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 Building the main hull.

 

After building and finishing the two floats, now it's the turn for the main hull. Please click on the images to open an extensive photo gallery of the various stages in the building process.

Beam Bulkheads

Beam Bulkheads: Before setting up the main hull, and while still having the room, I first made the beam bulkheads as these requires a special construction for the folding mechanism. A rather big laminating job with vacuum bagging. The first attempt is a bit disappointing, with epoxy everywhere, not only on the part, but also everywhere else. Because of a too sharp edge on the molded flange I pulled a big hole in the underside of the vacuum bag. Getting a wet vacuum bag airtight again is quite a job. While the resin clock continued it ended in a big mess. I left the workshop in my underpants, and with epoxy in my hair (it's shorter now). Now I know again why I dislike vacuum bagging and like the vacuum infusion so much. However, vacuum bagging is the way to go for this complicated laminating job. Or just hand-lay-up. But once used to the quality by a vacuum treatment, it's hard to be content with anything less. I am very comfortable using it. Starboard hull halve setupAt the end, after eight vacuum bags, it's becoming more of a routine with less mess and better vacuum bags. Practice, practice ..........

Setup first main hull half: This is one of these memorable stages. Not only the "real boatbuilding" work,  at least the fun part has just begun in this stage, but more memorable is the fact that the hull fits in my small workshop as I had thought to myself. It's a close fitting and a relief at the same time. I've started with the starboard side of the main hull as the geometry of this hull half fits better in my workshop.

I knew before that the height of the workshop is not enough to join the two main hull halves, so the planning is to make the second hull half and the joining to a complete boat in a bigger workshop somewhere else (still to find that place). This will be temporary and the completing of the boat will be again in my garage.

Layup dry fabrics and infusion

Layup dry laminate and infusion. The bag was perfect, the vacuum was almost perfect, however after the vacuum was on, I discovered I had a batch of wrong tubes. They look the same as I've had before, but these ones were pressed together and useless for the infusion job. Very disappointing. As infusion was planned for the next day (Monday, and with an announcement on the F-boat forum for a live show on the webcam)) a quick ride to fellow builder Bert Hofman brought the solution as he had enough tubes to help me out. It was late Sunday evening (or better said Monday morning very early) when all tubes were replaced by the good ones.

Infusion animation

Below the video (14,6Mb) and at the right the moving animation (1 Mb) of the infusion simulation.

  14,6 Mb video of the infusion of the main hull half

Lower folding strut anchors

Beam bulkheads and folding system setup : Making and positioning the carbon lower folding strut anchors turned out to be a tough job. I've had some worries because they are such an important structural part of the boat. The first two attempts were a bit disappointing but finally I developed the right method to wrap the carbon around the anchors blanks.

The building project until now was mainly a matter of forming foam into hulls, laminating (ok, better said infusing) and gluing bulkheads into position. It gave me the feeling of putting a boat together, but not constructing something. However, mounting the beam bulkheads and lower hull strut anchors with the accompanying reinforcements is much different from that and gave me the feeling of a constructing work. I was already impressed by the design drawings and engineering quality of Ian Farrier and the way these elements are being constructed is more than an confirmation of that.

Making of the daggerboardcaseDaggerboard case: The daggerboard case is made of marine plywood and I discovered the hard way (at least after two failed vacuum bags) that the porosity of the plywood makes it impossible to make an airtight seal with sealant tape onto the wood. Something to remember for all wood builders. The vacuum infusion was done with two bags, one for the infusion and one for the vacuum integrity. A stopgap and not something to copy !

Bulkheads and cockpit area

Bulkheads and cockpit area.
The finishing of this first main hull half with all the structural bulkheads and the making of the cockpit coaming, emergency escape hatch and the safety compartment.

On the left a video of the infusion of the escape hatch coaming.

UnmoldingUnmolding the starboard main hull half: This went on quite straight forward. Turning the hull with the four tackles was exciting and she went over with literally just a couple of millimeters to spare Most of the work was cleaning up the mess and to find a new place for all the stuff that I still don't want to throw away. The half hull is remarkable stiff and instead of starting the other hull half I decided to start with some more interior work as access to the hull is great in this stage. However, life would be easier if I knew what  do with the interior ..... decisions, decisions .........

