49 Hull Leak

[lhulcher]

I am hoping that you can point me in the right direction to resolve a slow leak in the bottom of my 2007 Beneteau 49.
I became aware of water in my bilge last season and eventually decided the stuffing box / seal needed to be replaced. So I hauled the boat and had that done.
Water continued to appear and I spent the rest of the season trying to chase it down. Finally I removed much of the rear cabin bed structure and found a 24x6x6 cavity aft of the stuffing box. I’ ll call it a false bilge as it does not drain to the main bilge channel. It appears that there are 2 patches that were applied during manufacturing or commissioning. Both patches are cracked and leaking about 1/4 cup per week.

I am concerned about long term water damage to the hull. What is the correct resolution?

 

[Don S/V ILLusion]

looks like part of the bulkhead between the aft locker space and bilge shaft log location. In other words, interior movement of water between spaces which isn't uncommon but easily rectified. Our son had a B46 with same bulkhead configuration but no patches were evident indicating somebody goofed somewhere between manufacture and your ownership.

 

[lhulcher]

Don,
Thanks for your reply and it does look like someone goofed. I ordered the boat new from Annapolis Yacht Sales so I don't think any one else installed the patches. AYS is sending a technician to look at it and develop a repair estimate in the next week or so..........stay tuned.

 

[NYSail]

I had the same issue and have a bunch of pictures on the repair.

During manufacture of the boat, that area was a hollow cavity. Once the shaft was laid in with the fiberglass shaft tube Beneteau poured a slurry into the area that was meant to support the shaft. However the slurry was apparently ill made and when they poured it a further insult to injury they did not get the air out of the mixture so there now are voids inside. At inspection of my slurry I saw the cracks and water seeping in... When I bought the boat and was going through her I saw this area and noted the cracks in the slurry (before it leaked).

Now to the outside of the boat.... where the stern tube exits the boat and where the cutlass bearing goes in (metal sleeve) you may have noticed a bunch of sealant.... well what happens is once that sealant gets old and starts to let water in it seeps in to the boat along the outside of the stern tube, then through the poured slurry and exits into your boat.

I discovered this last season a week before I was leaving on a 2.5 week trip. Had the boat hauled. First I removed all of the sealant and ground down the area to open it up a bit. Then went inside and where the cracks were I dug deep through the hardened slurry. Not an easy job.... but went down deeps and dug out the entire cracked area. Then let it dry out for a couple of days.....

Once I did not see any more water dripping from the outside I filled the inside with epoxy.... first pour was with a thin epoxy that could seep into all the cracks, then once that dried I filled the rest with a regular epoxy. Came out solid.

Now the outside.... I forgot the name of the stuff (I can get it) but my boatyard gave me an epoxy putty that I used and built up around the area of the stern tube where it comes through the hull. I let it dry for a day and a half, splashed the boat and have not seen a drop since.

This is a not so uncommon of an issue... many people think it is just a slow drip from the stuffing box because thats were it runs down to and they move on. Took some investigating but I found it.

Greg
2005 Beneteau 423

 

[NYSail]

The crack was at the aft portion of the cavity.... if you have any questions let me know.
Greg

 

[NYSail]

I am assuming your “crack” is at the aft section of this area? I started with a drill, then used a sharp chisel and hammer to break chunks of the slurry out. I did not want to drill too deep in fear of damaging the stern tube. This slurry area supports the shaft and I am sure has significant pressure when engine is running hard. Eventually it cracks where the bad pour reveals itself.....

 

[lhulcher]

Thanks for the great commentary and supporting pictures. The area in question is very similar on my 49 just longer, about 24l x 6w x 6d. And the crack is aft with another one developing 4 inches forward. I had the stuffing box seal and cutlass bearing replaced last summer which required removing the shaft. Perhaps the sealant was compromised further aggravating the interior cracks.

 

[NYSail]

That makes sense..... that is only a portion of the "cavity". Heading forward there is another 6 inches or so. It starts a little behind the dripless vovlvo shaft seal and anges down till it exits the hull where the cutlass bearing is. Once the sealant is compromised the water can sneak in. And again, that slurry stuff has to withstand a lot of force when the shaft is spinning to keep it from wobbling. Overall an easy fix but tight working area.... my inverter sat on a shelf above this area so I had to remove it to see everything.

Any questions just ask!

Good Luck!

 

[Mechone]

Had the same issue 3 years ago, and so have allot of others , they fill the cavity at the factory with vinyl ester resin,
as it cools it shrinks and cracks down to the tube they put a bead of 5200 where tube comes out . When this fails water goes in along the tube and up thru the cracks .
I ground out the cracks with oscillating tool, mixed up some thickened west epoxy with 404 and poured it own the cracks . I also removed the gel coat about 2 inches either side of the crack ,so after pouring I put a 2 inch wide fiberglass tape over the crack.
Now the outside cleaned it out with a dremal , filled it with thickened west and then glassed a nice radius using fiberglass tape. By the way my tube is fiberglass ,not stainless ,earlier beneteaus the tube was fiberglass. No leaks for 3 years
I was told the stainless tube came from Moorings request as too many renters were backing over rope towing tenders wrapping prop and cracking fiberglass tube

 

[lhulcher]

I might be one of the guys that caused Moorings to request stainless tubes! Seemed to be a common issue on BVI charters.
Your comments about vinyl ester resin and 5200 are encouraging me to do this repair on my own. How far down can I grind down before encountering the tube?

 

[Mechone]

I might be one of the guys that caused Moorings to request stainless tubes! Seemed to be a common issue on BVI charters.
Your comments about vinyl ester resin and 5200 are encouraging me to do this repair on my own. How far down can I grind down before encountering the tube?

I just v opened the crack about a 1/4 inch then mixed up west with some 404 not too thick and let it go right into the crack, or get some syringes large ones and inject the epoxy into the crack ,if I remember that's what I did