Installing the Bilge Pump Through Hull

With the pump bolted into place and the hose securely attached to the barb fittings, the last thing left to do was install the actual through hull fitting in the side of the boat. This may sound like a simple task, but it involves drilling a massive 2.5 inch hole in the side of the boat to accomplish the installation.

Whenever I need to drill a hole in my hull, I always measure everything multiple times to make sure that I will put the hole where I think it will and not somewhere I don't want the hole to be. After I am certain that the hole will end up where I want it, I drill a very small pilot hole. The idea behind the pilot hole is it lets me verify that the hole will come out where I think it will. If I had made a mistake, this small hole is easy to fix and the correct hole could be drilled later.

Most importantly, if you miscalculate your hole position, you run the risk of drilling a hole below the waterline. A small hole will give you much more time to rectify the situation as compared to a massive hole saw hole! If you mess up with a 1/4 inch hole, you now have an inconvenience that needs to be fixed promptly. If you mess up with a 2 inch hole saw, you now have a serious problem that could sink your yacht promptly.

My plan is to have the through hull be located high above the waterline so that we can easily pump while heeled over, yet be below the rub rail so that the wood doesn't get stained by all the dirty bilge water that will be drawn up and out by the pump.

With the pilot hole confirmed, I set about drilling the full sized hole with the 2.5 inch hole saw. The hull was rather thick and the drill took a while to cut through all the solid fiberglass, but with enough perseverance, light started to shine through the outer ring of the hole and I new I was almost there! When the hole saw punched through the hull, a world of bright light began pouring into the interior of Wisdom, but thankfully no water! Sailboats are deceptively deep in the water, this hole is only a bit less than 2 feet above the water line yet is chest high inside the cabin. 

Bedding compound was liberally applied to the flange of the through hull fitting and a bit of extra bedding compound was applied to the threads near the mushroom. This will seep through everything and seal up all the nooks and gaps that might exist to let water pass through and into the hull while we are under sail and heeled over. 

I pushed the through hull onto the side of the hull from the outside while Maddie threaded the lock ring onto the through hull from the inside. After the lock ring was snugged down, the sea cock was threaded on and tightened. I like attaching the sea cock while the bedding compound is still wet because I can always spin the entire assembly to get the handle lined up where I want it to be.

Since we are above the waterline, a plastic seacock that merely threads onto the mushroom is sufficient. If we were doing this below the waterline, it would be mandatory to use a triangular bolted seacock set up on a raised platform for added stability and durability. This lever will rarely be used, since the bilge pump acts as a check valve preventing water from pouring into the bilge while we heel over and submerge the through hull. If the sea cock were to get stuck from lack of use, I would prefer it to be stuck open where we could still operate the pump. 

If the sea cock is too bulky inside the foulies locker, it can always be removed and replaced with a simple barb fitting to connect the hose. This will be something that we will deal with in the future depending on how it behaves in the locker while we cruise.

The excess bedding compound was wiped off the through hull. There was an even bead that oozed out of the entire circumference, letting me know that the material was properly distributed and dispersed when tightened. 

You can also see the filthy topsides and peeling paint, along with the neglected teak. Part of the preparation to go cruising will involve repainting the entire boat (bottom and topsides) along with bringing the brightwork back to life with a healthy application of varnish. 

Finishing Up the Bilge Pump

The bilge pump supports are ready for the pump. The resin has cured, the paint has dried, and the bolt holes have been refreshed. It is time to connect the hose and bolt the unit in place!

The bilge pump lives tucked away inside the locker when not in use and the handle lives inside the foulies locker when times are dry. When we need to use the pump, the lockers lid can be removed and the foulies locker can be opened up. This gives us plenty of space to stand over the pump and operate the handle.

The handle is kept close at hand in the hanging locker by tying a hitch to the handle and looping the tail over the sail tie hook in the locker.

I was about to make a bracket using a pipe at the bottom and a clip at the top to hold the lever arm in place when not in use. This project would have taken a considerable amount of time and effort when Maddie suggested I tie a fancy knot to the pole and hang it from the hooks that are already in there. 

A simple hitch is all it took with the tails tied into a loop using a sheet bend. There was a scrap piece of dyneema was hanging on a port light awaiting some form of use. In a few seconds, this little piece of dyneema was transformed into the bilge pump handle loop!

The last step in the process will be to bore a massive hole in the side of the hull and install the through hull fitting for the bilge pump discharge. Then this bilge pump will be completely installed and ready for use!

Fiberglassing the Bilge Pump Supports

The bilge pump supports are positioned with lots of chop strand mat wedged between the endgrain and the stripped bulkhead. All we have to do now is glass everything together!

Being how this project site is also my home, I need to make sure that no mess occurs and all the work is contained. By working with smaller sizes, I am able to keep any issues to a minimum and produce a good final product with minimal disturbance to the rest of the boat!

The pure epoxy can be brushed onto the wooden supports with a paint brush just like if it were varnish. It is best to use a disposable chip brush with bristles as a foam brush could dissolve in the epoxy, destroying your ability to apply it and your batch of epoxy resin.

