the weight alone tells you it is a weak lumber as most ceders are. Port Orford cedar which is used in boat building is much heaver and strong and resists rot. The white cedars absorb water--not good. so you would need to encapsulate it in epoxy and hope there was not a small hole to let water in.
The site I gave you lists many woods--compare Alaskan Cedar to white cedar.
It is a question of how long do you want your boat to last. sell the logs keep some and cut into 1/2" T & G for interior panaling. it is great for that and beautiful either natural or stained.
White cedar in the application listed above (cored laminate) is perfectly acceptable. It's lightness is an advantage not a weakness and it's one of the best woods for it's intended use (in compression inside a sandwich). Read the full thread folks (I'm assuming), before casting a poor light on a material. Using Alaskan cedar in the same application would lead you to a boat that is 50% heavier. Port Orford cedar would present a similar issue if used as described above.
I think these so called surveyors should have to build boats for 20 or 30 years before they open their mouths.
And I think you should realize that locating a weak site on the internet does not qualify your opinion.
What Par says about the use of white cedar is clearly an opinion made of extended use of, and an understanding of, its potential use as a core material in cored laminates. One hacks undocumented observations based on some uncontrolled happenstance experiments, with an unrelated material, hardly qualifies as useful information.
The laboratory testing and subsequent use of these different materials is documented extensively and is available to you from many sources if you care to find them. White Cedar makes a good core for a certain type of construction and can be used to a satisfactory result under restrictions to weight and an acceptable tolerance to accidental damage.
It is not large boat planking material. If you don't understand the difference then you should not be forwarding an opinion.
Balsa's compressive strength is a fair degree better then the white cedar, but you can't strip plank balsa core, so in this regard the cedar wins.
Look, in a cored structure you need good compressive qualities, excellent glue acceptance properties and preferably light weight. This is why end grain balsa is in sandwich construction, because little can compare with it's compressive strength, light weight and glue acceptance.
I also read that article and wasn't especially impressed, in fact noted obvious flaws in logic and some their conclusions.
White cedar, white spruce and other light weight species are commonly employed in certain types of strip planking, particularly the high modulus end of the scale. You can save huge amounts of weight without compromising strength, but you do have to have a clue about the panel engineering involved or you're just blowing smoke.
Lets talk apples verses apples here. I can think of at least a half a dozen different forms for strip planking, likely a few more. Each is distinct and relies on different aspects of the shell construction elements to gain rigidity. For the most part these separate qualities aren't interchangeable with other methods, without a big penalty, which typically is excessive weight for a comparatively similar strength value.
-A bit faster variant is the bottom of the hull in strip plank/fiber and the sides in plywood where there is little compound. But requires more skill and good engineering where the strip and the plywood are joined. but out of subject here-
The wood is encapsulated in a good strong matrix fiber/epoxy where thickness of the epoxy is controlled by the fiber, plus the subsequent coats. Resistance to the water of the wood used has no importance, and the pseudo expert opinions I have read on the subject (including in the cited link, but not all is bad in this site.) come of very poor craftsmanship. All material badly worked lead to disaster. The europeans shipyards have produced thousands of balsa and foam cored boats without any problems; balsa is an excellent core, strong and long lasting.
In strip planking the core taking the longitudinal stresses, its better to get the highest inertia of the skin (ie thickness) possible to get the strongest lateral stiffness by the fibers, that means also that you'll always largely have enough wood, even of low modulus, to withstand these longitudinal stresses. Calculations show easily a 5 to 10 coefficient security. So heavy strong woods are useless in this application, except maybe a few strips at the keel for resistance to puncture and crushing.
And Par is right again, any good light wood is good for strip planks. I have used cheap Northern Pine carefully selected with excellent results. Strip wood/fibers/epoxy is my preferred method for one off boats, any shape possible, easy engineering, fast building, good price, excellent ratio weight/strength , and long lasting. What more is needed?
The cedar will represent very little of the total cost of the boat. Do not expect great savings.
This is why I stressed "White cedar makes a good core for a certain type of construction" and is not to be relied upon for true planking.