Click for extensive photo gallery interior parts starboard side.

Interior layout: I finally decided about the layout of the interior. The biggest change compared to the standard aft cabin layout is the galley on starboard instead of port. Main reason for this is that I still like "the office" on board, which lead to a rather conventional layout, in particular in combination with a quarter berth. Because of the galley on starboard the settee in front of this is now shorter, but still useable as a (sea) bunk with the feet through an opening in the cabin bulkhead. Above that the diesel oven is situated. Galley top can be extended by folding down the backside of the settee back. The dinette is now two meters wide and can be converted into a large spare double bunk. Also the shower is a little wider. Without rebuilding the interior this can accommodate six (with table down eight and with spare bunks in the floats even ten) Cooking is on a ceramic diesel stove and in addition to this a fully gimbaled single cylinder burner, positioned in a dedicated housing and well ventilated outside.

Of course the interior question is a matter of personal taste. I think this is a good sea going layout and at least for now this design gives me some peace of mind.

Systems: Click on the colored system items in the layout drawing below to open a principle sketch about the subject. I will add more as progress allows.

Diesel fuel system Diesel fuel system Holding tank Wallas stove Wallas oven Cylinder burner

 

Making of carbon bobstay anchor

Carbon bobstay anchor: Some time ago I had a look on the composite department of Stork Aerospace and there I learned that they put a lot of effort in saving weight at the ends of airplanes and wings. Not a surprise of course but this reminded me of the quite heavy bobstay anchor in the bow of the F39. In spite of the fact that I prepared the piece of stainless steel to fasten into the bow, I decided to make a much lighter carbon one, almost in the same way as the carbon chainplates.

 

Moving to another workshopMoving to another workshop: Quite unexpected and totally on the spur of the moment we bought a new house ..... Sometimes that one in a lifetime moment comes along, in our case a water villa with a jetty large enough for mooring our F-39 trimaran. So, the other "dream" we had, living in a house near the water, has become a reality now and we will move to our new place by the end of this year (2009).  Which means I have to give up the workshop at home and move the boatbuilding project to the workshop of our company. This of course is a temporal solution with the necessity of getting in a hurry. This means from now on I will focus on finishing the F39 on the outside and get her in the water to tie her up along the jetty of our new home. Further work on interior, hardware and rigging will be delayed till she is at home again.

Planking the second main hull half.

Setup of the second main hull half. Again a fun part to do. Working in the new workshop looks to be much faster due to more space, better equipment, less distraction and less socializing.

And now there are a lot of critical observers (i.e. colleagues). No doubt they will inspect the work on Monday morning to discuss the working rate of their "boss" ..........

 

Vertical foam stripping.Boatbuilding again. Fitting out the new workshop turned out to be much more time consuming than anticipated. But now everything is in accordance with my wishes and this weekend I had the feeling to continue the boatbuilding again instead of all kind of other things, like organizing and cleaning up too much company materials, dragging along too heavy girders, hoisting and mounting too heavy winches, organizing and connecting too much electrical wires, building and pulling down again an incomplete scaffolding, which despite some missing components was strong enough to hold up the main hull half for a while, which by the way wasn't necessary if I had done the electrical winches first, etc.

Vacuum infusion of second main hull half: The handling of all the glass and vacuum materials is now much more convenient in this spacious workshop. However, in my enthusiasm I forgot to add some reinforcements in the window area and the area of the anchor locker. While writing this, the inside of the hull has been covered with the vacuum materials except the vacuum bag. Next weekend I have to fix that .......

Vacuum infusion of the second main hull halfOn one of the hottest days of the year (Saturday July 11 2010) the vacuum infusion of the second main hull half went flawlessly. I few hours before I was desperate not being able to find a big leakage in the vacuum bag. At first I thought having found the culprit, a forgotten connection of a vacuum line. But after I repaired that nothing changed.  To be able to hear better, I put the vacuum pump outside the building, however I knew that the leak was probably too big to be able to hear. I spent the whole Friday evening and Saturday morning on finding the leak. All kinds of scenarios went through my mind, including the worst, a poreus or a punctured hull. Just before I thought I was getting crazy, I noticed the cleaning lady who was still in the building on this Saturday morning. Knowing that women are much more patient, I asked here to help me finding the leak.  After 5 min (!?) she found a small leak in the bag. Unfortunately nothing changed when I closed it with a piece of tacky tape. Some minutes later she found the real wrongdoer, a big square in the bag, hidden in a pleat. She made my day! Thanks Angela! Now, I got some vacuum and the rest of the leakages were easy to hear and I even finished with a perfect bag.

