View Full Version : Deck Planking a Small Sailboat
11-29-2001, 08:08 PM
I'm building a Catbird 16. The plans call for decking with 1/2" ply covered with dynel and glass, but I would like to do sprung decking just because it looks so nice. Found a good supply of Eastern White Cedar for it. I need some advice on methodology. I see 3 choices:
1. Full planking with caulked seams. With a boat this small, the planks would only be about 1/2" thick by 1 1/2" wide, and I'm worried about enough thickness for caulking. Also, the ply might offer more stiffness than caulked decking.
2. Full planking as above, but edge-glued. Only 4 planks wide at the cockpit sides, about 3 feet of planking across the front deck. It would be screwed at 2 foot stations, but would it still want to move too much?
3. Layer of 1/4" ply on the deck with 1/4" thick deck planks epoxied to the ply and edge-glued.
Methods 2 and 3 could also have a layer of glass and epoxy on top. Any advice or recommendations??
11-29-2001, 08:40 PM
Ron I build,20 foot shark river dorys and use method three .I rip 3/4 mahogany into 1/4 in strips . Than cut a 1/8 in rabbet the width of my blade .after the deck is laid Ifill the rabbit with epoxy mixed with white pigment ,Sand the deck ,give it 2 coats of clear epoxy ,then several coats of varnish with uv filter . It makes a real nice looking deck.
11-29-2001, 09:22 PM
We just went through a similar discussion a couple weeks ago, Ron, and the concensus from the experienced people was that a true laid deck should be 7/8" or more, which is too much for a small boat.
The 1/4" ply with strips laminated on seems to be the most common solution.
11-30-2001, 05:40 AM
I have been pondering the same problem with my Nancys China (16'). But I wouldne trust 1/4 ply to keep 1/4 decking stable. To much chance for movement between the strips. Just my opinion. Please note this is my first boat, but I am a woodworker by trade.
11-30-2001, 07:12 AM
Hopefully I am sending a shot of one of my dorys this is my first try at this hope it works http://albums-photopoint.com/j/viewphoto?u=1523756&a=12334040&p=412699529&f=0
11-30-2001, 07:14 AM
well that didn't go to well did it
11-30-2001, 08:25 AM
Quarter inch ply rigidly (more or less) held in an arc is pretty stiff. But it doesn't keep the deck strips stable, the epoxy is supposed to keep the moisture changes down to the point that the changes in shape are sufficiently controlled. It's not perfect but it seems to work for the people who have tried it.
11-30-2001, 09:15 AM
I don't have any personal experience to offer but when ILYA racing scows were made of wood the deck was done per method 2 and then canvas covered. Boat sizes ranged from 16 foot to 38 foot.
I build a melonseed (small 13'sailboat ) with 1/2 quarter sawn cedar planking and it is caulked. Admittidly, the deck is 3/8 cedar and canvass, but I think you could bet away with 1/2 or 5/8 cedar decking if ti twere quartersawn. The folks who said you need min 7/8" deck are right...if you are looking for a perfectly watertight deck...ie a cruising boat. But I am assuming that if a few drop s come through your 16' boat it is no tradgedy and that primarliy the deck is there to keep you from being swamped. Given that, if you have good cedar and have you heart det on a laid deck...have at it. It might be worth tightening up the deck beam spacing some to help avoid the planks shifting against each other. BOL-rob
11-30-2001, 09:15 PM
Don't go there. Read the thread on decks in here a few weeks ago.
1. Your boat is too small to carry a planked deck. There are ways you can make it work (veneer plank over ply) but even then it will offend the trained eye. Maybe even the untrained eye will sense that something's not quite right. Putting a faux plank deck on a boat too small for it is like sticking plywood on your brick fireplace and painting it to look like marble.
2. There is likely a good reason why the designer specified a plywood dynel and epoxy deck. It won't leak and it will provide far more strength to the vessel's structure with far less weight. A planked deck will not provide sufficient rigidity unless the scantlings of the deck beam structure, the covering boards, clamps and shelves are built sufficiently large to carry a thick enough deck. Gaining sufficient structural strength in that fashion would produce a tremendous change in the weight distribution of the hull.
If you want to look salty, use the ply and dynel and epoxy deck and lay some nice accent trim in the waterways and down the centerline. Save your planked deck fantasies for a bigger boat.
12-01-2001, 07:39 AM
What Cleek said. You ever see one of those old VW Beetles with a Rolls Royce grill on the front?
12-02-2001, 06:41 AM
Thanks Bob, that answer clarifies that about my boat. I keep trying to turn my little plywood sloop into a Herrschoff Yacht instead of appreciating it for what it is.
12-02-2001, 03:01 PM
Wolfie... you can still turn your garage into Herreshoff's yard... just keep in mind that Herreshoff's canvassed their light boat decks back when, and would certainly have used dynel and epoxy over ply, had that been available in their time. What gives a boat the look you are shooting for is the quality of her fit and finish, appropriately done. The accummulation of attention to every detail produces in the end a whole that will indisputably say "quality!"
12-02-2001, 03:27 PM
The pictures of the Farne Islander, a 20' gaff rigged cutter designed by Iain Oughtred, it The Boatman that caused me to fall in love with the design showed a teak stripped deck. I thought it was beautiful but in the end I let the yahoos on this forum talk me out of making Prairie Islander that way. I was beginning to have second thoughts based on a test piece I made with 1/8" teak on 3/8" ply but they gave the the whack in the head I needed. Sure saved me a lot of work and who knows how many head aches in the future. Oh well. The painted dynel doesn't look all that bad...
