I prepared the livewell hatch for new coring by first masking over any screw holes on the top, visible side of the panel.  Afterwards, I cut pieces of 1/2″ solid fiberglass sheeting as needed to provide a solid glass edge to the cutout in the hatch, as well as around the latching mechanism.  I didn’t have a lot of 1/2″ material on hand so I repurposed a piece that was just the right size, but had four holes drilled from some past attempt as a backing plate; most of this section would later be drilled out for the 2″ hole required for the latch, and in any event I’d just fill the existing holes with epoxy during installation.

With the borders and solid areas determined, I cut 1/2″ balsa core to fit the remainder.  The open areas near the aft end of the hatch (bottom edge of the last phot0) would eventually be filled with solid fiberglass to create the proper thickness and taper into the cored area as elsewhere on the part.

After final preparations and cleanup, I installed the new core and fiberglass edges in thickened epoxy adhesive, then added weights to hold the core tightly into the adhesive while it cured.

After masking over the screw holes from the top side of the large fuel tank hatch, I cut fiberglass to fit all 10 of the generally-rectangular voids I’d opened on the underside:  five layers of 1708 to fill the voids flush, then a slightly larger layer to overlap the previously-prepared areas of the adjacent panel.

After cleaning and preparing all areas, I started with some thickened epoxy and filled the existing screwholes and any small voids around the edges (particularly the outer edge) where I’d reamed out the old core.  Then I wet out and installed all 60 pieces of cloth to fill and repair all 10 voids.

To provide access beneath the new outboard well, I chose two large round access hatches.  I selected these rather than rectangular versions because they fit the narrow space well, and I thought they’d give better access overall, and because the lids were completely removable for better access; the plastic rectangular hatches have lids that only hinge open, and in this confined space would generally end up being in the way.  Now I marked an actual centerline on the deck panel (while installed in the boat), and after some additional layout positioned the two hatches near each end of the deck and made the round cutouts as needed.    Later, next time I was working with epoxy,  I’d ream out the core from the new openings and replace it with solid epoxy to prevent water ingress, but for now I was pleased with the access these openings would provide to the bilge beneath, for the bilge pump, hoses, or electrical needs going forward.

 

The new sandwich assembly for the outboard well deck was ready for final shaping.  After “unmolding” the part and exposing the flat, if slightly textured from the molding medium (i.e. plastic sheeting), I roughed out the position of the template on the bottom side of the piece, making some reference marks, then used those marks to position the template properly on the top face of the part so I could cut out the shape as required.  I fine-tuned the piece as needed till it fit appropriately in the opening on the boat, resting on the temporary wooden cleats.  The large gaps at the corners of the bowed forward sections would be filled and tabbed over later as part of the final installation; I didn’t extend the flat panel into these areas as doing so would have prohibited installation of the panel in the space.

Later, I lightly sanded both sides of the new panel, focusing on the top surface to remove the smooth, shiny texture and prepare it for additional work before and during installation.  The level, placed flat on the underpinnings of the main deck forward of the cutout, shows roughly the angled pitch of the new panel towards the transom, with approximately 3/4″ – 1″ of pitch over the three-foot length of the panel.  Final installation of the panel would happen soon, but not before I wrapped up some work in and around the area soon to be covered over.

Meanwhile, I picked up again on the fuel tank hatch, turning to the second side, where I opened up the bottom skin as needed around the fastener locations to expose and remove wet or damaged core back to sound material at each spot.

Afterwards, I ground small tapered areas around each repair, cleaned up the exposed laminate, and lightly sanded the gelcoated underside of the hatch to prepare for rebuilding and refinishing.

I cut open the underside of the livewell hatch, choosing an initial cut area that I thought seemed large enough to encompass all the damage.  Later, I slightly expanded the cut on the ends to access all of the wet and blackened core at the perimeter.  After removing all the core in the exposed area, I prepared the surface for new core and fiberglass in the usual way, including boring out the underside of the hinge screw holes to eliminate future core worries there once the hatch was reinstalled.

While I had the sanding tools going, I prepared  for patching the now-obsolete engine vent openings on each side of the hull near the transom, and prepared as needed the forward end of the engine room opening for  the eventual installation of the new splashwell bulkhead and deck, removing the temporary wooden cleats after marking their top edges for reference.  I also scraped out the remaining sound insulation and adhesive from the fiberglass engine room cover/splashwell, and sanded the inside and other surfaces to prepare for installation.

