(no subject)

My experience is much greater with fiberglass and composite kayaks than with
wood and skin on frame kayaks. I suspect Nick has a somewhat opposite
background and viewpoint given his different business focus. I would like to
respectively disagree with a few of the points he makes while agreeing with
mnay of the others.

Nick wrote:

>>>>>A wood boat is no different than a fiberglass or plastic boat in that it
will scratch. The difference is the scratches are easier to see. But they
don't do any more damage. By "damage" I mean something that will harm the
function of the boat. Most scratches can be fixed with a new coat of varnish
at some point.<<<<<<

Most scratches are immaterial on either construction but a deep scratch in a
wood cored kayak should probably be fixed or at least waterproofed with some
waterproofing agent so that water doesn't migrate too far into the wood core
to soften or rot it.  >>>>>>Strip-built and stitch and glue kayaks are
actually not wood, they are fiberglass boats with a wood core, and any drop or
hit that would physically damage the boat's structure would likely do the same
damage or worse on a pure fiberglass boat. Again, the difference is that it is
easier to see.<<<<<<

Most lightweight wood kayaks have a single layer of fiberglass on the outside
of the hull and just varnish on the inside. The fiberglass adds a waterproof
abrasion resistant layer but most of the strength and rigidity is in the wood.
Putting a single fiberglass layer both the inside and outside of the wood core
makes the wood kayak as heavy as a similar sized fiberglass kayak but also
adds some strength and stiffness due to the I-beam created (and the thickness
of the wood core). This is stronger than a foam core fiberglass kayak with a
single layer of glass on each side of the foam. The foam core makes a very
stiff, but brittle, kayak that is also subject to damage from smaller hard
blows (or just air tiny bubbles in the fiberglass layers that let in water in
a few spots--that became soggy and softer--and added weight). I think wood
makes a better core material than foam, at least when it comes to strength. A
rigid kayak is less subject to damage from strong folding forces than a more
flexible kayak but is likely more subject to damage from hard blows (and with
folding forces, if damage occurs, it will likely be more catastrophic with a
stiffer kayak).
Fiberglass kayaks vary widely in how strong they are for a given weight. This
is primarily due to the materials and process used and the fabric to resin
ratio. Fiberglass kayaks are generally tougher than wood kayaks because they
are more flexible and are usually made from materials with similar elasticity.
If materials are mixed (kevlar layer next to graphite layer or wood layer next
to fiberglass layer for instance) then bending forces from a blow are more
likely to cause delaminating between layers which weakens the structure some
depending on how extensive the damaged area is. While a wood kayak can be very
strong and durable I don't think it can stand up to the same abuse that a good
fiberglass lay-up of the same weight can. The differences might depend
somewhat on what happens to cause the damage though because each construction
type has their own strengths and weaknesses.


 >>>>>>>A "spider crack" in the gel coat on a glass boat is hard to see, but
indicates fairly systemic damage to the underlying structure. On a wood boat,
the same impact would make a small, localized bruise that may require
extensive work to make disappear, but is not all that significant from a
structural standpoint.<<<<<<<<<

This is simply not true (and is the reason I chose to respond to Nick's post).
Fine 'spider-web" cracks in the gelcoat of a composite kayak are mostly of no
consequence what-so-ever (other than to bother the owner and make them worry
about them). The reason they occur is because the thin gelcoat surface is far
more brittle than the underlying fiberglass reinforced layers. If the kayak
bends outward or takes a hard enough blow where the laminate bends outward at
some point it puts the thin gelcoat layer under more tension than it can take
and results in fine cracks where the gelcoat layer separates from itself under
tension. Rarely is the underlying glass seriously damaged and rarely does the
gelcoat even flake off. If you can see a whitened area (looking from the
inside glass side) the laminate has been bruised (minor delaminations between
layers--or between the gelcoat and the glass--or pulled strands of glass in
the fiberglass laminate make the area whiter than the undamaged areas). This
is also of no serious consequence and nothing needs to be done. If you can see
or feel rough broken glass fiber ends protruding from the damage area (inside)
then it is time to put a fiberglass patch over the area to prevent a possible
leak and to restore the strength to the area. You are unlikely to see broken
underlying fibers unless it is also obvious that the gelcoat has broken and
flaked away in some spot on the outside of the kayak (rather than just be thin
spider web cracks you can safely ignore). >>>>>>>>I find that people have a
different attitude with wood boats and a scratch that would not bother them on
a glass boat is cause for much gnashing of teeth on a wood boat. So, if it is
important to you that the boat stay "stunningly beautiful" then wood is
probably not the best choice for rough use. If you don't mind a patina of use
then wood boats will hold up just fine. You can always paint the boat so you
can't see the effects of hits as easily, after all this is what gelcoat is
doing for a glass boat. Personally, I think a wood boat, well beat up, still
looks better than an old fiberglass boat with faded gelcoat.<<<<<<<<

