Cockpit Access Hatches
This page was last updated on 10 January 2004.

Cockpit Sole Access Hatch
oldhatch.jpg (14330 bytes)
When I redid the cockpit a few years ago during the complete boat restoration, one of the most important improvements I made was to install a large access hatch in the sole above the stuffing box and aft end of the engine.  At the time, I hemmed and hawed about what sort of hatch to install--I was sorely tempted by some nice-looking aluminum flush hatches, but in the end I chose a plastic hatch made by Tempress.

Revisit the original hatch installation by clicking here.

The Tempress hatch performed adequately for three seasons, and the large size was a boon to the bilge access beneath the cockpit.  But the hatch leaked when there was water in the cockpit, which was at a minimum an irritation--and could lead to unwanted flooding of the bilge.

I had removed the plastic hatch to make it easier to repaint the nonskid earlier in the month, so the time seemed ripe for a change, if indeed I was ever going to do it.  I already knew about one aluminum hatch, made by Bomar, that was nearly the same exact size as my current one, but it was expensive, so I perused the catalogs to check out other options in watertight deck hatches.  I considered a line of flush aluminum hatches from Anchor Marine, available at Hamilton Marine, but discovered that there was not a size that matched closely enough--meaning that I would need to make serious modifications.

Finally, after confirming measurements once again, one day I just ordered the darn hatch that I wanted.  I couldn't--and still can't--point to the exact moment and reason behind my impulsive decision, but I guess I decided to just stop messing around and get what I knew was inevitable anyway.  I had wanted this hatch three years ago...now just seemed like the perfect time, I guess.

alumhatch1.jpg (39889 bytes)The hatch I ordered is a Bomar cast aluminum inspection hatch, part # BOM-C4T1020, available at Hamilton Marine (order #147407; $357.99). The hatch required a 21" x 12" opening, which tied in nicely with the 21" x 11" cutout that was already in the sole from the old hatch.  All I'd have to do would be to widen the cutout by about an inch--no trouble at all.
alumhatch2.jpg (40463 bytes)The hatch arrived quickly, even though I had received an email from Hamilton saying it was backordered.  What a nice piece of hardware...machined aluminum, with two large locking dogs on one side of the hatch, and two stainless steel pins on the other side to lock it in place.  I felt better already.
alumhatch3.jpg (34690 bytes)

openingmarked.jpg (23402 bytes)I marked the shape of the new hatch on the cockpit sole, and made preparations to enlarge the opening as needed.   Unfortunately, I managed to severely drop my jigsaw 10 feet to the concrete floor, ruining the table and chuck in the process.  So I had to put the hatch installation on hold for a few days till I could get a new saw.  Rats.

hatchepoxyfill.jpg (41060 bytes)Armed with a  brand new saw several days later, I enlarged the opening as necessary.  I made some fine adjustments with a grinder till the hatch flange fit into place.  Then, to prepare the opening, I removed 1/2" or so of the balsa core material from the exposed back edge and filled the resulting gap with thickened epoxy, to seal the opening and prevent any possibility of moisture intrusion through the cutout. The other three edges were in nearly the same positions as they had been with the old hatch, and had been previously filled with epoxy when I installed the original hatch.

solehatchdrilled1.jpg (42672 bytes)After the epoxy cured overnight, I continued by placing the hatch in the opening, ensuring that it was centered and otherwise properly positioned, and then drilled small pilot holes at each screw location with a Vix bit (a self-centering, spring-loaded bit designed for this purpose).  With the flange screw locations thusly marked, I removed the hatch again and, using a 1/2" Forstner bit, enlarged the holes at each location, drilling through the top skin and core, but not through the bottom skin.  In this manner, I removed all core material from around the eventual screw locations, eliminating the chance that minor leakage could saturate the core.  I replaced the flange one more time and taped the deck off around it for protection.

solehatchfilled.jpg (45436 bytes)Then, I mixed a batch of loosely thickened epoxy and poured some into each of the 1/2" holes I had drilled, filling them with solid, strengthened epoxy.  The screws will penetrate through this epoxy, which is not only strong, but also isolates the screws from the core, preventing any moisture intrusion issues.  Since any forces on this hatch will be from above--whether water, persons, or gear--I saw no reason why screws would be insufficient to hold it in place.  I left the epoxy to cure overnight, as usual, before continuing with the installation.