After cleaning up, I made new fiberglass cleats from prefabricated fiberglass panels and installed them with epoxy adhesive in the engine room along the sides, transom, and at the forward end, replacing the wooden versions I’d used for the mockup and templating.

 

To begin, I laminated the three layers of fiberglass I’d previously cut with epoxy resin, creating a top-skin panel for the new outboard well deck.  While the initial layers were gelling, I prepared a section of 1/2″ balsa core to fit, using the overall template as a guide, then cutting the core 3″ short on all sides to leave room for a solid flange where the deck would rest on various cleats and supports along the edges during installation.  I cut a bevel on the outer sides of the core to allow fiberglass to lay over it during installation.

Once the three top layers had sufficiently cured, I made a light outline of the template on the surface and positioned the new core within; the rectangular base panel was sufficiently oversize that I had ample room on all edges for adjustment.  I pre-wet both sides of the core with resin, then installed it in a bed of epoxy adhesive before installing two additional layers of 1708 over the top of the core to complete the laminate structure for the sandwich.

The owner reported that the hinged hatch for the livewell, and the semi-permanent hatch over the fuel tank, showed signs of core damage or water intrusion.  The livewell hatch was obvious at casual observation, as the aft edge, where it had been cut to accommodate the original jet drive installation, had obviously been poorly sealed–or perhaps not sealed at all–and the core there, such as remained, was exposed to the elements and in poor condition.  The condition of the larger hatch over the fuel tank was less obvious immediately, but now I removed both pieces so I could address the necessary repairs.  Removal was quick and straightforward.

It was clear the livewell hatch would require new core and bottom skin, retaining the original top with its molded pattern for cosmetic reasons.  I removed the latching mechanism, devoid of sealant, to expose more of the core, and set this piece aside to deal with later.

At initial inspection the fuel tank hatch seemed generally in good condition, but some careful exploratory inspection revealed evidence of water intrusion through the screw holes along the edges–both the fixing holes, as well as screw holes from the deck seating (previously removed).  But my sense was the overall structure was sound, so after setting up some benches I began by opening the bottom skin around a randomly-chosen screw hole, using an oscillating cutting tool.  I found an isolated pocket of damaged balsa core around the fastener hole, but it quickly became dry and sound, so it seemed wholesale core rebuilding would be unnecessary.  Continuing in this way, I opened all the screw locations on one side of the hatch, finding varying levels of core damage immediately at the holes and expanding the openings as needed in each case to expose only clean, dry, well-bonded core at the edges.

This brought me to the end of the day.  Next time, I’d continue on the other side of the hatch, then begin repairs, for which I planned to install solid fiberglass at each of the openings, filling them to the level of the existing skin.  This would not only replace the damaged core, but also prevent further water issues once the piece was reinstalled.

The next stage of the modifications to the transom involved the open deck area, leftover from the original jet drive engine installation.  To finish off the structural repairs, I needed to build a new deck to enclose the bilge, and create the usual splash well forward of the outboard cutout.

The owner and I previously discussed modifying the original engine box cover to work as the forward end of the splash well, mainly because it was already a reasonable fit, and handled the various different shapes of the cutout with minimal need for additional modification.  To begin, I removed the sound insulation from the inside of the cover, to lighten the piece and prepare it for cutting.  The insulation was glued in place with an adhesive flexible sealant and came off relatively easily, though there’d be substantial surface prep required on the inside surfaces later.

I set the hatch in its proper position in the boat.  The angled portion of the forward side seemed the appropriate place to use as a finished height for the modified piece for several reasons, from cosmetic to the fact that, at about 12-1/2″ up from the deck, it just happened to be a good height to begin with.  Using various tools I struck this line around the sides of the hatch , eventually intersecting with the molded seats/storage areas on either side.  My first line turned out to be in the wrong place, so I struck it out.

Happy with the initial line, I brought the cover to the bench and used tape to mask off the line for greater visibility.  Then, I struck a new line 1/4″ above, using a scrap of plywood as a guide, and masked to the new line; this would be the cut line, a bit above the hoped-for line, to allow me room for adjustments later after the test fit and proof of concept.  Happy with the line from a visual perspective, I made the initial cut with a jigsaw, removing the top of the old engine box.

I test-fit the modified bulkhead in the boat and made a couple measurements of the inside width and distance from the transom to confirm the owner’s choice of outboard would fit when tilted up.  My eventual plan was to secure this piece in place with epoxy and fiberglass from the inside, incorporating it with the new splashwell deck.  For now, the test-fit was complete and I set the assembly aside.

