Leaking forward fresh water tank - Beneteau 423

Dec 29, 2011
5
Beneteau 423 Houston, TX
I have a 2006 Beneteau 423 and the forward fresh water tank has developed a number of leaks in the lid (top surface) of the tank in the last year or so. These are mainly pin-hole leaks, which I have been successful at patching, but I am concerned that there is an underlying root-cause behind these problems that is going to lead, sooner or later, to a complete failure of the top surface of the tank. As far as I can tell, the top of the tank is simply marine plywood that has been glassed in and sealed to the top of the forward and aft (under the forward berth) bulkheads to complete the water tank. Does anyone have any experience with this issue and/or with replacing the top surface (lid) of the forward water tank?
 

DougM

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Jul 24, 2005
2,242
Beneteau 323 Manistee, MI
That seems rather odd. The original tank I would think would be a separate polyethylene unit.
The bow tank in my 2004 B323 is a completely self contained vessel located below the V berth.
Looks like somebody did a DIY job rather than install a replacement OEM tank. (???) Just my personal opinion.
 
Dec 29, 2011
5
Beneteau 423 Houston, TX
That seems rather odd. The original tank I would think would be a separate polyethylene unit.
The bow tank in my 2004 B323 is a completely self contained vessel located below the V berth.
Looks like somebody did a DIY job rather than install a replacement OEM tank. (???) Just my personal opinion.
The forward tank is 100 gallons capacity and appears to be built in. I have not had a reply from Beneteau as to whether this was the original plan or the specifications/build method for this tank. The aft 50 gallon tank is a self-contained polyethylene unit installed under the aft cabin berth; no problems with this one.
 
Nov 6, 2006
9,885
Hunter 34 Mandeville Louisiana
My buddy's 42 Beany Toe center cockpit had water leaks in the forward tank, but not through the top. We had to open it by cutting an access hole in the top .. Found sealant leaks in the sides of the tank where the liner was sealed to the hull to make the tank .. Looked to me like normal hull "working" in a seaway had opened the bottom corner seam.. Got some food grade sealant and gooped the thing up as best we could.. No problem in ten years so far.
I found it strange too that the tank was using the liner and hull for containment, but I know some manufacturers did that (Hunter 40 and 31 of the '80s) In the picture, you can see the top off and the baffle and the inner surface of the hull. No problems with the cover leaking. You can see the white color of the core but I don't remember exactly what it was.
Photo0154.jpg Photo0155.jpg
 
Last edited:
Jun 23, 2013
271
Beneteau 373 Newport
cest le bon,
WOW! With all the boats I’ve owned have never seen what you describe. Always separate tanks from any interior hull partition.
FYI my 373 has two poly tanks - one under vberth- 54 gal and one aft under stud cockpit locker - 44 gal.
This definitely sounds like a DYI fubar.
With what you describe how are fill and vent installed?
 
Jan 7, 2014
395
Beneteau 45F5 51551 Port Jefferson
I have a '93 beneteau 45f5. I have 5 tanks (maybe 4) built in to the bulkheads by the factory and one polyethylene tank in the forward berth. I have had no issues with the built in tanks. The polyethylene tank or it's hose is leaking though. Each tank has an inspection port. I have no idea why they would be leaking. If you don't have an inspection port, I would install one. Maybe you could then get some pictures of the inside top of the tank to see what's going on.
 
Mar 20, 2016
594
Beneteau 351 WYC Whitby
My boat has 2x 50 gal poly tanks ,with inspection port holes ,one under v berth and one port side of engine starboard side is 2 8d batteries
 

NYSail

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Jan 6, 2006
3,049
Beneteau 423 Mt. Sinai, NY
I have a 2005 423. The front tank while attached to the front hull is a separate Tank..... looks like it was dropped into place and attached as far as I can see. Very strange you are getting pin holes on top of the tank?? So far my tank is all good. I am considering cutting an access port on the top to be better able to clean it.

Greg
#209