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From: <KiAyker_at_aol.com>
subject: [Paddlewise] Kevlar question
Date: Mon, 22 Mar 1999 07:14:23 EST
   It has been suggested to me that one can save weight in a Kevlar boat by
foregoing the pigment in the hull. Is this true? Just how much weight does the
pigment add? Are there any other pros and cons to ordering a Kevlar boat I
should know about? I guess I really don't know that much about Kevlar.

Thanks for the help,

Scott
So.Cal.
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From: John Winters <735769_at_ican.net>
subject: Re: [Paddlewise] Kevlar question
Date: Mon, 22 Mar 1999 07:32:15 -0500
>   It has been suggested to me that one can save weight in a Kevlar boat
by
>foregoing the pigment in the hull. Is this true? Just how much weight does
the
>pigment add? Are there any other pros and cons to ordering a Kevlar boat I
>should know about? I guess I really don't know that much about Kevlar.
>
It is not the pigment that get left out but the gel coat. The gel coat is
the layer of pigmented resin on the surface that provides the shiny gloss
etc. This layer is typically applied about 0.0015" thick and weighs roughly
(varies with pigment weights) 0.054 lbs per square foot (according to one
gel coat supplier).

Gel coat has little structural value. Better protection for the laminate
can be obtained by painting with one of the two part marine polyurethane
paints at less than 30% of the weight.

Cheers,
John Winters
Redwing Designs
Specialists in Human Powered Watercraft
http://home.ican.net/~735769/

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From: Hank Hays <lhays_at_canby.com>
subject: Re: [Paddlewise] Kevlar question
Date: Mon, 22 Mar 1999 07:45:10 -0800
Scott,

>   It has been suggested to me that one can save weight in a Kevlar boat by
>foregoing the pigment in the hull. Is this true? 

Yup, but it doesn't work exactly like you think it does.  The pigment is
usually contained in some thickened resin, the part they call "gelcoat,"
applied to the outside of the boat.  A typical sea kayak would probably
have about three pounds of gelcoat on it.  The gelcoat acts as a cosmetic
and sacrificial layer only, adds no structural strength for it's weight.
If you are into cosmetics you'll want the gelcoat, but most of us buy boats
to paddle, not just look at.  

Gelcoat is on both fiberglass and Kevlar boats.  What it does is take the
scrapes and bumps that the strength members of the boat (fiberglass and
Kevlar would suffer if it wasn't there.  In the process it can gouge, star
crack, and chip, and flake off, etc.  That's better than the strength
members taking that abuse, but the glass and Kevlar don't abuse as easily
as the not strong gelcoat.  Gelcoat also looks pretty until it scratches
and starcracks, and chips.... which is soon if you bought the boat to use,
and not just look at.  Maybe some people take better care of their boats
than I do?  (almost certainly) 

Clear gelcoat is available and often used in Kevlar boats to let that
expensive Kevlar show through.  Sort of like the price tags on Minnie
Pearl's hats (or am I showing my age here?).   It does the same thing,
protects the strength members underneath (for a while), but doesn't look as
pretty cause you're looking through it at the stuff underneath.  Clear
gelcoat should have ultraviolet inhibitors in it as Kevlar is UV sensitive.
 Not bad though.  The surface of the Kevlar fibers darken with UV exposure,
which then blocks UV from getting to the interior of each fiber.  It's a
surface phenomenon only and us manufacturers don't worry about the
resulting insignificant structural losses, just the cosmetic effects, which
usually does take a few years.  

Boats with a "skin coat" rather than a gelcoat are available, though not
all manufacturers make them.  That's where the boat is made without any
gelcoat at all.  The Kevlar or the fiberglass is the outside of the boat.
Often more expensive cause the manufacturer has to do a really pretty job
of making the boat (pigmented gelcoat hides errors).  Same with clear
gelcoats, though.  The resin used for the skin coat can be pigmented,
usually at an insignificant weight penalty, though it seldome hides the
Kevlar very well, and may be pretty ugly if the Kevlar is the outside
structural fabric.  That's a color choice.  Ask the manufacturer of the
boats you are considering what the options are. 

