SEDATION 4  Closing-Up

With the majority of pre-molded components and panels now in-place, it's time to close-up the remainder of the exterior.  All these little details are difficult to categorize for the web site so this page serves as a catch-all for the respective odds-and-ends.  In this photo, positioning of the 3 cabin roofs is complete and the yellow bow section of the bridgedeck has just been installed
Over 101 ft² (9.38 m²) of surface area is exposed to the ocean on the slanted bow section alone.  Slamming into a large wave, during a storm for example, exerts tremendous forces which must be transmitted to the adjacent structure. A complex lamination schedule was developed to optimize strength accordingly.  At the exterior hull joints, alternate layers of bi-axial fiberglass fabric are applied with ±45° and 0°-90° fiber orientations.  Along the bottom edge, there are 3 such layers of external laminations.  Interior joint laminations are similarly optimized.
Attachment of  the pilothouse- and saloon-roof to the side walls utilizes two layers of ±45° orientation bi-axial at the interior joints and a single large-area lamination externally.  We kept the huge pilothouse windows in-place, protected by clear plastic sheets, during this process to assure precise fit during subsequent final installation.
The center section of the windshield is another highly stressed component since it connects the pilothouse roof with the 5° slanted roof, above the staterooms, and the mast tube.  There are several complex intersections of various geometry here and laminations are tricky.  I hand-fitted the 1.5" thick panel to achieve < .060" gaps at every joint.  At the lower interior junction a small triangular double-lamination reinforces the deep recess formed by the mast tube and center panel on each side.  In this photo, a test piece of bi-axial fabric is fitted to study fiber  alignment and optimize bending without excessive crimping, but no combination of shape and orientation looked promising.  Using expensive 2408 material for these joints is a better solution as it is more pliable.
The molded one-piece forward deck (foredeck) was removed from the mold and trimmed before initial fitting.  From the top this panel appears deceivingly simple but the extensive combination of molded-in features underneath must be seen to be appreciated.
I snapped this picture just as gel coat application was almost finished.  Notice the two square sections marked on the mold; the forward area is where a bollard will be thru-bolted and the outboard area, further aft, will support one of the anchor windlasses.  A 1/4" joggle is molded-in along the forward edge to facilitate smooth transition between the 3-layer external lamination which will wrap around the hull-to-deck joint.
To assure optimum strength, there is no honeycomb core at the multiple component-mounting locations.  Numerous layers of bi-axial fiberglass are laminated in these areas instead.  After the honeycomb core is installed, more layers tie-in the laminate layers on each side of the core.  Solid thickness along the forward edge exceeds 1/4".  The bollard- and winch-mounting areas are nearly 1/2" thick solid fiberglass!
Slanting the deck slightly forward is desirable to enhance drainage.  Adding a slight "crown", by raising the center, also promotes drainage.  During the initial test-fit, we started with a 2" rise at the centerline.  This appears to be the limit of bending obtainable from the extremely stiff molded foredeck.  Look closely at the distorted reflections to see the crown.
Fabricating the steps, between the side decks and foredeck, was an artistic exercise.  Since the outboard surfaces of the side decks slant at 4° and the foredeck is essentially flat, I decided to slant the steps 2° outward for esthetic purposes and to promote drainage.
Using the ShopBot, I cut mock-up patterns of the windshield panels, from R-max foam insulation material, to verify proper fit.  The windshield slants at 30° thus the top- and bottom-edges must be hand-sanded since the ShopBot (not a 5-axis CNC machine) will not cut these features.  I've decided to install each windshield during the hand-fitting process to assure flatness, hence 100% watertight sealing when closed.
A mock-up of the Aft Pilothouse Window panel was, similarly, cut from R-max.  These are simple flat panels, which intersect two molded roofs,  so the fit is perfect.  These windows are fixed 3/8" tempered glass (non-opening) and enhance rigidity of the roof assembly while providing illumination with enhanced visibility.
All laminations within the stateroom areas are completed.  Here's a shot of the guest quarters ready for interior decoration.  Notice the sunlight illuminating areas where gel coat was sanded for laminations.  This phenomena may be exploited by masking-off certain areas, when we paint the interior, to provide subdued spot illumination.