The drop test (vacuum pump off) resulted in a not worth mentioning loss of vacuum. Room temperature was 32º Celcius and so was the resin. Just perfect for a fast infusion. Click on the above picture for the photo galery.

Alternative lampholderPort side folding system setup and beam bulkheads: When working on the starboard half I made all the carbon lower folding strut anchors, but not the complete anchor assembly for this port side. So, before putting in these carbon anchors, I first had to do some unfinished business on the carbon anchors. Cook them in the oven (this time not the one in the kitchen) and making the total anchor assembly.

Maybe it looks like I always have the things under control. But that is only apparent and silly mistakes are indeed made. After I freed the two carbon anchor assemblies from their vacuum bag and was preparing to mount the assembly in the hull, I discovered that the base plate was shorter than the anchor….. F**###(censored) In a fit of madness I had the base plate mounted in the wrong direction. Itself is not so bad were it not that all the UD fibers are now running in the wrong direction. Too bad of all the beautiful laminate work (and a waste of three days).

There is a lot of laminating work to do around the beam bulkheads with up to 20 layers of UD fabric in some areas. This construction looks to be real solid and bullet proof. As the lamination and bond to surrounding areas is critical I try to be very meticulous in this area.

Starboard meets PortA milestone, Starboard meets port: Here some photo's of the joining of the two main hull halves. Overall the hull halves fit very well together without noticeable misalignment. On Menno's Blog (Dutch F22 boat builder) I saw he used the two top battens to align both hull halves. Great idea (thanks Menno) because these battens make the use of clamps possible, which is much easier than bungling small wood pieces and screws.

I made the second (Port) main hull half a little longer in the stern. This was not possible in my previous workshop due to the lack of space. After joining the two halves I decided to make an extension to the Starboard half to make both hull halves the same length. I don't know yet if I will make the hull one feet longer, but doing this now in this stage is quite easy and I can always decide afterwards to cut it off.

Click for photo gallery.More bulkheads and details in the port side half: I made all the other bulkheads in this port side after the joining of both hull halves as aligning is much more easier this way. In the bow area I made the preparations for a second carbon chainplate. This is placed at the front of the anchor well and is intended for a heavy weather jib or storm jib. Since this is not a design feature, I've created my own solution. All the "thinking" about the cockpit coaming and shelves in the cockpit area has been done in the starboard half, so copying this to the port side was now done in just one weekend. For now the inside parts of the mainhull are finished and next is removing the frames and turning the hull upside down.

Freed from the mold framesFreed from the mold frames: A milestone again. A long weekend of preparations with among other things unscrewing 7500! screws. The big event, hoisting the hull and turning it upside down, was done in the next weekend. I like to do this on my own, without onlookers, no hurry, good thinking and easy going. The hull is now ready for further work on the outside.

Click for image gallery External laminate from gunwale to keel: Before laying up the external laminate, various "small" other jobs has to be done . Every time it is amazing how a relatively small job takes much more time than expected. For example the beam recess on the outside of the beam bulkhead. For cutting this recess area to size and removing superfluous foam hull parts I needed all the cutting and sanding tools I have, jig saw, reciprocal saw, multicutter tool, dremel tool, powerfile, belt sander, angle grinder, powerplane and the handtools like chisels, grater, hammer, file, multiknife, sandpaper, etc. and this all within 5 square ft . The four beam recesses took me two days with a lot of itch (from the glass dust) as a result. Then some foam fill pieces, which took another whole day. Everything is taking at least three times longer then expected .....

