Advice on Fibreglass boat building

HI,all great forum

I am considering the pro's and cons of trying to build a one off hull and deck for a 45 foot yacht. Yes I know it sounds mad, but I was thinking of having it first designed ( by a proper yacht designer ) to be suitable for simple one-off female mold construction, ie developed surfaces only.

I have a reasonable bit of experience in fibreglass work , mainly small projects ( RIB consoles, GRP shower enclosures etc. I am very competent in woodwork etc. I have made plugs etc

I know this type of question has been asked before and I apologise if I'm covering old ground here

I would prefer to build in GRP rather then steel as I have no metalworking skills and I perceive steel therefore to be more difficult. ( and require lots of heavy lifting gear etc.

Would people recommend one of the one-off composite constructions, or feel that the best way might be a basic solid hand layup for the hull and then a fairly simple deck design to eliminate too much mold making.

Is it all a bit impossible?, how long would people think it might take ( I can work on it full time and I have one other person to help ( not GRP skilled)

Would I be able to get out of it for about 50-75K $ in materials . Say the mold was melamine faced or similar, I'm not looking for really shiny results etc, just a good strong hull and deck ( deck would be cored or course)

Its only at the thinking stage, I have corresponded with some designers but only on a very basic level. I was thinking that the design has to be capable of simple layup. perhaps a bit too much layup to compensate for errors etc.

Would I be able to compete a hull and deck in say 2 years

Yes I know I get people saying don't do it etc, I appreciate that it might seem nuts. but I appreciate any knowledgeable input or personal experiences


Thanks in advance

 

Ah, another Irishman looking to escape. The part that worries me is not that you want to build a boat, thats a given for most in this forum, but that you are thinking about a Female mold for a one off. Unless you are planning to go into business, or sell the mold, it is more traditional to build a one off male mold then turn the boat over after the outside was complete.
That said; I'll go into my usual rant. Re-build!! don't build. There are so many strong beautiful hulls that can be bought very inexpensively in wood , GRP, Aluminum, or steel. Buy an old boat at salvage and gut it. You will save yourself 2 years in building and many thousands of dollars, and you will be helping to continue a life of a good boat. I have done both. I have built 4 boats from the ground up, and I am on my second restoration. I am a believer in restoring.

 

Some suggestions apart from DON'T DO IT.

Typically the hull of a sailing boat is one third of the total cost. I expect you will get the hull built for USD50k without too much penny pinching. That is for materials excluding the design cost. Maybe USD20k for a one-off design if you shop around. You then have to fit it out, rig it, power it and buy a few sails.

Depending on the quality of the design and the standard of build you may have a boat with resale value around half of what it cost to build. So the boat has to be kept for a long time. If your circumstances change and you do not have time to sail or family do not enjoy sailing then you have an expensive hole in the water gathering moss and aging fast.

With USD75k you could find a boat a little smaller than you would like to build that is in fair shape - say less than 10 years old.

Going the second hand route gets you into sailing quickly and you start to learn about the costs of keeping a boat. Maintenance is higher than a house and mooring fees are likely similar to rates. They demand a lot of time so they have to be a passion. If the passion wanes you will be able to sell the boat you buy for not much less than it cost if you look after it. Right now is a good time to buy second hand.

If you still want to build then you should look at flat-pack construction method as one option. They are certainly use this for catamarans up around the 40ft mark.

Rick W

 

I can understand the "dont do it". and while I didnt say much about my sailing background I have owned 9 boats in 19 years some sail some power and I have about 20,000 blue water sea miles under sail alone , including a transatlantic, so I know what it costs to run and keep a boat, ( and I know want I like and dislike), I ;ve sailed sloops, ketches, yawls, even a schooner. The passion is not likely to die anytime soon!

I am/have considered the "gut it" route but all that gets me is a standard boat with my fit out. But yes its an option I am considering, getting a suitable hull is a challange though, but youre right it does have many advantages, AN old HR 42 long kneel might be a useful start.

