Re: [Paddlewise] Evaporative cooling with Goretex

rdiaz_at_ix.netcom.com wrote:

> Re: what to wear, wet suit, dry suit------
> 
> [This] outfit (Goretex jacket; neoprene farmer john) is right on
> as a great insurance policy at minimum financial outlay and with maximum
> flexibility.  [snip]

> I also have a coated nylon dry suit (Stohlquist).  And I get funny
> here.  While I accept Goretex for a jacket, I still don't trust it for a
> dry suit.  With a jacket that is going to let water in a bit anyway via
> the non-latex neck and via the waist (snug but not watertight), I can
> accept that the Goretex may not work well at some point.  In a dry suit
> where your whole existence depends on it not letting anything in,
> goretex failure would be catastrophic.  I think a fully coated suit is
> warmer than a Goretex one since it does not breath.  The action in
> Goretex that lets body moisture through perforce lets out body
> heat...that is the way the process works.  If I am wearing my dry suit,
> conditions are really cold and I want to keep in body heat.  Of course,
> it may also be that I have a perfectly good suit and want to justify not
> spending $500 for a Goretex replacement.  :-)

Hmmmm, Ralph, you are making me think again, darn it!!  <G>

I don't own nor have I used a fully coated dry suit, so my comments may be
off the mark.  Nonetheless, I think if I had access to one, and an
equivalent Goretex unit, I might use the latter, and expect to be warmer,
*in the long run.*  Here's my rationale, though I'd be interested in the
experience of others (since I have none with fully-coated stuff):

Ralph makes a good observation:  that evaporative cooling from body
perspiration, passing through the Goretex, will increase cooling.  In my
experience, most of my sweating occurs when I am working hard, and I am
*plenty warm* at those times.  So evaporative cooling is not a problem
then.  Sometimes, after working up a sweat, and stopping for a while
(lunch, etc.), I cool off a little.  Usually I put on a warmer hat or
something.  During those rest breaks, the Goretex is still transpiring
water, so evaporative cooling is a significant heat-transfer mechanism (re:
conduction, anyway), but because I temporarily don some warmth, evaporative
cooling is not a problem then, either.  When I go back to paddling, I
generate some warmth, and evaporative cooling is again not a problem.  At
the end of the day, my insulating garments are a little moist, but are
still highly functional in insulating me,  **because the Goretex has
allowed my body moisture to escape.**

That's where I think the Goretex would be vastly superior.  In a fully
coated garment, I think all my insulation would be a *lot* wetter, and I'd
have to shed it while setting up camp and unpacking (etc.), and deal with
drying it out somehow.

The other factor which may negate any advantage the fully coated stuff
might have is that rain, paddlesplash, etc., will wet the outside of either
garment, giving lots of evaporative cooling from non-anthropogenic water.

So, what is the experience of others?  Is the fully coated stuff warmer,
despite what I *think* will happen?  (A good theory is just a good theory; 
experience judges theory.)

-- 
Dave Kruger
Astoria, OR
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