I made a little change in the lay-up schedule of the external laminate in the bottom of the hull. The plans specify an extra glass 0/90 layer in the bottom of the hull, for abrasion purposes and also for the balance between the 0º direction of the fibers inside and outside. As an alternative I've used a 45/45 Aramide (Kevlar) layer as the abrasion qualities of this type of material is superior compared to glass. The topside of the Aramide fabric is covered with a thin CSM layer, so the outside surface is glass and not Aramide. To compensate for 0º direction strength I've also added a line of glass UD in the opposite position of the internal UD layers. All in all a little heavier than specified, but good for peace of mind ....

Click for image galleryBow pole: At first I thought of making the carbon bow pole by myself, also as a kind of exercise for making the carbon mast and boom in future. But for practical reasons I decided to buy a custom made bow pole, to save on time and to have a look in the kitchen of a professional carbon mast maker. Thomas Whilkes of Ceilidh Composite Technologies (www.carbonmasts.com), the maker of the carbon bow pole, was so kind to discuss some ins and outs with me about making a carbon mast and the ideas I have to do this by myself.

The bow pole has been made in a female mould with carbon pre-pegs. The only thing I still have to do is making the attachment points for screacher and spinnaker. The bow pole is retractable and slides through a bow pole tube. To make the bow pole tube I thought I needed the bow pole as a mould, but in hindsight it was not necessary to buy the bow pole in this stage, as the outside diameter is exact the same as a 125mm pvc drain pipe. So, instead of the carbon tube I used a pvc drain pipe as a mould for the bow pole tube. With 7 layers of wallpaper I increased the diameter to 128mm for the easy gliding of the bow pole. The mould is finished with two layers of plastic film and a Teflon coat between the films to be able to release the glassfibre bow pole tube from the mould.

In the mean time I'm playing with the RTM-Worx software, on the one side to make the 3D model (that's fun) and on the other hand filling the model with material qualities like resin viscosity and fabric permeability (that's just a puzzle to translate in a lot of data)

Click for simulation and image galeryControlled Vacuum Infusion of mainhull bottom: I can say I now have a lot of experience with making airtight vacuum bags. As a matter of fact, within this project this is big hull vacuum bag number 9 and I thought it would be a piece of cake. After all, it is not just a vulnerable foam hull but a foam hull with an airtight internal laminate. And the joins of the Port and Starboard halves are covered with a glass tape. So no worries about air tightness. I thought ........

Unfortunately this assumption proofed to be very wrong. I did some stupid things, as using too long temporary screws here and here. This area was also not air tight. Further more it seems there were air channels in the UD fibers in the forward beam bulkhead flanges. In short, it became a headache vacuum bag, in fact the worse one I've ever made and it took much too much time to get it right. As the infusion of the hull was planned and I had appointments with some helpers I worked a continues 40 hours to get it right, but unfortunately the bag was not good enough to start the infusion. A disappointment for everyone and I had to cancel the event.

After some more changes in the bag and improvements of the hull integrity two weeks later it had to happen. Despite the fact the vacuum bag was still not perfect the infusion started at 3.00 PM in the afternoon. There were a few precautions taken to be able to solve possible problems during the infusion and this has worked out satisfactorily. Only the end counts and despite the troublesome preparations it was again a success, a big relief and another milestone in the project. After a evening and night watch during the cure of the resin I went home at 5.00 AM the next morning, tired but with a good and happy feeling.

 

On the left the video of the infusion.

Click for photo galery."Upside down" interior work: While the hull is still in an upside down position it is a convenient time to make the fillets that supports the horizontal parts like the cabin floor, settees and chart table.

Looking for a material that is able to follow the hull shape and in the same time remains horizontal I found Styrodur insulation foam to be the suitable material. All positions are marked with a laser and the mold is formed by the Styrodur which is supported by temporary pieces of wood. Because of the light weight of the Styrodur it is easy to fix with a 3M glue spray.

Click for image galeryTurning the hull upright: Turning the main hull upright is once again a milestone in the project after which a new phase in the build starts. Farewell strong back, the base construction on which all the hulls has been build, is now demounted in little pieces and removed to the dumpster. With my four electrical winches under the roof of the workshop, the actual turning went flawlessly. Of course I did it alone again and to continue to fully concentrate without prying eyes of others. With some extra ropes and the back-up of the workshop crane I took enough safety precautions to avoid any risks.

