Water leak in Forward Bilge 1994 370 EC

[PlayDate]

This one has me stumped to the point where I may have to drill holes to find out what is really going on.

Four days ago I pulled the hatches in the Salon on my boat and found 1.5" of water in the bottom of the forward bilge which is not supposed to have any water in it. My first suspect was the Shower sump which I drained and removed the wet carpet (yes it was carpeted) from the bilge. In this bilge there is no bilge pump and no exit/entrance for water. 2 days later there was another 3/4" of water in the bilge which I removed again. 24 hours later there was another 1/4" of water which I removed and shot the following pictures.

The water is coming in from two points: 1) the part of the compartment closest to the bow 2) the point identified in the pictures.

Some background:

-The fresh water tank is located in the stern and is empty.
-The porthole windows are not leaking
-The windshield gasket was replaced and resealed last year
-There is no access to the compartments adjoining or the space under this compartment
-The water does not have an odor
-The bottom was completely redone (soda blasting, barrier coat and paint) last year

That leads me to suspect:

-The bow thruster has leaked water into the space between the hull and bottom of this compartment and that space is full of water. To get a view of the Bow Thruster tunnel, I have to remove the HVAC system from the bed platform which is a pain.
-Rain water has leaked into the compartments adjoining this compartment (which are inaccessible)

Before I started drilling, I thought I would throw it out to CSR for your thoughts.

My plan is to drill a small hole into the floor of this compartment and see if water is present. If it is, I plan on pulling the HVAC unit to inspect the bow thruster. If it is dry, then the plan is to pull the carpet and drill into the adjacent compartments to see where the water is coming from.

JD

 

[1956olds]

Have you checked to see if your anchor locker drain is plugged with debris or bugs?Possibly the horn mount screws?

 

[fwebster]

I don't know if I have an answer, but I do have some observations that may help your thinking process.

1. It is possible for the side windows to leak and the water not be visible inside the cabin until it reaches a low point. THe headliner/wall covering is vinyl so water can run down the inside of the wall covering until it runs out at the bottom of the wall covering…the inside remains dry to the touch.

2. Water can enter around a stanchion base and run down the inside of the hull and get under the false floor where it remains until the level gets high enough to run out of a screw hole or bilge coat void.

3. An aftermarket thruster install is a more likely cause. The people who do installs outside the factory are now known for building structure, just for cutting a huge hole in a boat and covering up the ends. We have seen 4-5 expensive boat whose owner wanted an aftermarket thruster installation, only to deal with a serious leak 2-3 years later.


Please post what you find…….some of us may get a brainstorm later!

 

[PlayDate]

Frank,

I agree with your view on the bow thruster which was installed 5 years ago. I rebed the stanchions probably 7 years ago with 5200 and they don't give at all. If memory serves correctly you had a 370 and while I agree with your comments about the portholes, it is just too much water when it hasn't rained for a couple of weeks. I know that drilling a small hole in the bottom of the compartment will prove it one way or another. What drives me crazy is that there is no way to inspect the area beneath the compartment and that if the front bilge filled with water it would have not place to go. The way the bilges are designed on the 370 EC is that the entire salon would have to be filled with water before water found its way to an engine room bilge pump. It seems crazy.

Thank you for your comments. Also those of 1956olds. Once again, the amount of water and lack of rain just points to something else.

I'm heading down tomorrow am to check the boat again and will post what I find. I'm travelling this week so I plan on putting an extra pump on the floor of the compartment in the advent it continues to accumulate water. That way I can sleep at night. if it is the bow thruster, I have to find where the leak is before I have the boat pulled.

JD

 

[PlayDate]

Update:

Some good news. After drilling three 4.5" holes in my boat I found that the water was not coming from the bow thruster.
As you can see from the photos, the space between the bilge floor and the hull is filled with water. This space is also filled with what appears to be floatation foam. I dug out the foam by hand down to the hull. The reason for two holes is that there is a structure beam between them running the length of the locker basically creating two areas under the floor. I used a hand pump to move the water from the openings into the sump which pumped it overboard. I have ordered two small automatic bilge pumps for the openings to deal with water and any future water.

