[frers-list]Fairing keel and rudder
Courtney Thomas
frers-list@lists.frers33.com
Mon, 09 Dec 2013 11:13:36 -0500
On 12/7/2013 4:51 PM, ARTHUR KELLEY wrote:
> I made an unplanned stop at the boatyard today to check my cover and
> remembered this thread. Since we have two boats in the same yard, I
> figured I'd check. Again, this was unplanned, so I was alone and did
> not have a ruler or tape measure but used a sail tie to compare the
> foils, and came back and measured the sail tie. Trends good,
> accuracy, not so much.
>
> The keels seem pretty similar, both faired to about 1/8" (Boat A) or a
> bit less on Boat B and both keels approximately the same length
> (depth) below the bottom.
>
> The rudders were a completely different story. Boat B appears "stock"
> with a fairly thick, rounded trailing edge. There is a school of
> thought that suggests that the rounder edge reduces turbulence when
> turning or when the rudder is offset from centerline like when going
> upwind with some weather helm. Then again the thicker edge does
> create more turbulence when running straight with the rudder on
> centerline.
>
> The rudder on the Boat A had been faired to about 1/8", the same as
> the keel, but to achieve this the trailing edge had been extended by
> about 2 1/4" to 2 1/2". This also affected the roundness of the
> bottom of the rudder. Both rudders seem to be the same length.
> Measuring from the leading edge of the rudder just below where the
> notch for the skeg ends, and running parallel to the top edge of the
> rudder (see attachment), Boat A's rudder measured approximately 28
> 1/2" and Boat B approximately 26 1/4". Remember I am measuring to
> knots in a sail tie here! Both were about 60" long, top to bottom.
>
> I photographed both rudders, traced them in the computer, then
> overlaid the profiles. The diagram (attached) is perhaps not as
> smooth and clean as they could be but this should be sufficient to get
> the general concept - and generate discussion. I would need to
> re-photograph the keels, the perspective was different and the overlay
> just did not work.
>
> I have not spoken to the other owner yet about what he knows about any
> modifications to his foil(s), so am keeping the identities of the boat
> anonymous for now. He frequently beats me, but I don't think that's
> raw boat speed as much as he and his crew just being a bit better than
> we are.
>
> Joyce, if you come up with your diagrams I'd be happy to post them on
> the class site, perhaps in the FAQ section.
>
> If anyone else wants to photograph their rudder or keel I can try to
> add those to the comparison. The photo would have to be taken with
> the camera aligned approximately mid-point on the foil and
> perpendicular to it.
>
> These specifications probably should have been more closely regulated
> in the early days of the class, but for now perhaps we should
> understand what the fleet looks like and try to avoid too much further
> deviation. In my mind changing the location of lead would be against
> the one-design rules so Bill, I applaud you for planning ahead for the
> event that someone wants to bring the boat back into class specs.
>
> Regards,
> Art
>
> On Thu, Nov 28, 2013 at 09:25 AM, Scott Marino wrote:
>
> > Joyce,
>> Sounds like those pics might be a nice additions to the Frers website
>> for all to see.
>> Scott
>>
>> --------------------------------------------
>> On Wed, 11/27/13, Joyce Oberdorf wrote:
>>
>> Subject: Re: [frers-list]Fairing keel and rudder
>> To: frers-list@lists.frers33.com
>> Date: Wednesday, November 27, 2013, 12:48 PM
>> Bill--
>> Here is what I know. When I bought Checkmate,
>> eons ago, we looked at 4
>> Frers 33s Each one had a slightly different keel and rudder.
>> Wolverine had a
>> less deep keel-- but NOT the "shallow keel" version.
>> Impetuous had a deeper
>> keel, faired to a fine blade, as was the rudder.
>> We measured with calipers the thickness of the trailing
>> edges. ALL
>> DIFFERENT>
>> This is apparently not covered by class rules. At that
>> time (way back in
>> the 90s), Impetuous was one of the leading boats, and the
>> owner, Paul
>> Zabetakis, was class president at the time. And close by. So
>> we decided to
>> go with that. We extended the rudder about 3 includes
>> to fair it from about
>> 3/4 inch to a fine edge. Did the same to keel. We didn't
>> have templates. If
>> I can find the diagram of the two boats we measured (I
>> plotted the shapes on
>> graph paper, I'll copy scan and email.
>> Joyce
>> On 11/18/13 1:44 PM, "Bill Thompson" wrote:
>>
>>> Hi all,
>>>
>>> Have sanded d'Ad lib's hull - waterline and below -
>> back to the vinyl ester.
>>> Brutal work. The good news is, after 27 years, not a
>> single blister, soft spot
>>> or other imperfection. Washed and wetted down there is
>> no ripple of
>>> imperfection to be found in the reflection. Come
>> spring, sealant and 6 coats
>>> of inter protect before bottom paint should keep her
>> dry and healthy for a
>>> good long time. Pics avail. if anyone would like to
>> see.
>>>
>>> However, keel and rudder (which is still dry) are not
>> as fair, so I'm
>>> wondering if anyone has templates and/or methodology to
>> suggest, so I can
>>> bring them fair, prior to coating and finishing. All
>> help appreciated.
>>>
>>> Bill Thompson
>>> Montreal
>>> _______________________________________________
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>>> http://lists.frers33.com/mailman/listinfo/frers-list
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Art,
Sure would appreciate the specs on the keels. I was told on purchase
that mine had been modified by a previous owner but now am not so sure.
My main concern is regarding the keel depth and it's effect on boat
performance.
All thoughts and experience appreciated,
Courtney