Good luck,

Hank Hays
Lightning Paddles

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From: Nick Schade <schade_at_guillemot-kayaks.com>
subject: Re: [Paddlewise] Kevlar question
Date: Mon, 22 Mar 1999 11:17:59 -0500
The gelcoat is not required, but you don't want to forego pigment all
together. Kevlar breaks down when exposed to UV. The pigment will provide
protection.
Nick


At 7:14 AM -0500 3/22/99, KiAyker_at_aol.com wrote:
>   It has been suggested to me that one can save weight in a Kevlar boat by
>foregoing the pigment in the hull. Is this true? Just how much weight does the
>pigment add? Are there any other pros and cons to ordering a Kevlar boat I
>should know about? I guess I really don't know that much about Kevlar.
>
>Thanks for the help,
>
>Scott
>So.Cal.
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Nick Schade
Guillemot Kayaks
10 Ash Swamp Rd
Glastonbury, CT 06033
(860) 659-8847

Schade_at_guillemot-kayaks.com
http://www.guillemot-kayaks.com/

>>>>"It's not just Art, It's a Craft!"<<<<


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From: Steve Jernigan <jernigan_at_chester.uccs.edu>
subject: Re: [Paddlewise] Kevlar question
Date: Mon, 22 Mar 1999 10:51:48 -0700
At 07:14 AM 3/22/99 EST, KiAyker_at_aol.com wrote:
>   It has been suggested to me that one can save weight in a Kevlar boat by
>foregoing the pigment in the hull. Is this true? Just how much weight does
the
>pigment add? Are there any other pros and cons to ordering a Kevlar boat I
>should know about? I guess I really don't know that much about Kevlar.

 The folks at Wenonah tell me that their gel-coat process adds about 6lb to
the weight of a 16.5ft canoe. This is not the same thing as adding pigment
to the otherwise relatively clear epoxy, which I wouldn't expect to add
noticeably to the overall weight. There is some argument regarding kevlar
deterioration with exposure to UV, which the gel-coat should largely
prevent. I prefer not to carry the extra weight, and so store my boat in
the garage. 
 For comparison, my Wenonah C1W solo boat with an ultra-light core layup,
aluminum trim, and no gel-coat weighs 32.5lb according to my NIST traceable
bathroom scale ;-). M'ladys Wenonah Prism has the flex-core kevlar layup
with a white gel-coat but is otherwise very similar. It weighs 43lb on the
same irrefutably accurate scale.
 I feel that there are two advantages to kevlar. One, for the same weight
fabric, kevlar is probably 50% stronger than fiberglass. This means that a
kevlar boat can have less fabric and hence less weight. Some manufacturers
will offer boats with an "expedition" kevlar layup. These boats have more
or heavier fabric layers in them and so weigh about the same as a
fiberglass layup, but are substantially stronger. Two, if you do stress the
kevlar lay-up enough to buckle it, the epoxy will crack, but the fabric
generally stays intact and temporary repairs are easily made with duct
tape. Often when fiberglass lay-ups buckle the fibers part and you are left
with a hole. Also, for the same reason, kevlar layups are somewhat more
resistant to puncture wounds. 
 IMHO, unless you are greatly deterred by the 30-40% cost differential, by
all means get a kevlar boat.
 My $.02, but hope it helps a bit.
ByeBye! S.
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From: Bob Denton <BDenton_at_aquagulf.com>
subject: RE: [Paddlewise] Kevlar question
Date: Mon, 22 Mar 1999 13:13:03 -0500
How did you get he canoes in the bathroom?

At 07:14 AM 3/22/99 EST, KiAyker_at_aol.com wrote:
>   It has been suggested to me that one can save weight in a Kevlar boat by
>foregoing the pigment in the hull. Is this true? Just how much weight does
the
>pigment add? Are there any other pros and cons to ordering a Kevlar boat I
>should know about? I guess I really don't know that much about Kevlar.

