View Full Version : Fairing Flap???

Ron Linton
06-07-2002, 12:52 PM
On page 140 of the "Gougeon Brothers on Boat Construction" is this picture:


Although I mostly like to look at pictures and usually avoid reading words, I did search a few pages for information on the function of the "fairing flap"... Didn't find any. Anyone have any guesses?

Barrett Faneuf
06-07-2002, 12:56 PM
That side of the diagram looks like an "after it's all set up and finished" shot.

I would take the "fairing flap" to be a piece of flexible material like rubber, etc used to ride against the centerboard and make the transition from hull to centerboard more fair.

Sorta like a flexible gasket at the bottom of a door.

.. my $0.02

Bruce Hooke
06-07-2002, 01:02 PM
I think Barrett is probably right but the other interpretation that I think is at least possible is that this is showing the 'fiberglass' tape before it gets wrapped up inside the box to 'fair' the connection between the centerboard box and the bottom of the hull...

Wayne Jeffers
06-07-2002, 01:04 PM
What Barrett said.

Purpose is to minimize turbulence (and the resultant drag.)

BTW, some one-design class rules do not allow this.


[ 06-07-2002, 02:06 PM: Message edited by: Wayne Jeffers ]

Wiley Baggins
06-07-2002, 02:07 PM
I'll add my vote to those of Barret and Wayne. The 'glass tape looks to be functioning as a chafe guard.

06-11-2002, 12:40 AM
These are used to close the part of the centerboard slot which isn't full of centerboard. They prevent water from turbulent burbling up into the slot. Boat goes faster, they say.
Popular materials for this are rubber sheet and mylar/sailcloth.
If gofast matters, they're a good idea. If not, they're a maintenance headache.

06-11-2002, 09:28 AM
the boat goes faster AND stays drier, particularly when much of the board is up on a downwind run.

the FJ's and 420's I raced in college had these as a matter of necessity. a windy downwind leg with a torn gasket creates an impressive geyser and requires some handy bailing work by the crew.

fundamentally, they're just a strip of mylar sailcloth folded back over itself lengthwise, secured under a metal strip, with the whole deal recessed 1/8" or so into the hull. The forward end was usually tucked under a small strip of rubber (a fairing for the fairing). Because we carelessly dragged the boats up onto the floats at the end of each sailing day, they wore out/ripped and were replaced each season as a matter of routine, but if we'd bothered to be a bit more careful with them there's no reason why they shouldn't last much, much longer.

if you just want to throw your checkbook at the problem, call your local sunfish/laser/vanguard dealer and by a replacement kit. they usually include the screws even!!!

Ron Linton
06-12-2002, 10:58 AM
Thanks guys - no doubt I'll swing a flap of fg up inside the centerboard case on my Windward 24, but I don't believe I'll be reaching sailing speeds that will make turbulence up inside the case an issue. Thanks for the insights into racing issues.