Smelly Boat? - One more place to look!

Greetings,
Although I have seen this topic referenced in several indirect postings (COMODAVE and Ttsaang), I felt it was worth attaching to the "Smelly Boat" search as this is truly a new "place to look".

My wife and I found a well worn but reasonably good shape GB32 a few years back and after a season of reading "smelly boat" books and postings, (thanks Peggy!) we had some pretty spic and span bilges, (all the potions....) new head hoses, sealed off head raw water intake, pulled up shower pan, bottom of hanging locker (a bear), chain locker and scrubbed every below deck surface, ultimately still ending up with a consistently REALLY SMELLY boat... kind of that seawater, diesel fuel, head discharge combo that could be a dead animal.... When we purchased the vessel, it was in cold weather and on the hard. Contingent sea trials in the spring noted a few mechanical elements that were quickly remedied but also a faint odor that would need to be pursued..... we also noted a variety of "odor eater" type approaches around the cabin... various and many "air fresheners".... after a season, we were contemplating the approach; "if you cant find it..... sell the boat".... it was most ghastly after being out on the water and once we pulled into our, or a transient dock...pheeew!!!!! I upgraded our bilge blower but the odor being removed did not make us popular with our neighbors...... So.... in the pursuit of eliminating standing water as an odor source, as the GB32 has a flat bilge pan, I figured I would sink a shoebox sized "sump" just under the driveshaft, aft of the engine (good access). I do recall the moment, with grinder in hand, I plunged the first cut into the flat bilge floor and ended up cartoon style, with a stripe of black slime, from my knees to the top of my head..... I immediately left the boat, found my wife and as I got within 10 feet of her, she exclaims..."You found it!" The hidden sludge tank....... On many vessels, apparently the keel area can be solid with ballast, meant to fill with seawater in some cases, or in our case, meant to be dry, but sealed from access.... after cutting my access hole, I pumped approx. 10 gallons of this evil sludge from my hollow keel (it was filled to the top), followed by 3-4 hot water rinses... and topped off with a 3" access port (I still installed my sump).

The smell is gone, especially with all of the prior cleaning of the search process! This area must have gradually filled through the years via various channels, but still without any really access. When we went out for a spin, it would just create such pressure in that below area, fumes would rise into the bilge and remainder of the boat. Had we not found this location, it would have been tough going. Apparently this is not uncommon... but with a sealed space like that, I would think that access would be available... now there is.... Thought worth sharing...

Excellent Recap

Thank you for making me smile!

Great work, I am currently doing same thing, only my area is forward of the engine. I will do a new thread when I'm done.

Do you have any pics of it completed? I was planning on doing sump but wasn't sure if I should put I water tight access from the bilge to the keel.

I am sure you are relieved as well as a feeling of accomplishment for not giving up. I have a GB copy and it also has a flat bilge floor. So far no smell but I had thoughts of what might be below. Thanks for the tip.

We used to have an F32 Trojan that had a hollow keel. The trapped water smelled worse than a holding tank. Cut the top open and cleaned it really well and smell was gone. Congrats on finding your smell.

In the mid '90s I had a call from the owner of a steel hull trawler who'd attended one of my seminars, asking me for help getting rid of a persistent odor in the boat...not strong, but enough to be really annoying. They'd already ruled out hoses...the bilge was dry and clean enough to eat off of...ran every possible source I could think of by her, she ruled out every one. Finally here was only one possibility left: trapped water in an inaccessible area somewhere. She assured me there was nowhere water could be trapped. I had to admit I was stumped.

A couple of months later she called me again. "You were right, it was trapped water. We'd seen some corrosion in the keel and had the boat hauled to investigate. When the yard drilled into the keel to find out how deep the corrosion was, about 20 gallons of water poured out that was so foul everyone had to leave the area." It seemed that the keel bolts had allowed any moisture in the bilge--even humidity, condensation, etc--to seep by them into the keel, keeping the bilge dry, and was almost certainly the source of the corrosion. Once all the foul water was gone and the keel bolts sealed, so was the odor. Had they not needed to investigate the corrosion, they might never had found it.