The reason why I'm considering a build is that (a) I want a particular type of boat based on my own requirements and after 19 years, and many sea miles and visiting dozens of boat shows and demonstrations. I can confidently say that I have been on almost all of the production yachts around ( above 40 feet) , including all the french ones ( of note, Alubat, Jeanneau, bene..amel , etc) all the german ones, all the swedish ones, the few UK ones, most of the US ones ( catalina,hunter,morris,hinckley, a huge proportion of the Taiwan/Chineese ones ( Hylas, Tayana, Taswell,Passport, etc)
and I find thah all of them are compromises that just dont suit. ( or there mad money). The sad thing is that production boats are all starting to look the same and are driven by marketing men & women etc ( dont get me started )

Secondly I have 2-3 years of time before I can do some decent continous sailing.

SO that brings me back to the original question. I am considering metal boats ( ie having the hull and deck built). but my preference is some form of composite construction , perhaps woodcored etc

I'm not worried about ultimately saving money ( more about getting better bang for my buck so to speak) , and I do like building things etc and I have the desire to do it. As to resale value, well it will be designed by a "brand name designer" and I beleive it will be competently built, and fully CE coded etc) , but I know that it will take a pasting ( mind you at the moment so is everthing)

As to the size, I'm 6'5", I need a decent size boat,!! My preference remains in teh 45-40 feet ( or just a shade under 15m, to keep med marina fees down).

Aanyone like to comment on the pro;s and cons of

(a) woodcore. ie cedar strip etc
(b) foam core
(c) solid layup
(d) male versus female molds The reason for considering female molds is that I preceive its easier to get a fair surface ( not neccessarly a glossy one), but thats open to argument

 

You have a good idea of where you would like to be. I can appreciate your disenchantment with stock yachts. Over 35ft they usually have a lot of expensive "goodies" that do not contribute to functionality.

As far as time goes I feel you will negotiate and to-and-fro with a designer for about 12 months to arrive at what you think you want. You will spend about 12 months building it unless you can devote to it full time. The build could be delayed if you do not have an enclosed shop with temperature control or you do not live in a location with stable weather. So lets say 18 months. You will then spend 12 months fitting it out to a useful seaworthy state. Hence 2 years would be a challenge for a boat of this size - more like 3 to 4 years.

You might benefit from developing a functional specification for the boat. Simple things to start with like 6.5ft miniumum headroom to more complex aspects that differentiate what you want from any existing stock yachts. Once you have this look around at stock yachts to see what comes closest. My view is that a hull and deck from a stock design represents good value. You can then do the fitout to your spec to get sailing without unnecessary trappings.

Even going into more detail on this thread about the good and the bad of designs you are familiar with might provoke more considered suggestions from others who have worked through the process. What comes closest to what you want and what problems do you see with it. This sort of thinking will help direct the designer if you go that route. The clearer you are on your requirements the less it will cost - providing they are practical of course.


Rick W

 

For any boatbuilding at the size you are talking about, in my opinion, one should always start with a male shape. The human eye can judge fairness of a male shape much much better than a female shape. This is true even with designs done on computers. In real life 3-D, the human eye can pick up anomalies on the surface that are very difficult or nearly impossible to detect in the computer. This is why most production boatbuilders start with a male form, be it a plug or an actual boat, and make female tooling from there. You are always closer to the mark on fairness with a male shape. And for one-off construction, female tooling is wasted money and effort. Think about it--you put money into tooling that you never see in the finished boat, and then you throw the tooling away. Stick with the male shapes.

As for construction, The fastest and cheapest way to build a boat is a multichine hullform built in plywood. Steel construction figures in pretty low here too. After that comes round bottom hullforms done in strip-planking in either wood or foam core with composite skins. Wood-epoxy molded plywood is a fairly expensive way to build a boat because of the labor involved in laying down all the veneer strips to build up hull thickness. Aluminum construction kind of varies all over the place--it can be inexpensive in a chined hullform, but aluminum itself is expensive (prices are always volatile) and good aluminum welders are a little harder to find.

Generally, I think you have to first figure out what kind of hullform you want--round-bottom or multichine (both have their advantages and are not necessarily better or worse based on performance--the just look different). If you choose multichine, that will tend you toward steel, aluminum or plywood construction. If round bottomed, you will likely go for stip planked wood or foam core construction. Round bottom in metal, particularly aluminum is possible, but builders really hate building round bottom metal boats. I have my opinions as to why, which might be worth a beer by the seaside someday. At this size, I think it would be unlikely that you would go with solid fiberglass as you get too many benefits from cored construction.

I hope that helps. If you would like to learn more about my designs, you can visit my website at www.sponbergyachtdesign.com.

