Gonna Reinstall My Skeg/Rudder Flaps At Next Month' Haulout

Jun 21, 2007
2,118
Hunter Cherubini 36_80-82 Sausalito / San Francisco Bay
Hopefully someone will have the info. If not, I'll measure when the boat is hauled.

At my last haul-out four years ago, I removed the "flaps" that had been covering the hull/skeg to rudder joint area. Reason was that the plastic had become rigid and the flaps were permanently flared out at about a 30 degree angle. (They were probably 1980 original.) I simply removed the 4-5 screws holding each flap on, filled the holes with epoxy and then painted over with bottom paint. And the old flaps went promptly into the dumpster.

I am curious to try again with the original design. John Cherubini must have considered the flaps performance enhancing enough to incorporate them into the production specification.

I recall from posts many years ago that Ed Schenck (I think it was you, Ed) fabricated new flaps out of resin and fiberglass. Not sure that I have the skills/patience to go that route. So I am thinking that plastics have come a long way over the last decade or two. In particular, ski boot plastic bends and flexes like crazy under pretty significant stress, but always returns to it's formed shape.

Today I called TAP plastics and the store manager said that ski boot material is polyethylene. And he has it in stock in 1/8" sheet form. About $3.00 per ft2.

I am thinking that 1' x 2' is probably plenty for both sides, but would like confirmation before I buy. Otherwise I will measure when hauled out. The TAP plastic store is right on the route between home and haul-out location.

Here is the link to TAP Plastic's url:

http://www.tapplastics.com/product/plastics/cut_to_size_plastic/hypact_vhmw_polyethylene/527
 

Alctel

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Dec 13, 2013
264
Hunter 36 Victoria
Re: Gonna Reinstall My Skeg/Rudder Flaps At Next Month' Haul

Interested to see how this turns out! Mine still has the original flaps - if I can reach them I'll measure over the weekend, else I do it when yhe boat gets hauled out on Monday
 
Oct 20, 2011
127
Hunter 30 Green Bay
Re: Gonna Reinstall My Skeg/Rudder Flaps At Next Month' Haul

Mine, 1981 H30 doesn't have any. Are there supposed to these strips on, and where would I get more info?
 
Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
Re: Gonna Reinstall My Skeg/Rudder Flaps At Next Month' Haul

Rardi:

Have you called SBO to see if they have them? It may save some time and toil.
 
Jun 21, 2007
2,118
Hunter Cherubini 36_80-82 Sausalito / San Francisco Bay
Mine, 1981 H30 doesn't have any. Are there supposed to these strips on, and where would I get more info?
The "flap" topic has only come up few times over the seven years I have been participating on SBO. I'm pretty sure it was only the 36's and 37's that had them.
 
Jun 21, 2007
2,118
Hunter Cherubini 36_80-82 Sausalito / San Francisco Bay
Rardi:

Have you called SBO to see if they have them? It may save some time and toil.
Steve:) no, I haven't checked sbo. This would be an ultra-specialized part good for only a couple of hundred boats ever made - many of which probably had them removed long ago by previous owners. And my guess is that most current owners probably aren't even aware about them!
 
Jun 8, 2004
1,085
C&C Frigate 36 St. Margarets Bay, Nova Scotia
Hopefully someone will have the info. If not, I'll measure when the boat is hauled.


Today I called TAP plastics and the store manager said that ski boot material is polyethylene. And he has it in stock in 1/8" sheet form. About $3.00 per ft2.

I am thinking that 1' x 2' is probably plenty for both sides, but would like confirmation before I buy. Otherwise I will measure when hauled out. The TAP plastic store is right on the route between home and haul-out location.
Somewhere out in my messy garage I have a pair that I used for templates. I am not sure if the 36 & 37 used the same flaps? In any case, 1' x 2' of 1/8" poly should do it. It took me less that 1/2 hour to make new ones; as I recall I used a pair of Weiss sheet metal shears as 'scissors' and a leather hole-punch for the screw holes - my plastic was thin and easy to work so it was a lot faster than saw and drill press!
 
Jun 21, 2007
2,118
Hunter Cherubini 36_80-82 Sausalito / San Francisco Bay
Jim,

Don't spend any real time looking, but if you stumble upon your old flaps in your garage, it would be great if you could take a photograph of one and post it on the forum. Perhaps place a ruler next to it. Then from the shape, I can extrapolate all of the dimensions. But as I said don't spend any real time at this. Thanks.
 