--Peggie

It is surprising how bad stagnant water can smell.

Thanks for sharing this story!
My current boat does not have a keel -- but if a keeled boat ever pops into my future, I will never forget this!

Great info Patience - thanks for this. I, too, have been wanting to make a sump.

Nick

The Green boat had foam in the keel covered with fiberglass. It too had the most disgusting odor from water leaking in but not able to get out.

The recurring theme seems to be it must be dry!

Rob

Reading this thread makes me feel lucky... My boat has a keel, but it's not ballasted and not overly deep. Because it's not overly deep, they didn't cap off the top but just left it open, so the keel just serves as a sump for the bilge (with nowhere for water to get trapped).

Comodave said:

It is surprising how bad stagnant water can smell.

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Apparently you've never been near a swamp when the weather is hot. "Pond scum" on the surface seals the water,. Or smelled a wet bilge or sump that's in need of a serious cleaning.

Odor is the result of organic breakdown in anaerobic (without oxygen) conditions...it cannot occur in an aerobic (oxygenated) environment. That's why running streams never stink and the reason why sewage treatment ponds always have a big fountain in the middle of 'em and decorative water elements in malls and office buildings are always running water.
And why venting that allows a holding tank to "breathe" or aerating it is essential to eliminating odor from it...it prevents odor from occurring.


I discuss all this in detail in my book, btw.


--Peggie

My lowest bilge can get stale; some water gets in but not enough to run the bilge pump very often. My solution is to toss a couple of bromine tablets down there. The kind they say to use for my hot tub. Apparently they're better for the components in the tub, like pumps and heaters, than chlorine.

Thanks all for the positive feedback here and identification with this issue. As there is a noted interest in the sump concept, I'll get out a few photos in the next few days (Zipper door is frozen shut!)
Regards, Bruce

GB32Patience said:

Thanks all for the positive feedback here and identification with this issue. As there is a noted interest in the sump concept, I'll get out a few photos in the next few days (Zipper door is frozen shut!)
Regards, Bruce

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This is the first year we have had our boat in heated storage, it is wonderful.

HeadMistress said:

Apparently you've never been near a swamp when the weather is hot. "Pond scum" on the surface seals the water,. Or smelled a wet bilge or sump that's in need of a serious cleaning.

--Peggie

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I try not to let my bilge get in that condition. The F32 was a new boat to me and I don’t know how the PO lived with the smell. My wife certainly would not have.

Our new boat, a Formula 41PC, has a huge sump that is fed by the shower, 2 A/Cs, 2 sinks. It is falling apart. Today I started ripping it out, what a PITA. The bilge is dirty and greasy, not too bad but way beyond what I like. So tomorrow I will break out the Extreme Simple Green to get the heavy grease cleaned up. I had a new sump box made out of 1/2” plastic welded together. It will have 5 inputs and I will be using a Whale Bilge IC pump to evacuate the water. It is the last big job for this winter. I still have several other jobs to finish up. Then we will be ready to launch!!!

Why do the sinks drain into a sump, Dave? Gray water can legally be discharged directly overboard in all US waters and the Canadian side of of the Great Lakes except for a very few closed inland lakes and the FL National Marine Sanctuary.


--Peggie

HeadMistress said:

Why do the sinks drain into a sump, Dave? Gray water can legally be discharged directly overboard in all US waters and the Canadian side of of the Great Lakes except for a very few closed inland lakes and the FL National Marine Sanctuary.
.

--Peggie

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My 1981 IG36 had an OEM grey water tank around 10L capacity serving shower,sink,washbasin, fitted with a flipper type switch prone to gumming up and an OEM US made pump capable of suck starting a Harley Davidson. No idea why. Happily my Integrity 386 (based on IG36) drains overboard direct,though the shower has an easy to access pump out box set directly under a grille in the floor of the shower.