 The folks at Wenonah tell me that their gel-coat process adds about 6lb to
the weight of a 16.5ft canoe. This is not the same thing as adding pigment
to the otherwise relatively clear epoxy, which I wouldn't expect to add
noticeably to the overall weight. There is some argument regarding kevlar
deterioration with exposure to UV, which the gel-coat should largely
prevent. I prefer not to carry the extra weight, and so store my boat in
the garage. 
 For comparison, my Wenonah C1W solo boat with an ultra-light core layup,
aluminum trim, and no gel-coat weighs 32.5lb according to my NIST traceable
bathroom scale ;-). M'ladys Wenonah Prism has the flex-core kevlar layup
with a white gel-coat but is otherwise very similar. It weighs 43lb on the
same irrefutably accurate scale.
 I feel that there are two advantages to kevlar. One, for the same weight
fabric, kevlar is probably 50% stronger than fiberglass. This means that a
kevlar boat can have less fabric and hence less weight. Some manufacturers
will offer boats with an "expedition" kevlar layup. These boats have more
or heavier fabric layers in them and so weigh about the same as a
fiberglass layup, but are substantially stronger. Two, if you do stress the
kevlar lay-up enough to buckle it, the epoxy will crack, but the fabric
generally stays intact and temporary repairs are easily made with duct
tape. Often when fiberglass lay-ups buckle the fibers part and you are left
with a hole. Also, for the same reason, kevlar layups are somewhat more
resistant to puncture wounds. 
 IMHO, unless you are greatly deterred by the 30-40% cost differential, by
all means get a kevlar boat.
 My $.02, but hope it helps a bit.
ByeBye! S.

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From: <rdiaz_at_ix.netcom.com>
subject: Re: [Paddlewise] Kevlar question
Date: Mon, 22 Mar 1999 13:31:17 -0800
Bob Denton wrote:
> 
> How did you get the canoes in the bathroom?
> 
> At 07:14 AM 3/22/99 EST, KiAyker_at_aol.com wrote:
> >   It has been suggested to me that one can save weight in a Kevlar boat by
> >foregoing the pigment in the hull. Is this true? Just how much weight does
> the
> >pigment add? Are there any other pros and cons to ordering a Kevlar boat I
> >should know about? I guess I really don't know that much about Kevlar.
> 
>  The folks at Wenonah tell me that their gel-coat process adds about 6lb to
> the weight of a 16.5ft canoe. This is not the same thing as adding pigment
> to the otherwise relatively clear epoxy, which I wouldn't expect to add
> noticeably to the overall weight. There is some argument regarding kevlar
> deterioration with exposure to UV, which the gel-coat should largely
> prevent. I prefer not to carry the extra weight, and so store my boat in
> the garage.
>  For comparison, my Wenonah C1W solo boat with an ultra-light core layup,
> aluminum trim, and no gel-coat weighs 32.5lb according to my NIST traceable
> bathroom scale ;-). 

I was wondering the same thing but I have been told that bathroom scales
can be removed from their locale.  Same with faucets.  I am planning to
bring one on my next camping trip so I can always have a steady supply
of water.

ralph
-- 
-----------------------------------------------------------------------
Ralph Diaz . . . Folding Kayaker newsletter
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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From: Steve Jernigan <jernigan_at_chester.uccs.edu>
subject: RE: [Paddlewise] Kevlar question
Date: Mon, 22 Mar 1999 12:36:11 -0700
At 01:13 PM 3/22/99 -0500, Bob Denton wrote:
>How did you get (t)he canoes in the bathroom?
>

Squished 'em up real good -n- stuffed 'em inna Duluth pack. Kevlar fabric
still intact, tho. 
Now where's that duct tape? ;-)
S.
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From: Bob Denton <BDenton_at_aquagulf.com>
subject: RE: [Paddlewise] Kevlar question
Date: Mon, 22 Mar 1999 13:52:10 -0500
Is a bathroom scale a bathroom scale if it's not in the bathroom?


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From: Joe Pylka <pylka_at_castle.net>
subject: Re: [Paddlewise] Kevlar question
Date: Mon, 22 Mar 1999 15:31:04 -0500
>Is a bathroom scale a bathroom scale if it's not in the bathroom?
>
    If you're weighing the bathroom then it's a bathroom scale.  But if it's
in the bathroom while you're weighing then you have to subtract the weight
of the scale..........


