Re: [PSUBS-MAILIST] No more gel-coat!

["John Pier" <caribsub@coqui.net>]

Test:
take 2 bottles of coka cola (glass), fill them up with concrete.
paint one with antiskid (shark skin aspect) leave the other one clean, check
they weight the same.
take a boat drop the bottles in the water at the same time, a scuba diver 30
Ft below will observe that the clean bottle hits the floor first.
Test performed today off the beach in Puerto Rico, water 75 deg good
visibilty.
A real test worths hundreds of theories
keep your  gel coat......
Herve

----- Original Message -----
From: Rob Carlson <rob.carlson@verizon.net>
To: <personal_submersibles@psubs.org>
Sent: Tuesday, February 27, 2001 11:07 PM
Subject: Re: [PSUBS-MAILIST] No more gel-coat!


> I think the rough sandpaper surface occurs natuarally when you leave the
> submarine in water long enough - it's called barnacles :-)
>
> ----- Original Message -----
> From: "Carl Kem" <dustyut@lasal.net>
> To: <personal_submersibles@psubs.org>
> Sent: Monday, February 26, 2001 11:34 PM
> Subject: Re: [PSUBS-MAILIST] No more gel-coat!
>
>
> > Rich, I don't see why you would be kicked from this list.  As for the
> > sandpaper idea, I never thought of it till you mentioned it, and it
> > sounds pretty darn good to me.  Maybe they should try that with the
> > SSBN's, you think?
> > Carl
> >
> >
> > Richard Gordon wrote:
> >
> > > As I may be getting kicked out of the group soon, I thought I'd better
> > > share this last bit of info before I go. It has to do with drag
> > > reduction. Gel-coat and similar coatings on your submarine cause what
> > > is known as a boundary layer. This a layer of slower moving water
> > > against the surface of the vessel. Studies by various groups have
> > > shown that haing an extremely rough surface creates microscopic
> > > turbulance on the surface, thus breaking-up the boundary layer and
> > > reducing drag dramatically. It is for this reason that sharks have
> > > such rough skin. Other fish do not have rough skin, because unlike the
> > > shark, they use their boundary layer to contribute to their
> > > propulsion. They generate the laminar-flow with their whole bodies,
> > > whereas the sharks only use their tale. So coat your subs in
> > > sand-paper and you'll be okay!! lol Rich
> >
> > --
> > "In times like these, it helps to recall there have always been times
> > like these."-Paul Harvey
> >
> >
>
>