Underwater surface finish

[Bruce in Bangkok]

I've been watching the olympic swimming and notice that nearly all of
the swimmers wear the new performance swimming suits. I did a bit of
research on the web and came up with the following quote from Speedo:

The LZR-Race suits promise to have 5 percent less drag than Speedo’s
previous best FASTSKIN PRO suits that have helped break world records
in the past year. Speedo also claims swimmers will have 5% better
oxygen intake efficiency thanks to stronger core compression section
along the abdomen area.

I wonder whether this phenomena applies to boats? Should we be
attaching shark skin to our boats?

I have seen the dinghy sailors polishing the underwater surfaces of
their dinghys with 2,000 grit sandpaper and wonder whether this might
actually be the wrong thing to do.

Is there any empirical information regarding the application of this
technology to boats?

Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

[Brian Cleverly]

Take a look at:

http://www.sharkskincoating.com/newsE.asp?newsid=242

Brian C

[Dennis Pogson]

Bruce in Bangkok wrote:
> I've been watching the olympic swimming and notice that nearly all of
> the swimmers wear the new performance swimming suits. I did a bit of
> research on the web and came up with the following quote from Speedo:
>
> The LZR-Race suits promise to have 5 percent less drag than Speedo's
> previous best FASTSKIN PRO suits that have helped break world records
> in the past year. Speedo also claims swimmers will have 5% better
> oxygen intake efficiency thanks to stronger core compression section
> along the abdomen area.
>
> I wonder whether this phenomena applies to boats? Should we be
> attaching shark skin to our boats?
>

The skin from a couple of Great Whites would just about cover my underwater
hull. Do you know anybody who could sell them to me?

Dennis.

[Bruce in Bangkok]

Probably best if you get your own.

[Wilbur Hubbard]

Forget it, Bruce. It would never work on a boat like yours that stays tied
to a dock for thirty years.

Wilbur Hubbard

"Bruce in Bangkok" <decypher_...@signature.line> wrote in message
news:0dpca4tqsdjthn6uc...@4ax.com...

[axolotl]

Bruce in Bangkok wrote:

> I wonder whether this phenomena applies to boats? Should we be
> attaching shark skin to our boats?

> Is there any empirical information regarding the application of this
> technology to boats?

3M made a boundary layer film years ago. Presumably the results were not
stellar, or we would still be seeing it.

http://query.nytimes.com/gst/fullpage.html?res=9B0DE4DD1338F937A35751C0A961948260

Kevin Gallimore

----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.pronews.com The #1 Newsgroup Service in the World! >100,000 Newsgroups
---= - Total Privacy via Encryption =---

[Glenn Ashmore]

Give it a few years. U. Florida has been studying shark and porpoise skin
for some time trying to produce a low friction non-depleting non-toxic
anti-fouling coating for the Navy. Last I heard they were in full scale
testing.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Bruce in Bangkok" <decypher_...@signature.line> wrote in message
news:0dpca4tqsdjthn6uc...@4ax.com...
>

[Richard Casady]

On Sat, 16 Aug 2008 12:14:57 -0400, "Glenn Ashmore" <gash...@cox.net>
wrote:

>Give it a few years. U. Florida has been studying shark and porpoise skin
>for some time trying to produce a low friction non-depleting non-toxic
>anti-fouling coating for the Navy. Last I heard they were in full scale
>testing.

I was under the impression that anti fouling paint, or copper sheets
for that matter, work only because they are toxic.

Casady

[7seas...@gmail.com]

On Aug 16, 10:34 am, axolotl <ke...@shorecomp.com> wrote:
> Bruce in Bangkok wrote:
> > I wonder whether this phenomena applies to boats? Should we be
> > attaching shark skin to our boats?
> > Is there any empirical information regarding the application of this
> > technology to boats?
>
> 3M made a boundary layer film years ago. Presumably the results were not
>    stellar, or we would still be seeing it.
>

> http://query.nytimes.com/gst/fullpage.html?res=9B0DE4DD1338F937A35751...
>
> Kevin Gallimore
>
> ----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==----http://www.pronews.comThe #1 Newsgroup Service in the World! >100,000 Newsgroups

> ---= - Total Privacy via Encryption =---

Seen a boat with the 3M Teflon based undercoat. Did not last long and
was a major bitch to clean off for something that would last and work.