The hole by the platform bed provides a view of the hull as it runs back toward the stern. It is located between the bow thruster and the front of the locker in question. After digging thru 18" of foam, I reached the hull which was completely dry which was welcome news. I put a deck plate on that hole and reattached the carpet.

So where is the water coming from? I suspect the port windows. What appeared to be a lot of water is a result of both sides of the boat leaking water into the compartments next to this locker. The water builds up and leaks into the space between the hull and the bottom of this compartment. When the water filled the space....it leaked into this area. The new bilge pumps will control the water until I can rebed the port hole windows.

 

[tas]

John,

I am wondering what your findings were on the source of the water from this thread. I have encountered a similar problem with my 95 370 Sundancer over the weekend. The water is an amber color and comes through the forward port corner and the aft stbd corner of the salon locker floor at the rate of a 1/2 pint or so an hour.

I have checked all of the through hulls, the a/c lines, f/w lines, and from what I can see, any window leaks wouldn't have access to that far down in the hull and would rather wick down to the floor and soak into the carpet. Unless I get some different counsel, I have to assume I hit something and punctured/cracked the hull under that
area?

Anyway, ideas or findings would be appreciated.

Todd

 

[PlayDate]

Two leaks which were not obvious:

1) The overhead hatches needed to be rebedded. What happens if you pressure wash your boat as I do once a year is that you can displace the caulking between the hatch and the deck. On our boats those hatches were hand cut and the overlap of the hatch is minimal in some spaces. What happens then is that water enters the cored space in the deck, starts turning the balsa wood to mush and keeps on going until it finds a way out. Usually it heads for rub rail seam but will exit anyplace there is a porous area in the fiberglass. I believe the brownish water is a good clue that the water has passed through a cored area.

2) Several Stanchions needed to be rebedded. This was the final area to find which was not particularly obvious. I could see clear water behind the galley refrigerator which had me chasing my tail with the port hole windows. The water looked like it was coming in from the head area or the port hole windows. The windows didn't leak and there was no evidence of water any way forward of the galley. Finally, I went back to the Stanchions and the one closest to the port side shore power connections was loose. Water ran down that stanchion behind a piece of hull structure and exited there into a channel behind the refrigerator and then down to an inaccessible space below the galley locker. It filled that space with water which necessitated putting in two access holes to pump it out.

This particular stanchion is located a key water point which all the windshield water runs off from. While it was loose, the amount of water hitting it was significant from the windshield drain.

Now I have a completely dry boat!

 

[PlayDate]

The mystery is finally solved. I have been chasing this leak since 2014. In 2019 after re-bedding everything again....I gave up and plumbed in two small Rule pumps to keep the water from accumulating under the galley bilge floor.

That was okay but I really didn't like that rain water was finding its way into the boat. Finally two months ago I stripped the interior and put in a couple of inspection holes. Neither showed where the water was coming from. What was perplexing was that rain and the bilge filling were not a one to one reaction. Putting a hose all over the area would not present a leak......at all.

It wasn't the bow thruster, HVAC or the water tank. When the bilge filled up.....it was 5-10 gallons of water depending on the rainstorm.

So.....this year in prepping the boat I was redoing the Isinglass and noticed an interior seam between the radar arch and the deck/hull. That seal is made of foam rubber and was cracked in pieces. Water from the top canvas drains directly down the inside of the radar arch into this seam. Alleluia! This was the leak that I have been looking for and explains why there is so much rain water and why it took a while to make it to the galley area.

Effectively the rain water went into a cavity behind the soft side panels which then made its way to the perimeter walkway deck. The walkway is balsa filled channel that surrounds the deck of the boat. This became a reservoir for the water to accumulate in and it would leak out at various bulkhead points on the port side which would then drain into the area below the galley floor compartment which was 8'-10' from where the arch opening was.

The fix was to remove the foam pieces and fill the void with 3m 4200. No more leaks.....finally.

 

[440 Jim]

Very nice!