For the support of the hull in the next phase of the build I've build two mobile boat stands. For the subsequent assembly of the mainhull and the two floats the boat have to be more or less moveable without too much of a hassle. I used the hull as the mold for the two boat stands.

Click for photo galeryPreparations for the deck laminate: Now is the time to think very seriously about the deck lay-out. During the whole build I have been pondering with a few different options about rigging and hardware.

A deck stepped boom resolves the problem caused by lines (reefing lines, outhaul, mainsheet) coming from the boom and interfere with mast rotation. I made a mock-up to see how big of a problem this is and also studied a lot of photo's of the big 60' Orma Tri's. My conclusion is that it is not worth the extra trouble and the interference with mast rotation can be minimized by making the line exit in the boom a little more aft of the mast. So the boom will be mounted to the mast "the normal way" with the advantage that the boom induces the mast rotation.

I can see the advantages of the self tacking jib. However, there are some complications. The track crossing the daggerboardcase interferes with the daggerboard and the length of the track is limited by the folding movement of the beam. Nevertheless (I'm getting older and looking for more sailing comfort) I have decided to go for the self tacking jib and I assume that I am able to resolve this in the finishing phase of the build.

Furthermore I decided to make a curved track for the mainsail sheet traveler. Probably the traveler will be extended to the beams, but this is also of later concern. The mainsail sheet goes to the winch on the port side of the cabin roof.

And finally I have designed a plan to organize all running rigging from mast to the winches on the cabin roof.  With the above starting points and the running rigging plan I am now able to put in all high density foam inserts in all these places where hardware will be bolted down.

Click to open photo galeryCabin windows: The design calls for screwed down windows, but I don't like that solution. Instead I want to glue them in a rabbet. The outside of the window is then about flush with the outside of the hull. Determining the size of the intended windows, also a little different from plans, was a challenge to get it right. Finally I found out that I get the best appearance when the length halfway the height of the window is about the same for all three windows. The intended glazing material is still under consideration. The choices are polycarbonate, acrylic or tempered glass. The windows are curved in two directions and I prefer to make them pre-curved instead of pressing them in the right curve. So, first thing is to make a mold with the right curve in it. I did this by infusing a sandwich panel against the outside of the cabin wall. So far the easiest part. Next is depending on which glazing material will be used .... to be continued.

Click to open photo galeryDeck hatches: Well, it is a one-time opportunity so I choose for the difficult option of flush hatches, which I found in Lewmar as the most economical ones. I like fresh air and lightness and ordered one size 60 in the fore deck, two size 10 in the head and opposite passage way, two size 30 in the cabin roof and one size 54 in the aft cabin. Flush with the deck means also a water drain below the deck and that will be the next challenge to resolve.

Aft cabin and cockpit construction: With respect to the vacuum infusion of the deck there is a natural separation between the deck and roof of cabin and aft cabin, as a result of the aft beam construction. So it is not necessary to infuse the whole deck at once and therefore I have decided to first infuse the roof of the aft cabin so I can finish the construction of the aft cabin and cockpit.

To get some more room in the cockpit I made the seats 175cm long (my body length) instead of the 168cm in the plans. (for nice romantic sleeping under the stars, etc, etc.) After the mounting of the aft cabin hatch it turned out that I've been a little too enthusiastic with the lengthening of the cockpit seats. To make the hatch fit I had to make a cut out in the bridge and that just didn't look very well. The other option, positioning the hatch more aft, is not desirable because of the position of the main sheet track. Repositioning the latter results in less pushing force in the boom to help mast rotation so the mainsheet track dominates the position of the rear of the hatch. To resolve this I've added two extra foam panels to the front panels of the aft cabin which resulted in a correction of 32mm, which is just perfect.

Oh well, it seems you shrink as you get older.

