1987 H31 : water trapped between hull and liner

Aug 16, 2014
7
hunter 31 Redwood City Marina
I have been battling some foul odors on my 1987 H31. First I thought it was the head, but I have checked everything and no issues there.

After some google searches, I now believe I have rotten water trapped between the hull and the liner.
  1. Any recommendations on how to flush this out?
  2. Once it is gone, any ideas on how to find the source of the leak?
Thanks!
-- Erik
 
May 24, 2004
7,129
CC 30 South Florida
That is a common occurrence especially in older boats. You have rain, wash water, sea spray, packing gland drip, water tank and plumbing. Most leaks are small and hard to trace. Eventually it all flows into the bilge and by observing how quick or how frequent the bilge fills it may give you an indication of the magnitude of the problem. There are more than a handful of gallons trapped in the hull between the stringers and with the boat at rest they just stay there and fester. When you put the boat in motion in heavy seas and heeling under sail some of this water will get dislodged into the bilge. The smell is usually contained by the liner and it should not be any worse than what you get at the bilge water. If the smell on the boat is really bad then check for a dead critter that may have gotten in the boat. Opening up holes in the liner to pump the water out just lets the smells flow into the cabin. You can use a solution of chlorine in clean water and dump it into the hull. Turn off the bilge pump and go sailing. Turn the bilge pump back on before heading in and repeat the procedure a few times. That should kill some of the odor producing bacteria. As far as tracing leaks start checking the portholes, hatches, around any and all fixtures on deck and cockpit. If all fails, just take a trip for a week and by the third day at sea you will not feel any foul smell until you get back to land. Good luck.
 
Aug 16, 2014
7
hunter 31 Redwood City Marina
Thanks Benny!

You write "You can use a solution of chlorine in clean water and dump it into the hull.". How/where would I do that?
 
Dec 2, 1997
8,708
- - LIttle Rock
A wet dirty--as trapped water is bound to become--bilge is a primordial soup that can make a whole boat smell like a swamp or even a sewer, and it doesn't take any dead animals to do it. There SHOULD be adequate limber holes in stringers, but not all production builders can be counted on to reliably put them in. That makes flushing out trapped water very difficult, if not impossible. Just dumping bleach into the mix is not the solution.

Creating access to the bilges is only good solution. That requires installing a couple of hatches (something else that few production builders ever do, but should) in the cabin sole to provide the access needed to keep the bilges clean. When I restored an old boat, one of the best things I did was put a 12" wide hatch over the centerline that ran almost the entire length of the cabin, breaking it up into 3 sections lengthwise to make it manageable to lift out. Countersunk pull rings left no "toe stubbers" in the teak parquet sole. That gave me access to the entire bilge. You may not need anything that long, or two separate hatches might work better on your boat. Cost isn't pocket change, but it's not outrageous either...and a PERMANENT solution to a problem that not only ruins life aboard, but can even have health implications if you're allergic to molds. It's an improvement that can even value to your boat, if not in actual dollars, in a lot more "saleability" than a boat which stinks has.
 
Last edited:
Sep 4, 2007
764
Hunter 33.5 Elbow, Saskatchwen, Can.
Erik
I'll jump in here before any of the other 31/34 owners do. Lots of us have had this same problem and what we've done is cut out the false bottom in the bilge. This opens up the bilge to be pumped out and remove some of the old rotten wood under the liner around the bilge. If you do a search on this site you should find lots of posts.
 

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Aug 16, 2009
1,000
Hunter 1986 H31 California Yacht Marina, Chula Vista, CA
On my 86, water from the engine compartment does not drain directly into the bilge but seems to get into the liner on the starboard side. It is supposed to exit into the bilge from a hole approximately in the middle of starboard settee, and it will if there is enough water in there, but far from completely. I open the bilge and stick a hose into that hole to pump the water out at the same time sucking out whatever is under the sole. For some reason the slope of the liner under the sole is no longer [if it ever was] conducive to routing all the water to the bilge.
 
Aug 16, 2014
7
hunter 31 Redwood City Marina
Isn't it problematic to cut out the false bottom of the bilge? That is where I have my floater switch and bilge pump sitting.
Wondering if cutting a couple to 1/2" holes in the bottom of the bilge, and then empty out trapped water with a pump/hose would do the trick? When done, seal up the holes again? Or put in rubber plugs so I can easily do it again.
 
Feb 14, 2014
7,399
Hunter 430 Waveland, MS
I now believe I have rotten water trapped between the hull and the liner.
I will give you another thought. The short version...

Hunter assemblers evidently used scrap teak or other wood veneer to shim items on their irregular shaped/non-leveled fiberglass hull and items, such has my hold tank, to level them.
Normally dry liner, bilge flow was under this hold tank. Years of dirt, spider dung and "crapite" restricted this drainage path and held water.
Guess what?
That "held water", under the hold tank, soaked and begin to rot the shimming wood.

The smell was transient, because that drainage path would slowwwwwly leak and dry, and the transient puddle was not visible under the hold tank.

We have removed, with great difficulty, piece by piece, of the rotting shim wood.
Smell 99% gone and drain to bilge free flowing again and leak source found and soon to be stopped.
Jim...
 
