounds of resin and glass.  My assessment:  I believe this layup was never
intended to survive 6-7 foot surf in the impact zone, and was too light in the
deck region.  I'd call this a case of misuse of the boat.

Newer layup (vintage 1993; seems about the same weight as the earlier boat): 
stress cracks in gel coat on the rear deck, from self-rescue-induced
oil-canning.  My assessment:  layup is too light, and flexes unacceptably.  No
kayak should yield that much when I slide my fat bod onto the rear deck!  (This
boat also had a 4-inch diameter tree limb fall on the very top of the deck,
about 2.5 feet in from the bow, and only shows gel-coat cracks.  Asessment: 
plenty tough for tree-limb attacks.)  Also has a couple gel-coat cracks aft
where some yardape over-tightened polypro line to keep the yak on a rack on a
Zodiac.  Assessment:  I blame the yardape for this one.

If I buy another Eddyline boat, I will check the layup of *the deck* for too
much flexure, and suffer the extra weight needed to stiffen the boat.  My field
use is not abuse.

-- 
Dave Kruger
Astoria, OR
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