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From: <DANJW_at_aol.com>
subject: Re: [Paddlewise] Kevlar question
Date: Mon, 22 Mar 1999 19:14:16 EST
In a message dated 99-03-22 14:12:12 EST, you write:

I was wondering the same thing but I have been told that bathroom scales
can be removed from their locale.  Same with faucets.  I am planning to
bring one on my next camping trip so I can always have a steady supply
of water.

ralph
 
I have also heard that but have yet to try it. I do, however, bring along a
car door so that if it gets too hot I can roll the window down.

dan
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From: Larry Mills <millsl_at_purchase.edu>
subject: RE: [Paddlewise] Kevlar question
Date: Tue, 23 Mar 1999 19:01:28 -0000
I have only used one of those scales to weigh my bathroom.

I prefer to weigh my kayak on my special kayak scale.  I got
it on the internet from some guy in Canada that designs kayaks.

I also got a really good Canadian Ballast Rock scale from the 
same guy.

I was also trying to figure out whether or not to put pigment in
the gelcoat on my ballast rocks.  If I don't, will there be any
UV damage to the rocks?

Larry Mills
Department of Redundancy Department



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From: Dan Hagen <dan_at_hagen.net>
subject: Re: [Paddlewise] Kevlar question
Date: Tue, 23 Mar 1999 11:50:55 -0800
Larry Mills wrote:
> ...
> I was also trying to figure out whether or not to put pigment in
> the gelcoat on my ballast rocks.  If I don't, will there be any
> UV damage to the rocks?

Yes, without a doubt (unless you protect them in some other way). I once
saw a pair of rather old ballast rocks in Manitoba that had only been
covered with a clear skin coat. While they looked really nice (you could
see the natural texture of the granite), the UV degradation was so bad
that I was able to punch my finger into the rocks; they simply crumbled.
So if you don't use gelcoat, make sure that they are painted, or that
you add a UV inhibitor to the clear coat.

Dan Hagen
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From: Jim Champoux <jim_at_sigall.com>
subject: Re: [Paddlewise] Kevlar question
Date: Tue, 23 Mar 1999 16:20:41 -0400
>Dan Hagen wrote
>So if you don't use gelcoat, make sure that they are painted, or that
>you add a UV inhibitor to the clear coat.

way off topic but it reminded me of an old Air Force saying: "if it moves,
salute it, if it doesnt move, pick it up, if you cant pick it up, paint it"


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From: Christopher E. Bush <chris.bush_at_stratos.net>
subject: RE: [Paddlewise] Kevlar question
Date: Tue, 23 Mar 1999 14:44:15 -0500
> 
> Date: Mon, 22 Mar 1999 12:36:11 -0700
> From: Steve Jernigan <jernigan_at_chester.uccs.edu>
> Subject: RE: [Paddlewise] Kevlar question
> 
> At 01:13 PM 3/22/99 -0500, Bob Denton wrote:
> >How did you get (t)he canoes in the bathroom?
> >
> 
> Squished 'em up real good -n- stuffed 'em inna Duluth pack. Kevlar fabric
> still intact, tho.
> Now where's that duct tape? ;-)
> S.

Thus creating a "scale model" of said canoe?

Chris
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From: John Winters <735769_at_ican.net>
subject: Re: [Paddlewise] Kevlar question
Date: Wed, 24 Mar 1999 07:42:48 -0500
-----Original Message-----
From: Larry Mills <millsl_at_purchase.edu>
To: 'Joe Pylka' <pylka_at_castle.net>; Bob Denton <BDenton_at_aquagulf.com>;
rdiaz_at_ix.netcom.com <rdiaz_at_ix.netcom.com>; Paddlewise (E-mail)
<PaddleWise_at_lists.intelenet.net>
Date: March 23, 1999 1:51 PM
Subject: RE: [Paddlewise] Kevlar question


>I was also trying to figure out whether or not to put pigment in
>the gelcoat on my ballast rocks.  If I don't, will there be any
>UV damage to the rocks?


Genuine Canadian Ballast Rocks do not exhibit any deleterious effects from
UV . All date from Precambrian times and have been tested thoroughly. We
have heard reports of rocks falling apart without UV inhibitors in the
coating and on investigation discovered that these rocks originated in
Silicone Valley and have built in obsolescence.  We have no knowledge that
Bill Gates is involved although some of the rocks have a geeklike
appearance.

Cheers,
John Winters
Redwing Designs
Specialists in Human Powered Watercraft
http://home.ican.net/~735769/

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