newcockpit-hatch.jpg (30375 bytes)Once the epoxy had cured, I set the hatch in place temporarily and redrilled the pilot holes for the installation screws, once again using the Vix bit.  Then, I installed the hatch in a heavy bed of 3M 101 polysulfide.  The underside of the hatch flange features two grooves to ensure sound bedding in all areas.  I secured the hatch with #10 x 1-1/4" screws.  I cleaned up the excess caulk, removed the tape, and the job was complete.
newhatchopen.jpg (25361 bytes)
Cockpit Seat Hatch:  Battery Access
When rebuilding and reconfiguring the boat,  I elected to install my batteries in the cockpit lockers, at the forward end of each side--a single engine starting battery to port, and two ship's batteries to starboard.  The location was great in many ways:  out of the way, yet close to the engine and electrical panel, and in space that would otherwise be wasted or at least underutilized.

Click here to revisit the original battery installation.

The same qualities that made the space desirable, however, made it a bear to get the batteries in and out of the boat--especially the big T-105s on the starboard side.  And the location meant that it was impossible to check the connections and electrolyte level without moving the batteries aft into the open--which was difficult enough, given that the batteries were stored in deep trays to prevent movement, and the cockpit locker lid molded scupper arrangement severely limited space to muscle the big batteries around.  Add to this the fact that the T-105 golf car batteries have no straps, and one has a recipe for frustration in the making.

With our short sailing season, I found that it was unnecessary to check the levels during the season, only doing so in the fall when I removed the batteries for winter storage.  But I felt this was less than ideal, long-term.  Finally, when removing the batteries from their trays to open access up for replacing the scuppers, the last straw broke.  Fighting the batteries out one last time, I vowed to never replicate the unpleasantness again.

portbattery.jpg (60604 bytes)     stbbattery.jpg (59696 bytes)
Port and starboard battery locations, respectively (looking forward)

The port side was less of a problem, with its smaller, lighter, single battery, which fits nicely in a pre-bought plastic battery box.  This one is not a big deal to slide aft for inspection or removal, so I decided (for now, at least) against changing the access on that side.  For the starboard side, though, I decided upon a 10" round aluminum hatch by Bomar, one of similar looks and construction to the larger cockpit hatch.  Having upgraded the cockpit sole hatch to a solid, seaworthy one, I had no interest in installing some flimsy plastic wannabe hatch over the battery compartment, so I was left with no choice but to spring for the pricey aluminum version.  Anyway, I had been eyeing them for years.  Although a day or so earlier I had decided that, despite the chore of removing and installing the batteries, I probably could get away without installing the hatch, one afternoon I just decided to run out, buy the hatch, and install it.  Such are the inner workings of my mind.

roundhatchhole.jpg (36237 bytes)With the new hatch on hand, I chose the location for its cutout on the starboard cockpit seat, just forward of the locker hatch.  After double checking the location to ensure that there were no obstructions, I cut the circle out with my jigsaw.  Immediately, I realized with great pleasure what a difference the hatch would make to my life, and to accessing the area beneath, and I was thrilled.  The cost was soon forgotten, as it usually is when a worthy purchase is made.  Fortuitously, my spacing for the hatch ended up symmetrically aligned with the three factory-glassed plywood supports beneath the cockpit seat, which meant that the screws securing the hatch would have plenty of solid material in which to bite.  Sometimes one gets lucky.

roundhatchgooped.jpg (45160 bytes)I installed the hatch in a thick bed of polysulfide caulk, after outlining the perimeter with masking tape in the usual way, and secured it with 1" stainless steel screws.  The new hatch was not large enough to allow the batteries to be lowered straight into the locker--one option I had considered--but allows excellent access directly above the battery location, so that horsing the batteries into place will be possible from both sides.  And with the new hatch open, direct top access to the terminals and vent caps was possible, solving the maintenance and inspection issue once and for all.  As a bonus, the new hatch allowed outstanding access to the inside of the engine control, and to the deck drain hoses.  During the season, we always keep the cockpit cushions in place on deck, so the new hatch will be covered and out of sight--though the machined aluminum has a sort of institutional beauty of its own.

newroundhatch.jpg (24482 bytes)     insideroundhatch.jpg (45638 bytes)
The new hatch in place, left, and looking inside (batteries not installed)


Glissando, Pearson  Triton #381

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