To scarf or not to scarf

Discussion in 'Boat Design' started by lazerus, Nov 26, 2008.

  1. TeddyDiver
    Joined: Dec 2007
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    TeddyDiver Gollywobbler

    There's nothing wrong with pine especially when it's cheep:D
    I'm building with fir and got it allmost free (couple of salmons 22 pounds each vs half a mile 2''x5'')
     
  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    George Buehler's concepts are valid, though I don't buy into the execution and methods so much.

    I'm pretty familiar with George's building style, for this type of design and if solid lumber, the bottom would likely be file planked, possibly with an exterior sheathing of plywood.

    Yes, it would be stronger if scarfs were employed, but I don't think necessary on a triple planked build. Personally I wouldn't bother with the triple planking, just double it, maybe Ashcroft style, so both layers go down at the same time. Inner layer solid lumber, exterior layer ply if you like, though I see no advantage to this.

    Yes, buying studs from Lowes/Depot can save funds, but not as much as you think when you have to buy twice as much, cut around lots of defects, etc., just to accommodate the design principles. With a 35,000 pound boat and assuming you can build it for $10 dollars (wishful thinking, honestly) per pound, the math is pretty simple as to the actual costs of this yacht. At $1,000 a month budget, that's a 30 year project to pay off the materials (at 10 bucks a pound). Lets say you can build for an astounding $2 per pound. This is still about a 6 year effort to pay off materials.

    I think you could build a smaller Buehler design and still be comfortable. Again, the displacement of the boat can be directly related to the cost of the build. Maybe a "Hagar" (8,000 displacement), possibly a "Juno" (a lot of boat and about half of the displacement of the 42'er), maybe one of his "up graded" Juno's, which have different features, less deadrise and less displacement.

    I agree with Tad, there are literally thousands of boats just waiting for a new owner, some free. I would be hesitant about buying a Buehler design unless I knew the builder well and the build was completely documented. With the cut rate materials and round the corner methods, you just can't tell what they used or did without full build documentation.

    Lazerus, even if you do plan on lots of cruising, including a fair amount of trade wind runs, the vast majority of the actual sailing time will be in coastal efforts, where a higher SA/D would be welcome, even necessary. The most traveled cruiser will admit 90% of the time the boat is berthed or on a hook, with the remaining time divided up into 8% coastal hopping and 2% (or less) passage making.

    Trust me I fully understand the need to build. Would it be much different if you found a sound, but worn out 1960's 'glass cruiser, for next to nothing. Ripped off the deck, gutted the interior and re-did everything, new rig, interior, decking, cabin, etc. The boat wouldn't look like anything but you own creation. It would have a solid, 'glass hull that is much less prone to leaking, caulking, springing planks, etc. and the satisfaction of doing damn near everything (including spending weeks fairing and fixing the 'glass hull) yourself.

    I know of three 40'+ yachts in my area that could be had for less then $3,000. Okay, they have spent engines, need new sails, rigging a couple need masts and their interiors look like the Russian 3rd Army spent their last payday in there, but hay, what do you expect for 3 grand. Their hulls are sound, with minor damage, mostly cosmetic.
     
  3. Boston

    Boston Previous Member

    have you looked at dinghies :idea:

    just kidding
    ok well start collecting stuff then and stick it in storage
    ( Im buying white oak and storing it for now )
    Tad's salvage boat idea was a good one if not to repair
    then for stealing things like lead from
    B
     
  4. lazerus
    Joined: Oct 2008
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    lazerus Junior Member

    Are you sayng that it will cost$10 pler pound of dispaced water?
     
  5. TeddyDiver
    Joined: Dec 2007
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    TeddyDiver Gollywobbler

    That's about correct. Take a brand new boat closest to your project and reduce about 40% labour..
     
  6. lazerus
    Joined: Oct 2008
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    lazerus Junior Member

    No disrespect intended but after you get a set of his blueprints and you price things out as set out in his book (I have)you come up with a different figure.
     
  7. Boston

    Boston Previous Member

    if your talking Buehler's book on backyard boat building
    then your referring to seriously substandard materials friend
    he has some good ideas
    but
    there is a limit to what I trust my life to
     
  8. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    I costed out a Buehler "Archimedes" (43', 42,000 pounds displacement) a few years ago, using construction grade materials and I'd be happy to compare the materials lists, privately through email. I did it a few different ways, one an all plywood build and also a solid limber build was included.

    How much waste did you account for? Staging, cradle, templates, etc.? Fasteners, ballast, hardware, electrical systems, plumbing, other equipment, goo's, goop', fabrics and related supplies, shop supplies , engine, transmission, sails, etc.? How complete was your cost out?
     
  9. Ilan Voyager
    Joined: May 2004
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    Ilan Voyager Senior Member

    You're gentle Par, with very soft words, trying to explain that's not a good boat. As I'm not well educated, as I do not sell plans nor I have acquaintance with any naval architect of sailing monohulls, I'll give my opinion "sans ambages" (straight).