12-03-2001, 05:38 AM
At the risk of incurring the wrath of the venerable Cleek, I think this bit about laid decks (teak or otherwise) offending the eye is a load of nonsense - to me, teak decks just look right and seem right on almost any wooden boat. Only my opinion, of course.
As to fitting, I would use to 3/8 (9mm) ply as a base, glue the strips down with epoxy but caulk with polysulphide. The 1/4 (6mm) ply I've used recently seemed to warp very easily and I wouldn't have trusted it for decking - but perhaps it was just a poor batch. Of course, going to 3/8 and adding the deck strips will increase the weight and this should be checked out with the designer before proceeding.
We're fortunate to have a number of excellent maritime museums where we can go Look at the small craft of the past . The museums are filled with decked small craft that never saw canvas .
Speaking from memory , the work boats I've seen are decked fore and aft with straight sided planking , while on some of the fancier pleasure craft the planks are shaped so the seams converge gracefully toward the bow . Even painted this construction adds another level of craft detail to the boat .
How to best install this is a seperate issue , but such decking can hardly be considered an affectation on small boats , if people want to take the trouble .On certian workboat reproductions I'd say it's the yacht canvas-like Dynel over ply that would strike the false note estheticly , tho I understand the reasons for doing it .As an aside ,I thought the photo of the Oughtred boat on the former thread showed decking run fore and aft, tho the discussion focused on sprung decking .
Norm I can't say they told you wrong about the sprung decking . Your boat's 20 ft. and the smallest boat with a sprung deck I immediately see in my library is a Great South Bay Catboat 21 foot 5in. long which is at Mystic Seaport .She was built around 1890 in Pachogue Long Island by "a notable builder of raceing sailboats ". We can assume that She at least did not offend the trained eye .
There's a black and white photo of the boat in Bray's "Watercraft" (which contains most of the Mystic collection ).The deck is varnished and looks in decent shape .White Pine or cedar I guess . The lines of a similar boat by the same builder are on the same page . These include a fully rendered deck plan , presumeably because the design and detailing were considered top notch .I scaled the reduced drawing as best I could .The planks are about an inch wide . Mystic sells the plans .
Whatever the deck's made of , this lean and mean Cat is one of the many Mystic boats that I covet .I believe the apprenticshop built a Ducker this summer .The plans call for 1/2 in. pine or cedar plank with beams I scale 8 in. O.C. Anyone know how they installed it ?
[This message has been edited by Will (edited 12-03-2001).]
12-03-2001, 07:36 PM
The boats Will refers to were built by Gil Smith and have sprung white cedar decks. These are lightly built gorgeous and elegant looking boats, but they are also daysailor racers. A leaky deck on a daysailor is much different than a leaky deck on a cabin boat with an interior that you would like to keep dry. I've seen sprung and straight laid decks as thin as 1/2" and they can look very nice if all the proportions are right. But any thin laid deck that I've seen where they were concerned about leaks had canvas on it. The above comments pertain to traditional laid decks. Laying thin strips over ply makes a fine deck. This is strictly personal preferance and if that is the look you want go for it, after all it's your boat and it should make you happy.
[This message has been edited by holzbt (edited 12-03-2001).]
12-03-2001, 09:58 PM
Will, the Oughtred boat in the previous thread is Eun Mara #1, and she's decked with 1/4" ply overlaid with 1/4" iroko strips and black goo in the "seams."
Sure looks good, though.
12-04-2001, 06:48 AM
Cleek, You and I need to call a meeting of the Good Taste in Decking Committee and see if we can find a way to stop this before it's too late.
12-04-2001, 10:16 AM
Here is a small boat to see with laid deck.
12-04-2001, 01:09 PM
Thfin... Thanks for that link!
I think I'm getting "teak envy"... Care to translate the text for us? http://media5.hypernet.com/~dick/ubb/smile.gif
[This message has been edited by Art Read (edited 12-04-2001).]
Watch out your boat could end up looking like this . The scanning process was not kind to the really nice drawing .
Esthetic judgements are so subjective .I saw plenty of Herreshoff 12 .5's , Fish Class and others cruiseing with my parents in the area from Fishers Island Sound to Buzzards Bay when I was young , so I expect these little yachts ( and the Haven ) to have the canvas or frp cover with accent trim ,exactly as Bob describes . It's an elegant look .If I'd grown up in Finland surrounded by a different tradition , I would have different expectations .I think the Haven is a special case for North american sailors at least . She's so closely tied to a preexisting Yachting icon that we know exactly what she "should " look like .
[This message has been edited by Will (edited 12-07-2001).]
12-04-2001, 11:44 PM
well I am going to make another try at posting a picture
12-04-2001, 11:46 PM
Well back to the drawing board
12-04-2001, 11:53 PM
ok one more time
12-04-2001, 11:55 PM
O THE HELL WITH IT I NEED A BEER .Ill try tomorow
12-05-2001, 06:26 AM
In the text it gives some historical background on the Haven 12 1/2. Nothing you couldn't read at the haven builders web site. This is a boat built in Finland by professionals. The deck is Oregonpine, mast is spruce and planking pine.That's what i call them. Actual spiecies you can find here.
12-05-2001, 10:05 AM
Oh great. Back on the fence again. And just when I was seriously considering canvas....
12-05-2001, 11:28 AM
LOL! I know how you feel, KW...
12-05-2001, 08:47 PM
[This message has been edited by videoguy (edited 12-05-2001).]
[This message has been edited by videoguy (edited 12-05-2001).]
12-06-2001, 12:50 AM
I DID IT WOW AND IT ONLY TOOK 3 DAYS!
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