Jan 24, 2009
450
1981 Cherubini Hunter 27 Shipwright Harbor Marina, MD
Just wondering if the same situation exists in the early 80's 27' Cherubinis.
Yes, my '81 H27 has the same kind of issues. The interior is built in a separate mold from the hull and there is a space between where the bilge pump sits and where the water actually collects. Pull up the cabin sole and stick your finger in the hole in the stringer at the aft end and you may feel water. You can fit a hose in there and pump the water out, but the suggestions to open it up will give you better access to it. It's on my list, but I want to search the site and fully understand what I'm doing so I don't cut a hole in the bottom of the boat while I'm at it. :yikes:

(And yes, I know I did it :hijack: )
 
May 24, 2004
7,129
CC 30 South Florida
I do like Peggie's solution of reconfiguring the sole and adding additional hatches providing access to the inside hull but for those on a budget or looking for a simple remedy that might not be the best option . Some will cut the liner at the bilge to be able to extract the water under it but that does not solve the problem of fouled water that is trapped away from the bilge area and it can expose the odors to the cabin atmosphere. I do not have an overly sensitive nose and have had a fairly good experience in suppressing odors by adding a chlorine solution and putting the boat through its paces and trying to mimic a washing motion to mix the old stuff with the new and latter releasing the excess. I dump around 10-15 gallons of solution at various places in the inside hull and shut off the bilge pump. The cockpit lockers usually have openings, under the Vberth and even where the packing gland drips. I do not think there is a sure-fire solution to the problem just various different remedies and you can pick and choose from the suggestions the one that appeals to you the most.
 
Sep 2, 2011
1,041
Hunter 27 Cherubini Alum Creek State Park
Yes, my '81 H27 has the same kind of issues. The interior is built in a separate mold from the hull and there is a space between where the bilge pump sits and where the water actually collects. Pull up the cabin sole and stick your finger in the hole in the stringer at the aft end and you may feel water. You can fit a hose in there and pump the water out, but the suggestions to open it up will give you better access to it. It's on my list, but I want to search the site and fully understand what I'm doing so I don't cut a hole in the bottom of the boat while I'm at it. :yikes:

(And yes, I know I did it :hijack: )
I don't have to stick my finger in that aft limber hole. I can see the water draining out and into the aft bilge. I've used a pump and long hose to get some of it out, but a hidden leak is still feeding it. As soon as the weather breaks here in Ohio, I'll be rebedding the stanchions and ports.
 
Jan 24, 2009
450
1981 Cherubini Hunter 27 Shipwright Harbor Marina, MD
Sounds like you read my to-do list, I started on tightening stuff last fall and will work through everything else this spring. "Leak free" is becoming a quest at this point.
 
Feb 14, 2014
7,399
Hunter 430 Waveland, MS
I'll be rebedding the stanchions and ports.
That is my leak. Dock helpers have grabbed two specific stanchions to pull and drag a 13 ton boat to the dock. Wiggling over the years has broken the 5200 seal.
Jim..
 
Jan 22, 2008
1,654
Hunter 34 Alameda CA
Isn't it problematic to cut out the false bottom of the bilge? That is where I have my floater switch and bilge pump sitting.
Wondering if cutting a couple to 1/2" holes in the bottom of the bilge, and then empty out trapped water with a pump/hose would do the trick? When done, seal up the holes again? Or put in rubber plugs so I can easily do it again.
Not problematic at all. The bottom of the pan liner provides no structural strength to the boat. All that happens by removing it is to move the bilge pump and float switch to the actual bottom of the boat. This will get rid of the smell, rotted wood and inability to keep a dry bilge (provided the leaks can be located). One source is from the dripping packing (if you have the original flax type). Retained seawater will grow critters that die and stink.

Here is the link to more discussion on the subject specific to our boats. Many have done this mod with positive results.

http://forums.sailboatowners.com/index.php?threads/hidden-bilge.146867/#post-970990
 
Aug 16, 2009
1,000
Hunter 1986 H31 California Yacht Marina, Chula Vista, CA
Unless I am reading this wrong, Allan's solution is premised on the assumption that the liner is sloped so the water from its various places ends up in the "true" bilge? On my boat, this does not seem to be so. If I have allowed water to build up in the engine compartment [which seems like the only source because if that is dry, so is everywhere else], it pools in the liner under the starboard settee and the salon table. Some not so elegant fiberglass or resin repair to the bilge makes it almost certain that at some point in the past the PO hit something with the keel that distorted and pushed the bilge up. I haven't had the boat out of the water yet to see what the keel/hull joint looks like, but my diver says he does not see any problems. I have not yet devised a solution for the fact that it takes somewhat more water than it should before the liner drains into the bilge.
 
Jan 24, 2009
450
1981 Cherubini Hunter 27 Shipwright Harbor Marina, MD
When I had the drivetrain aligned, etc., we went with dripless teflon packing and I no longer worry about that as a source of water, any water that I used to get runs under the engine and down into the bilge. You might look into the dripless packing as a solution if you have an otherwise dry boat, along with whatever other issues you have.
 
Aug 16, 2009
1,000
Hunter 1986 H31 California Yacht Marina, Chula Vista, CA
Like you I had a dripless seal and never had any water under the engine. Then I went through a long restoration interval in which I made the mistake of not starting the engine. The seal pitted and began to leak. I have to haul out for bottom paint anyway, so the dripless shaft seal, cutless bearing, and possibly the shaft flanges will be replaced before the shaft is aligned.
 
Jan 24, 2009
450
1981 Cherubini Hunter 27 Shipwright Harbor Marina, MD
I also put in new engine mounts, cost about $200 for 4. That smoothed things out and helped with getting it all back in alignment.