    It's overkill, heavy, surely expensive because 35000 pounds cost a lot and God, it's so old fashioned. It looks as an old De Knocker design in the fifties.

    Even the Legh II designed by Manuel de Campos for Vito Dumas in 1942 looked more modern!

    Vee shape, the best way to have a lot of wetted suface, and bad initial stability. Surely upwind in the breeze that heels nicely. Very useful to clean the deck.

    Barn door rudder with a lot of inclination and not separated from the keel. The downwind stability won't be the best quality of this boat. When I think that Herreshof tried separate rudders around 1880-1890 to see it again in 2008, I'm in admiration of the stubbornness of some designers. Even Laurent Gilles abandoned that kind of rudders in 1970...

    35000 pounds for a 42 footer and just 100 gallons of water...and a few drops of fuel. And less than 1000 sq feet to move all that. There is a problem; you can't use the engine except getting out and in the harbour, and there not enough water to cross the Atlantic as surely the journey will last more than 50 days...

    35000 pounds with such scantlings means a heavy rigging, and low ballast ratio. The stabily won't be famous...

    I can add more bad comments about the method of construction as naval engineer, but such scantling delirium gives me stomach aches.

    Let's compare with a "normal" scantling for a boat of this size in plywood; 18 mm underwater, 12 to 15 mm at the top sides, idem for the deck in a good BS 1088 plywood with a good pine structure. Less expensive than two MDO plus wood. Less work.

    Often I use the trick to use 6 mm (1/4 inch) or 9 mm (3/8 inch) plywood because it's a breeze to scarf them with a Scarffer form West System (70 bucks) attached to a good saw. Panels are light, bend nicely, do not spit the screws or nails brief it's easy for a lone man with only 2 hands and not as strong as a gorilla. Plus you can obtain a monocoque skin, and if you add composite joints at the chines it's practically unbreakable. Chines are always the weak point on classical chine building.

    Before beginning the construction, and with your low budget you should think twice. Do you need a truly a 42 footer? Do you want to start a such hyper heavy boat (and thus expensive even with cheap materials) you'll never finish? Even physically it will be very demanding. Even with **** materials, heavy boats cost a lot. The price of the raw materials of the hull is a small fraction of the total cost. Even the work, that you think free costs, and a lot! Years and years of hard work, on weekends, nights, and holidays, what will become the relationship with girl friend, spouse, children, parents, friends ?

    ****last addition****
    Par, you're wright again, refit a good glass hull is be a very good method. There is a lot of apparently rotten fiberglass sail and motor boats with sound, well made monolithic hulls. I'm rebuilding a 36 feet Cigarette for a dive shop. The monolithic fiberglass hull is good and straight, all the rest (plywood plus polyester resin) is rotten, they got the hull for free and they spent just 300 bucks, the price of the rent of the trailer...
     
  10. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Ilan, I see no need to piss people off, I'm quite adept at it with the other half, which is enough for me.

    I have my eyes on several 'glass yachts, all making great "platforms" for a complete redo. I'm a bit picky on the hull form and type, so I'll wait some more. I just wish a Cherubini 44 or 48 would turn up derelict, so I can grab it up. Unfortunately, they made so few of the 48's, all of which are still sailing, that I'll be near death when one finally does come up for less then 3/4 of a million.

    One thing I didn't mention and a point that has been hinted at, is the basic hull shell (planking and decking) accounts for about 8% of the build effort and costs on this particular yacht, even using budget materials.

    1,400 sq. ft. of planking stock, 40 sheets of plywood per layer, another 500 sq. ft. of decking material, assuming 20 or so 2x6 frames, another 500 linear ft. of 2 by stock, of course you can double this amount to cover the structural floors, 600' or so of 2x10 stock for the keel and deadwood. This is just the most basic of materials list. A pro could get by with 15% waste, but a backyard builder would do well to keep it under 30%.

    In the end, the project looks to be 100 sheets of assorted thickness plywood, several thousand linear ft. of assorted solid lumber, a couple of nice straight spruce trees for spars, then come the systems. Even going without an engine or any electronics, a fair bunch of money will get dumped into lighting, plumbing, rigging and a custom set of sails (wait till you get a quite on 1,000 sq, ft. of cloth).

    It's an ambitious project, but certainly doable by a willful and determined builder with some experience. Of course it's not a first build.

    About their sailing qualities, they're not as bad as you'd think. Anyone that could live with a Tahiti ketch could live with one of these. I've had the experience to sail a few different Buehler designs. They do seem tender initially, as he points out, but once the chine buries it stops and becomes a rock. A slow roll moment, gentle motion and yes you need a fair bit of wind to move them, all of which sounds very familiar to a Tahiti owner. In brisk winds, they can make a reasonably accounting for themselves, but the skipper must have had some sail plan changes as they're surely under powered. I don't think I've seen a Buehler design with a SA/D over 16, with most being 14 to 15 (this one is high 14's). Their high D/L makes for a comfortable ride in a confused sea. When being really pressed hard (read sailing in a half a gale) they drag a huge hole to windward. It's an amizingly deep one, that reminded me of a ride I had, on a last generation of the 12 meter AC yacht, which also pulled this type of huge hole.