As a former kayak retailer I can assure you that it isn't just wood kayak
owners that can be picky about the most minor of scratches to their shiny
fiberglass/gelcoat baby (and want to fix them). Most would do far more harm
aesthetically in trying to fix them--even if done professionally at great
cost--than to learn to live with a few scratches and quit worrying about them.
Those who have a deeper scratch, one deep enough that they can see light
through the laminate because they have scraped off the.(012" to .020" thick)
thin opaque gelcoat layer, are often sure their kayak needs immediate repairs.
Actually, 99% of the time that scratch can also be ignored unless it has also
gone through several layers of fiberglass cloth as well as the gelcoat (which
is very rare). In the late 1980's or early 1990's I ran our demo Mariner II at
full hull speed into a steep shore of sharp edged big volcanic rubble in Baja
(it was much like river rip-rap in size and slope). The smaller volcanic
stones tinkled just like glass and had the same sharp edges (but had a very
fine grain so weren't quite obsidian). With much banging and clattering, the
bow ended three feet (vertical) up those sharp edged boulders and I was having
to do extended paddle braces just to reach the water to brace (and not turn
over like a turkey on a spit).  The bow then slid back down the boulders into
the water and amazingly I was still upright. The result was some gouges and
scratches in the gelcoat around the bow (and of course some white gelcoat left
behind on the sharp points). That white kayak remained as my demo and I still
have it. Since gelcoat scratches with a whitish scratch the gouges weren't
even that noticable unless one looked for them. Right now you may be asking
yourself: why would he do such a thing to a kayak? Well, the answer is, I
didn't do it on purpose. It was a pitch black night and the phosphoressence in
the water was the brightest I'd ever seen it. So bright it hurt my dark
adapted eyes when I looked right at it (like flipping on a light switch can
do). Once my eyes adapted to the brightness I was busy watching the flow
patterns of water around the paddle the phosphoressence revealed. I paddled
faster and faster while watching closely for what I might be able to learn
about paddles and strokes by closely watching those glowing organisms move. I
thought I was going parallel to the shoreline but the shore hooked around up
ahead in the blackness and I hit it square on at full sprint.

While we all have biases concerning aesthetics (and even I think nicely done
clear finish wood kayaks are the most beautiful of all), I think Nick is not
comparing apples to apples though when he talks about faded gelcoat on a
fiberglass kayak vs. scratches on a wood kayak. Faded gelcoat is the result of
lots and lots of sun exposure--most likely from storing the kayak out in the
sun. Given the same sun exposure, a clear finish wood kayak would suffer far
more damage (and fading of the wood--even with a UV resistant finish).
Further, with gelcoat a fine abrasive polish can bring back the old shine with
just a little rubbing. The sun damage done to the wood kayak would be far
deeper (and a polyethelene kayak might be rendered so brittle as to be
dangerous by that much sun exposure). Of course an opaque painted wood kayak
would fair far better than a clear one (but would also be likely to end up
below a good fiberglass kayak on my aesthetic's scale). Just ask a fiberglass
sailboat owner about how much above the waterline work he does to the
fiberglass areas vs. the usually much smaller area of brightwork.
***************************************************************************
PaddleWise Paddling Mailing List - Any opinions or suggestions expressed
here are solely those of the writer(s). You must assume the entire
responsibility for reliance upon them. All postings copyright the author.
Submissions:     PaddleWise_at_PaddleWise.net
Subscriptions:   PaddleWise-request_at_PaddleWise.net
Website:         http://www.paddlewise.net/
***************************************************************************