It is interesting to note that the suitability of many materials is subject, to a certain degree, on the scale of the application. For example: I might consider using White cedar for the core of a 30 to 50 ft Cat, but at a certain point ( and I certainly don't know where that point is without testing) I suspect the returns on the ease of construction would lose out to the extra weight required to get acceptable panel strengths.
An exaggerated example of the effect I am talking about would be in considering steel as a hull material; it is a foolish choice for a dinghy, but after 100 ft, it becomes one of only two sensible choices. (and before you start telling me there are wood and carbon and glass ships above a hundred feet...I know this...I said sensible)
One time...just for fun...a friend and I built a topmast for a traditional cutter with some leftover white cedar and some scrap carbon tow. . It had the carbon tow hidden on the inside ( where it really was not all that effective). We put an enormous topsail up on it in light airs and did quite well with it for a while...it took an amazing amount of punishment. Then an unexpected gust sent it in all directions in a dramatic cracking explosion of wood and carbon. FUN! ;?)
Can anybody point me in the direction of more information on the Lord method? I think I've got a good feel of it from reading Gerr, but would really like to see a couple of boats in the construction process.
The point of using the White Cedar is to use those resources that we already have. Anybody can build a boat and circumnavigate. Go buy a set of Wharram prints and get the checkbook out. But can you do it using materials you already have, or keep the total out of pocket expenses below a certain dollar threshold? What is the lowest dollar amount possible? $25,000? $10,000? $5,000?
Here is where I'm at:
I'm 90% certain I can build a circumnavigation ready cat for less than $25k. I'm 25% certain I can do it for less than $10,000. I don't think there is a 5% chance it can be done for less than $5,000, but boy would it ever be nice to pull off.
I need the input of this forum in order to pull it off though.
Yes, suitability of a material depends on the scale, the limits mot being very precise and depending on the requisites of the design, in plain English what are going to do with the boat, it depends also where are going to build the boat. I feel that exotic carbon nomex is not the best material for a local shipyard in Honduras.
If you're going to sail in the Antarctic in the middle of the growlers, metal is evident, but steel for a 36 feet cruising boat is not the best choice...
Personally, by my experience I think that:
-classic wood and variants like double planking is only for pros. Difficult because you have to find the best woods and nowadays it's an hard task. Engineering is well known but after 100 feet it becomes more and more difficult to have an acceptable stiffness. I have participated in the building of a 42m lobster fisher, and the keel gave me some headaches solved by a nailed-screwed laminated keel in iroko. It wasn't a boy game. It wasn't cheap. Can be done in Third World countries with skilled workers. It can give durable boats (not always the main goal in work boats), easy to repair.
-Plywood in all this variants (classic on frame, composite seams, tortured, ployed, cylinder mold) until about 60 feet in yachts, and 45 feet in work boats. In the smallest sizes, about 30 feet, if the design shapes limitations are accepted, is the almost best material for the home builder, if used with epoxy and fibers.
For the pro builder, with a well thought planning and clever methods, it permits to build excellent boats a very good price with a nice margin (I did it...). A french shipyard used plywood until 82 feet, the best known is Kriter V, the boat is 30 years old and as nice as new)
Using a crap plywood is the big common costly mistake, that gave bad reputation to the material, needs maintenance but can last very long, I know some of 50 years old in good shape.
-Strip Plank, as Par pointed there are variants, so I'll stay with 2, all with epoxy:
a-strip with diagonal veneer planking and sometimes framing, used until 120 feet. Good results but I feel that metal would be more cheaper in the biggest sizes.
b-Lord Method and variants as Durakore. My preferred method for small boats. I won't describe again the advantages but I forgot one; versatility. You can use it from a canoe to a 80 feet just adapting the engineering and permits the good use of a great variety of woods. Gives incredible strong hulls. Can be beaten only by high tech composites.
The best method for the homebuilder, almost fool proof, and, for a clever pro builder, combined with engineering and planning, an excellent method.
The common mistake is the use of too small planks making the method tedious with miles of seams to glue.
-Cold molded wood and variant constant camber. The epoxy glues revolutionized this method, with resorcinol it was a pain...Can get very nice boats but it's work consuming, long and tedious. Impossible for a pro builder to get good margins. Excellent for the patient and meticulous amateur who wants THE YACHT, for the front page of Wooden Boat and win contests (I'm joking). From the prame to 80 feet.
