Trojan Boat Forum

I was surprised to find I had four through the hull fittings that were molded into the fiberglass. Two on the Port and two on the Starboard side near the stern. We are out of the water right now and I am inspecting all the trough the hull fittings. I was surprised to find a through the hull fitting near the bow on the bottom of the boat! It is not the rode drain. I am not sure what it is there for. Another msytery to figure out. I am surprised at how many through the hulls are on the boat. I must figure out what they all got to and check the clamps on all of them.
Anyway can't wait to Striper fish.

On our 73 F36 I have at least two forward through hull fittings that I can think of.. One is for flush water for the head (I have capped that one and changed to use fresh water, with and anti-siphon valve, for the head). The other is for raw water for the forward AC unit.

The next two back are intakes for the engines.

Then just aft of the prop shafts is an intake for the genny and then another AC intake.

All the holes below the water line can scare the crap out of a guy. I guess that is why I have 6 bilge pumps on board that run from 3 seperate battery banks!

are we talking ''thru hull fittings'' or ''seacocks''? there is a difference. a ''thru hull fitting'' is normally above the water line and used to discharge either water from the decks, as in scuppers, a/c raw water pump
discharge, galley/sink drains, manual/auto bilge pump discharge, engine raw water exhaust discharge from genset etc.... these cannot be 'closed off'. now, the seacock, which is used below the waterline, can be closed off and is used for intake and discharge of toilet (mine, since it was built before 1978) engine/genset raw water intakes and a/c raw water pump intake. thru hulls and seacocks are two different animals. which ones are we talking about?

My mistake, you are right! I was talking about both, But let me clear it up. The forward seacock is the one I am wondering what it is for. Definately a seacock because it is below the water line. Most of my seacocks are located in the engine compartment right in from of the battery bank. Some of them are capped and some used. But the one that I do not know what is for is located close to the bow. It does not have a strainer on it. It could be for the toilet but it is small. We use pump out and do not discharge. I shall investigate it. I believe I will see it when I open up the forward floor hatch. I also have some seacocks located in the cockpit area for some pumps serving the heat pump and a saltwater bait tank.
The through the hull fittings are located on the sides of the boat and there are plenty of them. I believe around 7 on one side and up to 6 on the other side.
Our 11 meter only uses one Heat Pump. Thanks for the correction.

It sounds like you are describing the hull drain plug. This plug is removed when the boat is pulled for storage. My drain plug is a 1/2" bronze plug screwed into a bronze through hull fitting. It is located in the forward state room just behind the V bed. With the plug out, water can drain. (Batteries are remove for Winter storage, so pumps don't work.)

Hi jerry, My parents belonged to the Chicago Yacht Club. I Loved it. I actually have been around Lake Michigan atleast 2 times. I have a lot of respect for Lake Michigan, it can get rough in no time. I
I don't think that is the outlet for it. There is no plug in it. I will check and see it it has a shut off on top or is capped.
Raining here today which has set our plans back to get more work done on the boat. But tomarrow we will try and proceed.
I appreciate all the ideas you all have given me. Lots to think about.

Okay well I think everyone is talking about the fittings through the hull below the water line. A seacock is a valve attached to a through hull and usually, but not always, bolted through the hull and/or screwed to a wood block molded with fiberglass into the inside of the hull. A through hull can be of the mushroom variety or have a scoop strainer that faces the bow and scoops water up into the fitting while straining out seaweeed etc.

A true seacock is attached inside to the hull and made part of the hull so in case the through hull fails or is damaged, the valve can be shut off so you don't sink.

If you have just a ball valve attached to a through hull and it is not bolted to the through hull or made part of the hull then if the through hull is damaged then you can still sink even if you shut off the ball valve.

I have these below the water line fittings.

Bow-drain plug mushroom variety through hull

Midship- Seacocks for each engine cooling water intakes with scoop strainer

Stern - Seacock with through hull of mushroom variety for Air conditioner intake water.

I can see what you are saying. I have both on the boat. I have not had time yet to check them all. All the through the hulls on the outside look good and sound. I have not checked all of the inside ones yet.
I have to work on my props. The have some play in them so I plan on putting another washer on the shaft to help keep the locking nuts from backing off. ooops, I think I will put a locking washer on there instead of a plain washer.

Thanks Tad, I was going to reply as yours but I'm eating ribs and have a mess on my hands. One hand typing is not getting it.

Scott

I have found a through the hull fitting that is capped off. It is near the forward bildge pump. I decided to take the cap off and check it. I found it was not bonded. . It will be when I replace the cap and bond the fitting. So I did find the mystery through the hull fitting. It is not used.

My forward through hull is not bonded to the hull with a seacock. Mine just is a through hull and has a female thread inside that has about a 5/8 male pipe thread plug in it. It gets removed from the inside of the boat in the winter for storage and gets installed before launch in the spring.

reelfishin wrote:I have found a through the hull fitting that is capped off. It is near the forward bildge pump. I decided to take the cap off and check it. I found it was not bonded. . It will be when I replace the cap and bond the fitting. So I did find the mystery through the hull fitting. It is not used.

Since this through hull is not connected to anything that could supply an electrical current it does not need bonding.
It is only used when the boat has been hauled and blocked for dry land storage when it should be opened to allow any water that might enter the hull during storage to flow out.

It was bonded at one time. I will investigate some more then. Maybe it does not need to be bonded. That will make it easier. Thanks

I think we are talking about two kinds of bonding. Electrical and physical.

In my post earlier, I referenced the bonding of the seacock to the hull. This was a physical bond and not electrical.

If the fitting does not have any connection to the power circuitry or to ground and is of a relatively low potential (I'll explain that later) it does not need to be electrically bonded.

So with that said, most underwater through hulls are made of brass (red not yellow) or bronze. These metals have a lower potential than say zinc.

By potential, I mean potential to allow current or electron flow, thus causing corrosion due to the plating process or metal electrons flowing away from your fittings to a ground source somewhere in the water.

This mainly happens when there is a bad power situation at your marina with a poor ground or improper wiring. Stray current can't find a good ground and so it searches through your boat and out the metal parts sticking in the water for a good ground source. In that process, positive electrons flow from the tips of anything metal to a ground source somewhere else in the water. That is why the zinc fittings are put on propeller shafts and trim tabs so they get eaten up before the props, tabs, or fittings.

first off i hope no one is eatting or drinking when you read on first none of my thu hull fittings are bonded oh wait you cant bond plastic yes below the water line i have 3 thu hull fittings that are plastic the scoops are bronze with pvc ball valves scarry i know i dident worry about them this year due to other shake down items like getting the moters to run past 1200 rpms that prob is solved new 8 deg wedge plates ( thay were missing)and gaskits so this winter lay up im pulling all thu hulls and installing new bronze mushrooms and new sea cocks and thay will all be bonded it is truly amazing what people will do to get bye