Be sure to saturate the chop strand mat at the ends. The idea of the chop strand mat is to hold wet resin in position as it cures. If you fail to wet the chop strand mat, there will be no bond to the bulkhead! Everything is covered in an even coat of epoxy, the frame, the ends, and the bulkhead as well. I used fast set epoxy simply because it is winter and the low temperatures will greatly delay curing. If it were warmer, I would be using slow or ultra slow hardener, as it would grant me more working time. 

Bilge Pump Supports: Finishing Touches

The bilge pump supports are glassed in and the resin has fully cured, it is now time to clean up the locker and make it look presentable!

It is amazing what a bit of paint can do! I used Interlux Bilgekote after lightly sanding the layer of blushing off the surface of the glassed in supports. Bilgekote is very forgiving and results in a slick finish with minimal preparation work. There is no need to prime the surfaces with primer, all you need to do is lightly sand the surface and then start painting.

The massive bilge pump hose is 2 inches (inside diameter) which will flow many gallons with while keeping back pressure to a minimum. The only problem with running a hose this size is the hole it needs to pass through a bulkhead. The hose narrowly fits through a 2.5 inch hole, and fitting a 2.5 inch hole saw in some of the areas was tricky. In the end, the bilge hose was run with as few turns as possible to minimize resistance in the passage of water.

The bilge hose was run through the bulkheads and down into the bilge with the excess spilling into the locker while I painted. Once the paint cures, I will trim the hose to size and attach the bilge pump to the supports. At that point, all will be finished with the project; save drilling a giant hole in the side of the hull for the discharge through hull fitting. 

Finishing the Bilge Pump Supports

The inboard support was scraped, chop strand mat was squished between the frame and the bulkhead, and the support was screwed into place. Now it is time to do the outboard support.

The outboard support is has a vertical batten running right next to the frame. Scraping the paint off the inside proved challenging! I have been using a regular block plane for the paint scraping, but the blade doesn't reach the edge. I have a rabbet plane, but I elected not to use it because the paint makes a mess of the plane. My block plane is covered with a white mess of dust from the paint and wood after just a few scrapes. The rabbet plane has a lot more nooks for that dust to get into and cleaning it all out would be a nightmare!

Instead, I chose to go a simpler way and use a regular 1/2" chisel. With a sharp edge, the chisel was able to get under the paint and lift it off the wood without taking too much wood with it. The chisel is not as precise as the planer, and it did dig into the wood from time to time. Luckily, any damage is superficial and about to be covered by fiberglass and resin.

With the sides scraped, I stuffed the ends of the frames with chop strand mat to help hold more resin and aid in the bonding process that will follow. The gap that was created between the outboard frame and the vertical batten was filled with chop strand mat. If I did not fill this void with CSM, water and dirt could accumulate here and it would be harder to keep clean. It would also drastically reduce the bonding surface area which in turn would reduce the bond strength of the frame. By filling the void with CSM, resin will be held in place and this void will become a solid block of plastic that will bond the frame to the batten, as well as the rest of the bulkhead. This will provide a very strong bond that will be able to support the forces and stresses that will be placed upon it when we begin pumping 1 gallon per stroke!

The pump was test fitted multiple times to make sure that the bolt holes still line up with the frames holes. If I were to screw the brass angle brackets into the wrong hole, the measurements between the bolt holes would be off and would not line up with the bilge pump. Each time I removed and installed a frame, I would test fit the pump to make sure I was in the correct hole. 

Now that all the frames are in position with chop strand mat squished in the void between the frame and the bulkhead, and the pump has been reinstalled for a test fit, it is time to finish up the minor details. The brass angle brackets came with brass screws for installation. These brass screws have served their purpose as a cheap, temporary fastener. Repeated installation and removal can wear the heads of the phillips screws, so using the free screws removes any worry about wearing the heads during the fabrication process. With everything finished, I switched the screws from brass to stainless steel.

These small stainless steel screws will serve as a direct replacement to the brass screws, and since they will only be installed once, they will have fresh heads and no chance of stripping or wearing. Stainless steel is really strong when using small screws like these, but they can suffer from crevice corrosion when encapsulated within the fiberglass layup that will follow. This is ok, as the screws are only needed for initial support of the frames. The real strength comes from the bonding that will follow. While the screws will not offer much strength, stainless steel screws are still better than brass screws in boat construction. The ideal metal for marine fasteners would be bronze, as it is strong and does not suffer from crevice corrosion. The problem with bronze is it is not as strong as stainless steel, so the fasteners need to be larger for equivalent strength.

It all comes down to compromise, tiny and strong but corrodes (stainless steel) or large and strong (bronze). Since these are only required for initial stability, stainless fasteners will suffice. If the frames were to rely on the screws for final stability, they would need to be up-sized and bronze would be the ideal material.

Up next, we will bond the frames to the bulkhead using fillets and tabbing for a full fiberglass job.