Fred

[7seas...@gmail.com]

On Aug 16, 11:46 am, richardcas...@earthlink.net (Richard Casady)
wrote:
> On Sat, 16 Aug 2008 12:14:57 -0400, "Glenn Ashmore" <gashm...@cox.net>

> wrote:
>
> >Give it a few years.  U. Florida has been studying shark and porpoise skin
> >for some time trying to produce a low friction non-depleting non-toxic
> >anti-fouling coating for the Navy.   Last I heard they were in full scale
> >testing.
>
> I was under the impression that anti fouling paint, or copper sheets
> for that matter, work only because they are toxic.
>
> Casady

Thats true, unless you can find a new material that will not allow
anything to stick. Ever see a barney on a shark?

There were some "Snake Skin" coatings that were rolled on in 6 layers.
Once anything stuck the friction would make the paint layer shed. Ok
but major hassel to apply right.

Fred

[Brian Whatcott]

On Sat, 16 Aug 2008 12:38:29 +0700, Bruce in Bangkok
<decypher_...@signature.line> wrote:

>...Should we be

>attaching shark skin to our boats?
>
>I have seen the dinghy sailors polishing the underwater surfaces of
>their dinghys with 2,000 grit sandpaper and wonder whether this might
>actually be the wrong thing to do.
>
>Is there any empirical information regarding the application of this
>technology to boats?
>
>Bruce-in-Bangkok

Slime has been used successfully as a hull coat. It's a consumable
though.
There have been experimental hulls with clse spaced chines - getting
them right is quite a trick.
And finally, there have been air-blown hulls.....

Brian W

[Glenn Ashmore]

>
>>Give it a few years. U. Florida has been studying shark and porpoise skin
>>for some time trying to produce a low friction non-depleting non-toxic
>>anti-fouling coating for the Navy. Last I heard they were in full scale
>>testing.
>
> I was under the impression that anti fouling paint, or copper sheets
> for that matter, work only because they are toxic.
>

It has something to do with the texture and flexibility. It is apparently a
thick coating that has a microscopic surface pattern that slime spores and
barnacles have a hard time binding to. It also flexes slightly under
varying water pressure so the barnacle cement pops off. A side benefit is
that those little bumps improve laminar flow reducing wetted surface drag.
Sort of like the dimples on a golf ball.

[Martin Schöön]

"Glenn Ashmore" <gash...@cox.net> writes:
>
> It has something to do with the texture and flexibility. It is apparently a
> thick coating that has a microscopic surface pattern that slime spores and
> barnacles have a hard time binding to. It also flexes slightly under
> varying water pressure so the barnacle cement pops off. A side benefit is
> that those little bumps improve laminar flow reducing wetted surface drag.
> Sort of like the dimples on a golf ball.

It is the other way around actually. The dimples of golf balls are
there to trip the boundary layer to make sure you get rid of the
laminar boundary layer.

--
Martin Schöön "Problems worthy of attack
show their worth by hitting back."
Piet Hein

[timmynocky]

I’ve been using this technique on my boats bottom for years. The
doubting Thomases in the boat yard assumed that it was because I was
just too bone idle to prepare the surface properly and that my
painting technique was lousy. But I knew better. Still haven’t got it
quite right though, a few more lumps this year and she should go like
greased lightning.

Mike.

[Ryk]

On Sat, 16 Aug 2008 12:38:29 +0700, in message
<0dpca4tqsdjthn6uc...@4ax.com>

Bruce in Bangkok <decypher_...@signature.line> wrote:

>I wonder whether this phenomena applies to boats? Should we be
>attaching shark skin to our boats?
>
>I have seen the dinghy sailors polishing the underwater surfaces of
>their dinghys with 2,000 grit sandpaper and wonder whether this might
>actually be the wrong thing to do.
>
>Is there any empirical information regarding the application of this
>technology to boats?

The orientation of the surface is very important in determining
whether drag is reduced or increased, thus the effect is much easier
to manage on submerged bodies like sharks or aircraft, rather than
surface craft like sailboats that are subject to varying flow
directions due to wave action, heel angle, etc.

The effect is real. The major problem in application so far has been
that the surfaces are fragile and easily damaged by things like
slings, collision with minor debris, etc. It's not worth it outside
racing, and the RRS prohibit it.

Ryk

[Bob La Londe]

I dunno bout all dat fancy schmancy stuff what youse guys is huffin' bout,
but its pretty common knowledge that in high speed stuff like the racing pad
on the bottom of a modern bass boat, an ultra smooth waxed finish is not as
fast as a scuffed finish. Of course us psychotic bass boat drivers don't
get much chance to compare around here. One run up the river, and you skip
two or three sandbars giving that pad a nicely scuffed finish. They always
seem to be faster coming back down river. LOL.

Bob La Londe
www.YumaBassMan.com