Regards,

Eric

 

Thanks


I am leaning towards round hull forms, and there are a number of dutch builders who specialise in either aluminium or steel round bilge hulls.

As to developing overall specifications, I have done this and I have developed my perspectives and requirements, This forum is full of people expressing opinions on different feature sets, so i feel thats another days work.

I put up the comments on females molds becuase, I want to see if anyone had a perspective. I too , know that the end result will be a male mold for the reasons outlined. ( The pain of all that long boarding though!)

My current thinking is composite construction using wood core and epoxy over laminates.

One thing that seems to be the case is that while hulls can be easily done, deck construction seems to require more care and greater core thickness.

Any ideas on suitable male mold based deck constructions

thanks so far

 

My 37' design Saint Barbara is carbon fiber over Western Red Cedar strip planking. You can see her at:

http://www.sponbergyachtdesign.com/SaintBarbara.htm

Also, my design Bagatelle is fiberglass and mahogany veneer over Western Red Cedar strip planking. This is located:

http://www.sponbergyachtdesign.com/Bagatelle.htm

And my new design that I would love to have for myself, Eagle (Globetrotter 45) is intended for foam core strip planking with fiberglass skins:

http://www.sponbergyachtdesign.com/EagleNews.htm

There is no getting away from sanding in boatbuilding. Longboarding is easy compared to sanding a deck. There are so many more surfaces, corners, and details in a deck that you have to address. And consider that if you were to build a female mold for the deck first, you have to longboard and detail sand that first before you can do any molding. A part is only as good as the mold it comes from, so you have to really good on the mold. Again, all money and work put into a mold does NOT end up in the boat. With good boatbuilding techniques and proper use of peel play in molding, sanding is actually kept to a minimum. Do not be afraid of sanding. Even with aluminum construction, if you are going to have painted surfaces, you first have to fill and fair the hull and deck with fairing putty, and all that has to be longboarded and sanded. There is just no escaping it.

The thickness of the hull and deck laminates depend totally on the estimated loads and the arrangement of the interior structure. Panel laminates are determined by the load on one side, and the spacing of frames and bulkheads on the other. If you have widely spaced frames and bulkheads, the panel has to be thicker. If you have closely spaced frames and bulkheads, the panel can be much thinner. Since the hull and deck surfaces tend to make up about 2/3 to 3/4 of the total structural weight, the easiest way to make boats lighter is to add more internal structure. This is axiomatic in boat and ship building. The added weight of more structure is more than compensated by the reduction in weight of the skins. This works to a point--it is still possible to make the skins too thin.

To save construction time and to keep the hull open for outfit, it is always best to build the hull and deck more or less simultaneously side by side. This is how production builders do it, and it is easily done in a custom situation. You need the hull totally open to gain easy access with the built-in furniture pieces and equipment. So you leave the deck off while the hull is being built. But with the accuracy that we do have in computer aided design, no matter what material the boat is built from, the deck can be fabricated on the shop floor next to the hull. This makes building the deck eaiser because you don't have to keep climbing up onto the boat to put the deck together, and you can reach underneath the deck easily for installing deck hardware. When the hull and deck are close to completion each, they can be joined together for the final fit. Of course, you would do a preliminary fit before interior work started, so that you are assured early on in the process that they will go together without a hitch.

You mention professional builders, yet at the same time bemoan the idea of longboarding. Are you considering having the hull professionally built, and then you do the rest? If the builder does the hull, he can certainly do the deck. And sanding is a fact of life. If you don't like doing it, you can hire someone to do it for you.

I hope that helps.

Eric

 

Goboat,
Now that you explained yourself I can see that you have many good options, Since money isn't the deal breaker like it is for most of us. You should consider a number of good options

The first could be to find a European builder that you feel makes a good hull such as Beneteau, or Swan and negotiate with them to buy a hull and deck then you finish the build.

If you are still not happy with any production hull design Ron Holland is on that other Island to your right. He would be happy to design a hull to your specs, or charge you a reuse fee for a proven hull design. Then, if you are still hell bent to build your own, build the hard back and a one-off male mold, and the lay-up to his specifications. You will not go wrong, It's the way most of us amateurs would like to be able to build.

 

Depending on what you want out of the finished yacht, I can think of many existing designs that fit the bill, in regard to hull shape, volume, performance envelop, etc.