The splashwell deck had one known reference point along the forward edge of the engine room cutout, which was the aft edge of the main deck in way of the livewell locker opening.  From here, the deck should pitch aft to drain water naturally out the transom, where eventually I’d install a pair of small scuppers, one per side.    To determine the aft end position, I used a stiff straightedge held tightly against the plane of the main deck forward of the cutout, and extended it aft to the transom to make a couple reference marks.  From the initial marks, I adjusted them downwards to allow for the depth of the forward edge below the main deck, plus an additional distance for drainage, or roughly an inch total.

After I’d made these initial marks and begun some additional layout, I realized they weren’t correct, and made some new reference marks, beneath which I temporarily hot-glued a scrapwood cleat at the aft end.  At the forward end, I hot-glued another small cleat beneath the exposed deck edge.  These formed the two key points to determine the new deck’s plane fore and aft; it should be pitched roughly 3/4″ down towards the transom.

Now I needed to transfer that plane to the sides of the compartment so I could install additional temporary cleats.  I installed three longitudinal strips of plywood, on edge for stiffness, to span the space between the forward and after cleats, then used another piece of the plywood held tightly against the bottoms of those cleats to make several reference marks on each side of the compartment, to which I could hot glue additional cleats.

With the new deck plane defined on all four sides, I created a template of thin strips of plywood hot-glued together in the required shape of the perimeter.  I’d use this template to cut the custom fiberglass deck to shape once I built it.  With the template complete, I checked the position at the aft end with my straightedge once more, with the straightedge held tightly to the plane of the main deck.  The aft end was appropriately lower than the forward end when I measured both.

I struck a mark to show the waterline (or at least the top of the antifouling, good enough for this) on the exterior of the transom so I could check that the new deck inside would still be above the waterline for the small drains; they would be roughly 1″ above the waterline as defined by the top of the antifouling (itself a bit above the waterline).

To use up what remained of the day, I cut several pieces of 1708 biax somewhat larger than the template, and prepared a flat molding table to build the new deck.  I’d continue this process next time.

Another round of sanding brought the large bottom patch tantalizingly close to its final shape, with only a few small voids requiring more attention, as well as some additional work needed at the transition to the transom.

The transom portion of the patch grew closer as well, though some fine-tuning remained, particularly at the lower edge,  The adjacent work on the transom, including smaller patches and hole-filling, would continue to be refined as I moved ahead with additional rounds of fairing compound on the transom cutout and environs.

I spent the first part of the day sanding the fairing on the bottom and transom, and the new fiberglass on the transom cutout.

On the transom, once I’d sanded the various holes I’d epoxy-filled earlier, I prepared small fiberglass pieces to fit each spot and installed them in epoxy resin, leaving this to cure for a bit before proceeding with fairing compound over the various areas on the transom, including the patch over the jet tunnel and the beginnings of the fairing for the new tabbing all around the transom cutout and related areas inside the boat.

The work on the bottom was close to where it needed to be, but there were low spots running fore and aft on both sides, between the centerline and the outer edges of the repair, so when I applied the next round of fairing compound, I focused on these areas to bring them into spec.  The forward portion of the repair needed only minor touchups at this point.

 

Sticking with the usual cycle, I began the day with more sanding, focusing on the bottom to clean up the new fiberglass there, then continuing with the transom fairing as needed, and the outboard cutout where I’d slightly filled the edge of the new top laminate.  I also used a grinder to open up several larger, abandoned holes in the transom (leftover from various through hulls and wiring clamps), and reamed out the small screw holes leftover from the wooden transom veneer, all to make these ready for the first stages of repair and filling.

After cleanup, I applied a round of fairing filler to the bottom.  The basic profile and shape was close to final, so the fairing was mainly to fill the weave of the cloth and burnish the edges of the laminate.

Continuing on the transom, I applied a second round of filler on the vertical part of the jet tunnel, then into the various screw and fixture holes about the rest of the transom.

Later, I patterned and cut layers of fiberglass to fit over and around the transom cutout, then installed the cut pieces in epoxy resin.

Continuing the work on the combined transom and bottom repair, I started the day with a round of sanding to prepare the fresh fiberglass on the transom portion of the jet tunnel for the next stages of work, as well as to sand and lightly shape the forward part of the bottom vee, forward of the jet tunnel where the boat had originally had the flat area to transition to the tunnel.