HeadMistress said:

Why do the sinks drain into a sump, Dave? Gray water can legally be discharged directly overboard in all US waters and the Canadian side of of the Great Lakes except for a very few closed inland lakes and the FL National Marine Sanctuary.


--Peggie

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From what I've seen, Formula likes to reduce the number of discharge thru hulls. Either via manifolding or sumps depending on the situation. They probably figured it was easier to just plumb them to the shower sump vs routing to another thru hull for overboard drainage. Being an express style, it's also possible some of the sinks aren't much above the waterline.

Yes, Formula went to a lot of extra effort to reduce the through hulls. They have a unique discharge for the bilge pump and A/C cooling water. They have one big through hull with 4 inputs to it. I think it is a custom bronze fitting. But I am adding a 1.5” vent for the holding tank on each side so the holding tank will not be anaerobic and a 1” discharge for the sump box. The sump box is 20”x8”x8”. I am going to put a Whale Bilge IC pump in the sump.

Where is the holdng tank located in the boat, Dave?



--Peggie

In the stern behind the engines.

I was afraid that's where it is. You're planning to run two vents, one to each side of the boat? If so, either put the thru-hulls at least 2' above waterline with oversized clamshells over 'em, facing the "wrong" way to act as air scoops when the boat is underway or on an anchor, or use one vent with with an aerator in the tank.

I'm afraid to ask how far that puts the tank from the toilet what the route will have to be. Send me a PM if you want to discuss.

--Peggie

Yes, it is indeed a long run to the tank. It has a Vacuflush head. Not my favorite. Eventually I want to replace it with a Marine Elegance. The discharge run will be a bit shorter then and all the maintenance items moved into the head instead of buried in the inaccessible area that it is now.

Additional Sump Detail

Several expressed interest in the sump and access port I installed as a result of my adventures. Here are a few shots. Not true finished glass work (West Epoxy and cloth) but it did the trick for me. The bronze female gets capped and inspected at seasons end to see if water intrusion (so far, a small amount) and pumped dry. The "sump" you can see that I essentially used the curved sides of the keel as the sump sides and bulkheaded forward and aft. I pulled the pump for clarity (small rule 800). Currently manual operation as I have the big RULEs up forward on float switches but unfortunately a little tight in the sump for a float switch so may look into an integral switch model.... open for questions/comments/directionView attachment Sump Image 1.pdf

View attachment Sump Image 2.pdf

View attachment Sump Image 3.pdf. Hmmm... don't have the skills to insert image (looking for a url?) so attaching images.

The sump looks great and should be very useful. Great job. I suppose yours was like mine it. Just long and flat with no where in particular for water to go if it gets in there...lol. Having the sump area should certainly help. One thing that may work well is a dry bilge setup instead of a standard bilge. They really work well with small amounts of water.

Good pictures, Patience, and a nice job!

For housekkeping (dry bilge) I use a Par diaphragm pump and a timer. Timer is set for 2 minutes every 6 hours. With a small sump I would be able to make the remaining liquid surface even smaller.

Details of my timer setup, as requested:

12V timer from Amazon (various sellers seem to have the same timer) - see image attached.

The timer is tiny and I was concerned about the pump damaging its contacts so I used the timer to drive a relay. To further protect the timer contacts I put a resistor and capacitor in parallel with the relay (to stop sparking caused by the inductance of the coil of the relay). See schematic sketch attached.

Please excuse the untidy wiring - this was first a temporary installation for the winter.

Regards,
Nick

Solution and detail appreciated! Thanks Nick!

The PO had cut a hole in the bilge floor to access the water in the keel. He had the drip from the stuffing box drain into the keel and had installed a sump pump. This has worked quite well so I surmise he was ahead of his time.