May 27, 2004
2,059
Hunter 30_74-83 Ponce Inlet FL
Re: Gonna Reinstall My Skeg/Rudder Flaps At Next Month' Haul

As the original owner, I assure you the 30 had no flaps.
 
May 31, 2007
783
Hunter 37 cutter Blind River
Re: Gonna Reinstall My Skeg/Rudder Flaps At Next Month' Haul

I laid mine up on a flat surface using 2 layers of 1707 stitchmat. Can't remember if I used epoxy or poly resin but now I would recommend the epoxy as it has a higher stretch factor and they need to be quite flexible. I ended up having to grind them down considerably to get them to flex sufficiently. Seven years later, still going strong but in retrospect I think the polyethylene sheet would be the better choice of material and considerably less work.
I believe Ed S. filled the screw holes and filled the partial skeg inside, omitting completely the flaps, but he will likely chime in at some point.
 

Blaise

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Jan 22, 2008
359
Hunter 37-cutter Bradenton
Re: Gonna Reinstall My Skeg/Rudder Flaps At Next Month' Haul

I have my sailmaker make a new set for Midnight Sun about every five years. They don't do any good if they don't bend. Mine are made of pattern mylar covered on both sides with 10 oz dacron sailcloth. They are cheap, hold bottom paint great, last for years, and actually act as fairings.
 
Jun 8, 2004
1,085
C&C Frigate 36 St. Margarets Bay, Nova Scotia
I have my sailmaker make a new set for Midnight Sun about every five years. They don't do any good if they don't bend. Mine are made of pattern mylar covered on both sides with 10 oz dacron sailcloth. They are cheap, hold bottom paint great, last for years, and actually act as fairings.
That sounds like a really good solution. The 1/8" Poly ones do bend when the rudder pushes up against them, but the don't "wrap" on the opposite (leading edge) side of the rudder. Hydrodynamically, your mylar/dacron ones would work better.
 
Jun 8, 2004
1,085
C&C Frigate 36 St. Margarets Bay, Nova Scotia
Here you go
Not sure if its just the photos, but those do look a bit different than the H37C flaps - mine are arrow-straight on the forward edge. Overall dimensions are about the same, tho.
 

Blaise

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Jan 22, 2008
359
Hunter 37-cutter Bradenton
Re: Gonna Reinstall My Skeg/Rudder Flaps At Next Month' Haul

Jim,
They are correct. It looks like they curve because of the curature of the hull.
 
Jun 21, 2007
2,118
Hunter Cherubini 36_80-82 Sausalito / San Francisco Bay
Alctel,
Thanks for the photos with the tape measure on top. Perfect!
How's the haul out going!
 
Jun 21, 2007
2,118
Hunter Cherubini 36_80-82 Sausalito / San Francisco Bay
Blaise,

Can you describe with some more detail the sail cloth + mylar flap construction method?

I've got very heavy sail cloth pieces around plus west systems epoxy plus fiberglass resin, etc. For a diy attempt.

Thanks,

Rardi
 
Oct 27, 2011
154
Hunter 1980 Hunter 30 San Diego, Mission Bay
Re: Gonna Reinstall My Skeg/Rudder Flaps At Next Month' Haul

Rardi -
For my 505 racing dinghy, we make up flaps for the centerboard well consisting of two layers of heavy (3.5 oz?) Dacron, with Mylar in between. These are stitched together with Dacron thread. Can't recall the mil thickness of the mylar, but I'll bet your sailmaker could suggest something.
Best,
Gary
 
Jun 2, 2004
5,802
Hunter 37-cutter, '79 41 23' 30"N 82 33' 20"W--------Huron, OH
Re: Gonna Reinstall My Skeg/Rudder Flaps At Next Month' Haul

For several years my DIY flaps were made from heavy stair treads, the hard rubber type. I did finally remove them and filled the holes with epoxy mud. Early on I filled that space inside the boat. Those screws went into a void that always seemed like a weak area and prone to leaking. I shaped a piece of 2"x4" and glassed it down in there.
 

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Blaise

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Jan 22, 2008
359
Hunter 37-cutter Bradenton
Re: Gonna Reinstall My Skeg/Rudder Flaps At Next Month' Haul

My flaps were stiched along the edges and across the width several times. Get your sailmaker to do it unless you want to buy your wife a new sewing machine.