I sanded smooth and flush the extra layers of fiberglass I’d added to the new transom cutout to raise its height a bit, bringing it now to about 23-3/4″ from the center of the bottom vee; the final height was to be 24″, and the extra 1/4″ would be made up by the final tabbing to wrap over the cutout and tie it in with the surrounding surfaces.  Meanwhile, I also sanded smooth the first round of fairing filler I’d applied to portions of the transom on each side; there’d be more to come.

After cleaning up, I prepared a pattern of the remaining fiberglass patch required on the bottom, which would extend from the transom (where I’d set up the fiberglass with a series of 3″ steps between layers to allow for overlap) forward to a point just ahead of the area formerly known as the flat, and which new layers would extend out onto the hull several inches on each side to complete the tying in of the repair work with the existing hull.

Because I’d never be able to handle such large pieces overhead, I divided the fiberglass into two manageable sections:  The first extended from the new transom glasswork to a point 9″ forward of the old tunnel location; the second section finished off the laminate from there.  In each case, subsequent layers were staggered and overlapped by 3″.

After final preparations, I installed the six new pieces on the bottom, completing the major fiberglass laminates of this repair.

To complete the day, I applied a first round of epoxy fairing filler over the vertical part of the transom repair, filling the cloth weave and low areas, and filled a small void beneath the new fiberglass on the transom cutout, bringing it flush since the cut had been rounded over before I applied the new layers.

After a light sanding and other preparation at  the forward vee portion of the repair, I applied a second round of fairing filler to take care of t he low spots left by the first-round troweling.  These efforts were designed to recreate the basic shape of the previously-flat spot on the hull, and with the second round it appeared close to the final shape needed before I could fiberglass over the whole area.

I had some fairing compound leftover, so I applied it to portions of the transom that were damaged during the wood veneer removal.

At the transom, I’d hoped to laminate three layers of cloth over the entire vertical transom repair, and overlapped 9″ onto the bottom, which would allow me to offset the three layers by 3″ each to provide overlapping room for the fiberglass to continue forward over the remainder of the bottom repair.  However, I simply couldn’t make the cloth take the required shape, what with the V-shape, not without huge and unwanted darts and cutouts in the cloth, so I changed my plan to one that would work.  I kept the 9″ overlap on the bottom (with the subsequent two layers spaced 3″ back in each case), but reduced how far up the vertical transom they came, with the largest layer extending 3″ up, and the remaining two staggered 1″ down.  I could make the cloth conform to this shape.

Above this, I installed three layers over the vertical part of the repair, butting the first layer against the upturned bottom layers, then overlapping the subsequent two layers appropriately over their staggered counterparts below.  I finished off the transom fiberglass for now with two smaller layers that filled the slight depression over the vertical part of the old jet tunnel, bringing this area nearly flush with the surrounds.  I let these layers hang just below the bottom for later trimming.

To round out work for the day, I installed six layers of 1708 over the top edge of the transom cutout, which would increase the height a bit to bring it closer to the required 24″ from the bottom of the vee when all was said and done.  Later I’d wrap more fiberglass over the entire cutout, which would bring the height up to the final dimension as well as tie it in the new cutout and complete the work there.  I let the strips of fiberglass overhang the opening a bit for later trimming, and used some thickened epoxy at the ends to reform the curved shape at each lower corner.

 

Before heading off to a morning appointment, I sanded all the new work from last time, starting with the forward vee.

At the transom, I sanded as needed to bring the new layers of overhanging fiberglass flush, and to prepare the new core and environs for future steps.

Inside the boat, I lightly sanded the new glasswork on the inside of the transom.

Later, upon my return, I applied a coat of fairing filler to the forward vee, using an improvised 24″ long batten to span between the ‘known” hull shape at the forward and after ends of the space previously known as the flat.  The many layers of fiberglass I’d applied had mostly filled the space, but now I could use fairing compound to finalize the shape before laminating over top.  This early round of filler was slightly rough because of the imperfect batten, but did its job of defining the shape well enough that the next round of filler would come close to establishing the shape required before fiberglassing.

Preparing for eventual fiberglassing at the transom and over the bottom of the tunnel patch, I started with a pattern of the vertical transom and onto the bottom going forward 9″.  I’d eventually stagger three layers of fiberglass over this area, conjoined with three adjoining and subsequently overlapping layers over the remaining part of the bottom patch.