With this in mind you chould, for a surprisingly small amount of money, be able to find a sound hull, maybe with some serviceable equipment aboard and work from there.

I've done this on a number of occasions, where we get a production boat, based on the clients basic desires. The last was a solid hull, intended for serious cruising about 40' on deck. We found a Cabo Rico that had stuffed itself under a bridge during a hurricane and sank. We bought the wreck from the insurance company, after it had been dragged to shore with a front end loader. It was placed on a flatbed and hauled 150 miles back to my place.

The deck cap and interior liners were removed as was all the equipment, most of which was useless. A new wooden veneer over composite bulkhead (raised panels and all) interior was installed over the existing structural grid and a foam cored deck, quite different from the original arrangement designed and constructed. The completed hull was 6% lighter then the original. A new ketch rig was installed and the boat is currently still in service along the New Jersey coast. The total out lay was about 70% of a new yacht of similar appointments and equipment, plus it had the custom interior and deck structures, making her quite unique and well suited to the new owner's desires.

The owner was also able to participate in the process (I'm a firm believer in sweat equity), making design decisions and grinding 'glass with the rest of the crew.

If you want to build a 'glass hull, then I think foam core is the way to go. You'll build over a male mold, stitching foam panels down to a scrape wood frame work. Then sheath up the exterior laminates, flip and repeat on the inside. I don't think this is most economical way to get a boat of your size (for the home builder) but it is one of the easiest for the back yard lot in 'glass. Of course you could build single skin too.

 

Great feedback,
as to using Ron Holland, hes actually on the same island, ( he lives in Cork) and in fact I have met the great man. However the money isnt endless and a full custom design professionally built hull maybe a bit too expensive. Also Ron Holland has moved away from 40+ footers to bigger and better things!.

as to buying hulls and decks, no production builder will sell a hull and deck as they dont want a "unique" version floating around with a dubious history.

THanks for advice so far. As to longboarding, I am aware of the requirements , just wish it didnt have to be done and yes I may hire a willing young fella to do that. Actually I have a design for a power long boarder so it might give me the reason to build it.

as to foam core , I had been siding towards say cedar core, but could you reccomnend any online sources or books on foam core and whats the most common type of foam being used now.

Thanks

 

The best foam core that you can use, in my opinion, is CoreCell. It is available from SP Systems/Gurit:

http://www.gurit.com/sector_introduction.asp?section=0001000100220016&itemTitle=Core Materials

CoreCell is a styrene-acrylonitrile foam, or SAN for short. That means it is a linear polymer that will not shatter like cross-linked PVC foams such as Divinycell. It also comes in many different densities, which is very good. Finally, you can buy it in bead/cove strip planking. It was developed by Tom Johannsen of ATC Chemicals in Canada and New York. Tom used to be the US import agent for Airex many years ago, but that deal dried up, so he went on to develop CoreCell. CoreCell is very similar, maybe better, in structural performance to Airex with the added benefit of being available in the higher densities for a wide array of structural properties. Core strength and stiffness are directly proportional to density. Tom and his team also developed the strip-planking method of using CoreCell. If I were to build a one-off composite boat today, strip-planked CoreCell is far and away my preferred choice for its structural properties and ease of construction.

Since SP Systems/Gurit is now marketing CoreCell core, and they being centered on the Isle of Wight and you being in Ireland, you can probably find links through the website above for technical information on CoreCell strip planking close to you. Give them a call and ask for the local tech rep to give you the information you need. You can also try ATC Chemical to see what they may still have in the way of technical literature.

http://www.atc-fp.com/

Regards,

Eric

 

thanks very useful info

 

Another approach?

Down the street from me is a place called Bayview Edison. They take 3D models and mill out plugs with their 5 axis routing machines. I've seen 45' + powerboats built from this group. I used them for my hull plug on the Dart project. Now that plug is having a female mold built form it. I was very happy with their price and quality.

But for you.. They have a neat different service. They also offer routing out short run female molds. These molds can only be used to pull a handful of parts, but for a one off, I'm betting this would be just the ticket!

Here's a link to my Dart hull plug being created by Bayview :

http://www.leftcoast.biz/iWeb/Left_Coast/Tooling_the_Dart/Entries/2008/8/22_Its_not_all_bad...html

Hope this helps, or at least tossed another cat in the sack.

-jim lee

 

Jim Lee.

Mind telling me how much the moulds cost you?