-Polyester, and all its numerous variants:
-Monolithic and sandwich in female mold: good for pros and open to the worst results using underpaid workers. That explain its huge success among serial shipyards. From the worst to the best, it can give excellent and durable boats. Not for home builder, unless he has a mold, but even then it's no worth the work, better to buy a good used boat. It's an industrial method.
-Monolithic, Cflex and sandwich on male mold: one of the most painstaking methods. Smell and itching. Not so fast: fairing is as long, and sometimes more long than laying...I have proofs, with ciphers for a 8.10m sail boat.
- A almost unknown variant of various names, Kelsall being the most promoted by this designer. Another name in France is placo plastic.
It consist of flat plates made on a table and joined in a female jib like the plywood stitch and glue. Layers are added to secure the plates and to get the needed thickness. Bulking mats, honeycombs, and sandwiches can be used.
The great advantage is the fairing and finishing already done at 90% on the table mold. The con is shapes limited by chines.
The method is excellent for a small pro builder in Third World countries who can make one off polyester boats without the great expense of female molds, or the pain of male molds. Low cost also. Results can be excellent.
Can be used by a homebuilder wanting absolutely polyester or having not access to epoxy and goods plywoods unless expensive importation and shipping. A situation lived here in Mexico.
Polyester has been used from almost 0 to 170 feet, the good range being until 80 feet. The big engineering problem of polyester/fiberglass is the flexibility -low modulus- which obliges to a strong frame. I have a very disgusting experience of a 40 meters mine hunter breaking its shafts because of the flexing of the hull (it has been solved expensively) and some big yachts like Vendredi 13 needed major work for stiffening.
Has been tried with total failure on 50 meters fishing boats.
Personally the styrene smell remaining years in some boats gives me seasickness. And mold and fuel oil stink and it's perfect...
High Tech composites. For the home builder in small boats I do not see truly the interest, you can get almost similar results with the wood composites at 1/2 of the price, 1/5 of the cost of tooling and 1/10 of the aspirin or paracetamol. Needs excellent engineering, and highly skilled workers. French Brittany has the garbage dumps filled of carbon and kevlar failures, although having some of the most qualified shipyards. So qualified that they work also for racing cars, aviation and space industries. You can imagine the technical level...
Made by highly qualified pros having the tooling is top of top, but that's playing in the major leagues for the first place. Thick wallet with strong money like Swiss francs needed, the cost can jump fast until 300 USD a pound, and more...The accounting money unit is million. There are maybe 10 countries in the world where you can find the people able to work with these composites.
For 0 to 120 feet. I speak from experience, I have worked in the field several years ago. And I do not feel qualified now at pro level...things change fast.
The amateur can play with RC boats or planes or small structures, not a 40 feet race boat, or he won't get the optimum.
Metal. I'll put steel and aluminium in the same bulk to simplify grossly.
The engineering is well documented, no problem, but it's not the optimal material for yachts under 60-80 feet.
-Aluminium from 0 to 350 feet (a big ferry trimaran of about 100 meters has been made) Pretty expensive but not so so so expensive. Great advantage do not rust. Big problem (solvable) electrolysis. Delicate to weld. Very easy to work, bend, cut etc.
-Steel from 45-50 feet in Yachts, 30 feet in work boats until 550 meters (1800 feet) the biggest tankers made.
Pretty cheap by pound in big ships (and there is not other choice...), but no so cheap in yachts. Great advantage very resistant but not as strong as believed. Big con: it rusts, and needs excellent protection and maintenance and too heavy for small boats.
Rather easy to weld. Very hard to work, bend, cut etc.
Domain of the pros from small to giant shipyards. An inconvenient almost never mentioned; noise. Noisy to make (hearing and sight impairing are professional diseases of metal workers), noisy boats which need a good phonic insulation, or become pains in the a...I've spent years in metal shipyards and I've sailed thousands of miles on metal boats, I know a lot about noisy metal, I can talk hours on the matter.
It seems that a lot of people in this forum are not aware of the cost and weight of the thermic/phonic insulation.
A good amateur, with metal working background, can get excellent results Good tooling investment mandatory. Metal can give very good cruising boats.