    Some of his later sail designs showed some promise, such as Dragonfly. Now there's a yacht with some potential. It would be cheaper to build then the one above and a lot faster. It's D/L is around 180 and with it's narrow beam, she'd propel easily, with smaller rags. He never completed his, though I understand a few have been built. His is for sale if I remember correctly and he wants 15 grand for the 15+ year old project that's not completed, nor ever splashed. Of course if I were to build Dragonfly, I'd make substantial changes to the under body and certainly the scantlings. I'd divide the appendages and firm up the bilges, particularly aft at the very least. I'd also take the weight savings and toss it into the ballast/displacement ratio, making a stiffer yacht that could carry more area. At this point it's no longer a Buehler, but a whole new design.

    He's all but abandoned sail, now focusing on his successful "Duck" hitch.

    As for the looks of George's yachts, they are what there are, working boat ancestry yachts. They have springy sheers, massive cutwaters, flat sided houses, all pretty typical stuff for a look-a-like coal hauler converted to pleasure use. I have an affection for this style of yacht, though having owned them, don't want to any more.
     
  11. lazerus
    Joined: Oct 2008
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    lazerus Junior Member

    THE QUESTION WAS ON SCARFING SINCE ALL THAT HAPPENS WHEN i TALK ABOUT AND ASK FOR CONSTRUCTION ADVICE ON HOW TO BUILD IT I GET TORN DOWN FOR MY CHOICE OF DESIGN i WONT BE BACK.
     
  12. Tad
    Joined: Mar 2002
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    Tad Boat Designer

    Laz....

    Don't let life eat you man.....

    If you think the detractors are bad now, wait till you start building the boat! Guys will come by every day to tell you how you're doing it wrong.

    Don't listen, you don't even have to be polite, kick em out of the shop. Building a boat, any boat, is hard.....but people do it. It may be easier (I know it is for me) to treat the project as a journey rather than a destination. Set short-term goals every week or month. Don't bother setting a launch date, it's a long way out there. Then when people ask when you're going sailing, tell em, " when the boat's ready".
     
  13. Boston

    Boston Previous Member

    dont let it get to you Laz
    we are all just a bunch of yachtsmen
    each with his own tastes
    Ive taken my share of abuse round here
    water off a duck friend
    just let it role away
    B
     
  14. ancient kayaker
    Joined: Aug 2006
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    ancient kayaker aka Terry Haines

    If you have the time, strength, tools and skill, scarfing won't cost any more money. Can't remember where I read this but somewhere on this forum I would guess-

    "build the best boat you can"

    Looking at the pics, some places a scarf joint might not be worth the extra trouble, other places it might actually help get the ply go round the bend before you do. Scarf smart!

    Par, try as you might, you still managed to piss off Lazarus. It's a gift you have ...
     
    Last edited: Nov 30, 2008

  15. Ilan Voyager
    Joined: May 2004
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    Ilan Voyager Senior Member

    Scarfing?

    Definitely yes, at least for the last ply to be sure of the continuity of the surface (no cracking joints and other ugly things) and to have the insurance of the smooth transmission of the stresses.
    For the MDO in the middle layer, it's not mandatory as its role is similar to the foam of a sandwich: you can improve the quality of the joint, a good one has been described in this post. Inside, follow that says the designer.

    You have enough scarfs to make that a special tooling is valuable. A Scarffer will help because it makes good feathers, the most delicate part, so it's easier to finish the scarf. A very good table bench, strong and straight is mandatory.

    Par and I are too good guys; we have tried to warn you, as we know that you're embarking in a fateful project, specially with 500 USD/month to finance it. You are free to do what you want. But do not feel despised as that has never been our intention.

    Together we have a few dozens of years (for my part 7 years as naval carpenter and after 31 years as naval engineer for the French Navy, my own shipyard, plus consulting in composite structures for race boats) of professional boat building and surely we have seen, expertized and built more boats that many of the people coming at this forum. I'm beginning to know what's a boat or ship, what works, and the most important : what never do.

    I maintain that it's a bad boat, and if you like classical sailing boats you have Francois Sergent, a very nice man, Pierre Gutelle who made a very good book about sail boat design (you can find it in english worth the money), Dominique Presles, a specialist of the Colin Archer among the French architects, and a lot among the americains. Boats well and rationally designed, many beautiful, some truly astounding.

    I conclude that as naval engineer, thus highly qualified to speak about this topic, the scantlings are a total delirium, an absolute foolishness, and the quintessence of the waste of materials and work. Spend 35 bucks, buy the good book "Boat Strength" by Gerr, read it...you'll be like St Paul on the road to Damas.

    I won't enter in a discussion about the sailing qualities of this boat: to be short I'll say that 99 % of the earth, past and present production are better than this...I know that is your dream, nevertheless I hate to see someone run to the disaster while he can get better. That's all, folks.
     
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