We placed the three 57 gallon water tanks to fit appropriate rubber-padded mounts.  Valves, filters and the freshwater pressure-pump will be in this area, forward of the guest bed.  I realized that an access crawl space could be obtained by splitting the 3 stringers which connect the foredeck to the slanted bow beneath.  The I-beam seen at right is placed above the aft face of a full-width mini-bulkhead.  It may be tight for me but a smaller person should have no problem reaching any portion of the water tank area.
A small access door was installed in the forward stateroom wall accordingly.   In this picture, shot through the access door, the port-forward stringer is being placed.  My "crawl space" is fairly roomy after all.  Reaching any mounting hardware for rails stanchions, bollards etc. will be easy.
Plumbing installation was tedious due to the slanted bridgedeck floor.  All 3 tanks share a common vent line which spans the wall immediately above them.  This line may also be used by watermaker to replenish the on-board supply.  As with the fuel tanks, all are padded with 3/8" neoprene rubber.  The 3 water-fill deck plates are the ONLY foredeck holes into this area.  Clean rags are stuffed into the fill fittings until the foredeck is installed.  The markings on the wall indicate the precise locations for drilling of the deck plate holes afterward.
There are NO hatches on the foredeck, hence zero potential for leaks.  This dry "water room" will ventilate through both stateroom forward closets (cedar lined) so musty smells or insects will not be an issue.  Here's one final look before the foredeck is installed.
I cut the final Pilothouse Aft Window panels, on the ShopBot, then we installed and clamped the windows to assure flatness before positioning.  The 3/8" solid tempered glass windows are heavy but installation took only 3 minutes each.  The quality and fit of these custom American Marine Products windows is astounding.
Installation of the foredeck proceeded without incident.  Paco volunteered to detail the water room's interior immediately afterward.  In this shot he is working behind-his-back on the starboard tank bulkhead while I'm just inside ahead of the access door.  Forced ventilation was provided by an axial fan at the starboard access hatch to avoid overexposure to vinylester resin fumes.   Lighting is good, albeit eerie, with shadowless yellow illumination from below.
With the foredeck now in-place, the surface's geometry may be appreciated.  From the flat/straight bow the deck rises 2" at the centerline of the staterooms' bulkhead and curves slightly to a 1" rise at the outward edges.  This assures drainage and looks pretty too.
Before we touch-up the yellow gel coat beneath the bridgedeck, a few details required attention.  The freshly laminated area in this picture's background is a fuel line conduit at the forward edge of the transition between the bridgedeck levels.  Paco molded a nice 90° 2-ply radius shape using Ø4" PVC for a mold.  We applied one layer of fiberglass directly on the step's seam then positioned the molded 90° radius piece before 2 more layers were laminated atop.  This results in a graceful transition between the bridgedeck levels with an integral "bullet proof" conduit for the fuel lines between the hulls.  The 3 white pipes in the foreground are electrical conduits.
Connecting electrical circuits between two widely-spaced hulls is a challenge which few catamaran designs solve gracefully.  I decided to use three parallel lengths of Ø1.25"  PVC thin wall (Schedule 160) tubing for this solution.  They were first glued side-by-side then inserted in slots cut into each hull beneath the bridgedeck.  After fairing, two layers of fiberglass will be laminated around them, creating an additional "hat section"  reinforcement for the saloon floor while protecting the wiring within.  ABYC specifications prohibit adjacent runs of AC and DC wires within the same bundle, so one conduit is for 120V AC use, the second is for 12V DC use and the third is for engine-control and -instrumentation wiring.
The pilothouse windshield panels were cut easily using the ShopBot.  All beveled edges require hand-trimming but the task is relatively quick.  The windshields will be clamped-in before final trimming to assure flatness.  After a few more laminations, the pilothouse will be completed.
With all bulkhead and deck connections completed, the vessel is fully self-supporting.  All temporary braces were removed and no settling occurred.  SEDATION 4 is stiff!  In this shot, looking along the underbelly, the high bridgedeck-to-water clearance is evident.
Less than 70 hours until launching and all is well.  We only have a few hundred more critical details remaining :)  The rapid pace of progress toward a project's deadline is always astounding to experience and our adrenaline levels are running high.  Drying time for paints is going to be an obstacle so around-the-clock shifts will probably ensue these last few days.