Click for photo galleryRudder construction: During the construction of my boat, I have gotten a lot of relationships with other boat builders, both domestically and abroad. The exchange of experiences has proved extremely valuable and is also one of the many fun incidentals of such a DIY project. Here in the Netherlands are two fellow boat builders who are both involved with CNC technology. Bert (F39) as a professional and Nico (F82SR) as a hobbyist. The fabricated parts and the mold for the daggerboard are being made by Bert​​. And just  recently Nico offered to make the two rudder plug halves for my F39. Nico is an airline pilot and spent his lonely days somewhere far away in a hotel room on the programming of hundreds of lines in the CNC software for my F39 rudder. Great job Nico and thanks again.

So, as an intermediate little project, I am now working on the two by Nico's CNC router milled rudder plugs in order to make a solid reusable rudder mold of it.

Deck laminate and vacuum infusion. Finally it is time to finish the final structural part of the main hull. This is also the last big vacuum infusion. After this the hull is structural sound and finished except for the final post curing. It is a big bag of 12x6m and the infusion strategy is again a simple straight forward setup with just 4 single vacuum ports and a resin feeder line going all around. At this moment the vacuum bag is ready but still not airtight. the leaks are still to big so I cannot hear them and because of my bad hearing I need some help with this (read younger ears ;) My goal is an infusion next weekend.

Click for studypageSteering studypage: Designer Ian Farrier provides various options for the steering possibilities for the F39. Unfortunately none of these meets my needs.

There are two kinds of sailors. Those who like tillers and those who like wheels.  First of all there is the choice for tiller or wheel. Just like everything else to do with boats, the wheel/tiller debate is highly subjective. Both systems have their own pro's and con's. I always had boats with tiller steering. For me this alone is a good reason for a change. One of the advantages of a tiller, the simplicity with only a few moving parts, is not going to work in the F39 centre cockpit. Like the wheel steering a tiller also needs some kind of mechanical transmission to the rudder stock.

Then there is the aspect of space. The tiller devides the cockpit in a starboard and port part. In this rather small cockpit this compromises access to the coveted space under the dodger. The wheel on the other hand devides the cockpit in a fore and an aft part. The helmsman has is own part of the cockpit. I love that more than a sweeping tiller. Standing behind a wheel while maneuvering in close quarters is more comfortable than with the tiller between the knees. So, for me enough reasons to go on with a wheel.

Now what size? A wheel with a size small enough to walk along is not what I want. In that case I would have bought a sports boat ;) So as big as possible which turned out to be 900 mm. at a height of 800 mm.

As now these basic questions have been answered the next step is the most difficult one. The decision about the transmission system. Roughly there are four basic types, in order of my preference :

     1. Rack and Pinion steering - sound and straight forward.
     2. Transmission steering - sound and good rudder feeling;
     3. Cable or rope steering - in my opinion too prone for faults so not for me;
     4. Hydraulick steering - no rudder feel, also not for me;

Transmission steering system: Although I prefer the rack and pinion option this system didn't made it till the implementation stage. The space in the stern is too small and too narrow to make an optimum use of a wide angle geometry. This smart geometry results in a very direct steering amidships (where the loads are low) and a more indirect and powerful steering at full rudder (where the loads are maximal). Also the draglink from pedestal to rudder, with a length of almost 3m. (10ft) , needs a lot of space for its movements (and a big hole in the aft beam bulkhead). Enough reason to forget the rack and pinion system.

Click to enlargeWhile maintaining the wide angle geometry I decided to change over to a transmission steering system made by the Danish Jefa. This system is based on the same principals as the rack and pinion system; the rotation of the wheel is transferred to a push pull movement via a gearbox and levers.

However, also due to the limited space behind the stern, the proposed position of the bevel reduction gearbox is too far aft with the consequence that the position of the torque tube doesn't match with the height of the cabin bed. The torque tube is intended to go underneath the bed bottom.

The solution is to position the whole rudder 96 mm further forwards. This means that the wideness of the lower step in the stern has to change from 374 to 278 mm. Resulting in a 210 mm. extension of the reduction gearbox shaft.

The above drawing is the final design and ordered Jefa parts. The bevel reduction gearbox is housed in its own watertight compartment and separated from "outside" by a watertight roller bearing. The connection of the autopilot drive is at the front of the bevel box right under the steering pedestal. The autopilot drive will be ordered at a later moment. The still missing pedestal is on my design board and will be built in composite by myself.

The webalbum (under construction) is here.

(to be continued)