If it was me and I owned those trees and had your goals I would sell the lumber to buy more durable proven lumber and keep some for doing the interiors.
It's expensive to make a boat, tons of raw material and thousands of hours of work. Hardware is expensive.
One of the cheapest to build is this size is the 43 feets Hughes (an experienced multihull Naval Architect).
The price of the plans (dirty cheap for the quality, Hughes sells good detailed plans) is 3200 USD. You can ask to Hughes a list of materials and make a budget sheet.
Real weight about 3700-4000 kg...In my opinion not for a beginner builder. Its a second project. Multis are technically demanding, do not hope to use a 19 century mast in varnished pine or substandard materials.
Some think of a 40 feet Wharram cat (not so cheap). If you like crowded tunnels, it's a choice. Wharram navigated in the 50ties in this way with his harem (yes 2 girls) in a hippy way so promiscuity wasn't a problem, lucky guy.
Maybe you have not this point of view about sailing. These cats are largely outdated, compared to the Hughes it's like comparing a Ford T to a Ford Focus, but Wharram is an excellent advertiser able to sell refrigerators to Inuits during the polar winter. Better: he sells DREAMS. He sells sun, white beaches, soft breeze in the face, easy lives, freedom and piñas coladas to people having hard lives in some overcrowded city. I have tried several wharrams ...
25k dollars is very, very, very, extremely short. For any kind of circumnavigation boat, even the most low tech monohull using a telephone post as mast, galvanized rigging and cotton sails...
Have you a good experience of sailing and what that implies? Have you any experience of boat building?
Am I missing a more cost effective way to do the structure itself? I'd really like to leave the hulls bare and not glass them, but I don't think I'm gonna get that option.
I understand the high expense in regards to raw timbers. I was a builder for years before finishing up my degree and starting a career in "corporate america". What I don't have an ability to gauge is the expense of the glass work and hardware. I can do the glass work myself, but need a lesson in estimating the materials side of it. As for hardware, I have debated the pine mast, but most likely was leaning along the lines of buying a smaller sailboat this spring, sailing it all summer, and then gutting it using as much as possible on the cat. Why would or wouldn't this work?
As far as design and Wharram, I was just throwing a name out there in sarcastic jest. I'm new to the sailing world, but kinda chuckle when I see people buy into what he's selling. I'm not going to knock anybody that pulls off building one of his rigs, but they are not for me. Call me a sick man, but I like the design of the older British Cats. Prout, Catalac, Iroqouis. These boats were built less for flash and more for durability.
The biggest thing that I don't like about the newer designs is the wide beam. From my former construction background I understand the added stress of wide spans. I can't believe that we don't hear more stories of these 20'+ beams coming apart on home built rigs.
As for sailing and building a sailboat. Never sailed a day in my life. Love the water, have owned many powerboats. Never built a boat. Life long dream to build and then circumnavigate. Lost a couple of people close to me this past summer and decided that I was going to do this before something happens and I never get a chance.
Life is too short.
So there ya have it. That's why I'm here. I've never built a boat before, but the thought of it has engulfed me. Enlighten me on the junk boat build. Help me estimate my expenses. Dissect my design ideas. I'm not an expert. I'm just a guy that woke up at 3 am and decided that I was going to start checking things off my list before my time is up.
White Cedar vs ???????????
I have never built a large sailing Cat. I have never had as a goal to sail that Cat around the world. I have been on the ocean in heavy seas on a mono hull sail boat. Not fun. You said you will have family and friends with you. We lose a lot of boats off the Oreon coast in weather, most are mid size with knowledgable skippers.
The design of your boat is beyond my abilities. I could build a 40' x 16' according to plans and specifications, but would not create the specifications
for proper materals to make such a dangerous trip. I would not use materials that are very light, absorb water, and prone to quickly rot, and are not strong.
I am building a 30' x 9' Cat now out of wood and I always overbuild for strength but this is a power cat. I do not intend to be out of sight of land.
4,000 miles out in the Pacific I would want at least $10.000.00 worth of radios and navagation gear. I would want 1,000s of hours experience. I would want a $8,000.00 tent/life raft.
I do not risk my life in adventures I am unqualified to do. Please re-think your goal for the sake of your family. I am unable to offer you accurate advise.
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