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. 

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