Odor Coming from the Aft Berth Under Power

Jul 5, 2016
2
Hunter 35.5 Magothy River, MD
Hi all -

We just purchased a 1989 Hunter Legend 35.5. We spent months cleaning it out and deodorizing it while on the hard. However, during the first and subsequent outings, there is very odorous smell coming from the aft berth. Very disappointing after recovering all the cushions and getting out the old, musty boat smell...There is water coming in to cool the engine, but could that cause the smell that is obnoxious even in the cockpit? It doesn't smell like diesel, just really bad closed-up boat smell.

Thanks!
Tammy
 
Jul 4, 2015
436
Hunter 34 Menominee, MI; Sturgeon Bay WI
I had a similar problem with my 86 Hunter 34. No matter what we did there was a musty foul smell. Looked at my tanks, my head, hoses etc. and nothing seemed to work even scrubbing the bilge out and replacing the hoses.

What it turned out to be became evident when we started taking the woodwork apart and found that significant wood rot in areas we never suspected, for instance in the compression post and adjacent to the holding tank due to chronic water leaks over the years. In the rear berth we took the cover off the steering quadrant and found that water had been leaking down adjacent to the emergency tiller post because of a deck plate that hadn't been sealed when it was installed. Some of the wood had to be cut out and other parts of the wood which weren't critical structurally were given coatings of Smith's 2 part penetrating epoxy which worked wonderfully, better than other products I've used. Smell is now completely gone.

It was the wood all along and not the usual culprits.
 
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Sep 8, 2014
2,551
Catalina 22 Swing Keel San Diego
Is it only when you run the engine? The engine's air intake filter shouldn't cause a smell like that, but I suppose anything is possible. Also, as the engine warms up it probably heating up mold/mildew or standing water that in on or close enough to the motor to get warm and cause the odor to leech.
Similar to what Ilanortho said, you really have to 'get into the weeds' when searching for mold/mildew/wood rot that is source of musty smells. Hopefully you can locate the source with an interior clean out and only removing things that attached with screws. The problem with fiberglass boats that have a hull plus interior cabin liner construction method is that is mold gets into places between the hull & liner it is almost impossible to clean. One of the only reasons I was able to effectively spray a bleach solution in those kinds of places was because I had my hull fully inverted for a blister repair. On the inside I was able to reach places that no human being could normally reach.
In the off season, if you can, gut the hull as much as possible, including interior wood work. Make your best effort to take everything out that can be unscrewed and anything sensitive to moisture. Get a yard-work pressure sprayer from the garden section at home depot, the one that hand pumps and has a long wand, they are like $10 to $20. Spray a diluted bleach solution in every nook and cranny you can possibly get to, and when you think you are done search again for more places you can spray. Bleach kills mold spores. In the engine compartment/bilge; use plastic bags and tape to cover sensitive electronics like the alternator and air filter intake, then give the motor a good spray down with an engine degreaser/cleaner. Then clean the bilge under it. Constantly run a dehumidifier in the cabin during this process. You would be amazed at how much moisture you will pull from the inside of a boat and see how many times you fill the catch basin.
Its a pretty involved process to really ensure you kill a mold spores, but its worth it. After this process is done, you only really need to focus on keeping the interior dry.
 
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Jul 5, 2016
2
Hunter 35.5 Magothy River, MD
Thanks all! I'll let you know how it goes once we tackle what looks to be a bigger problem than I thought. :( And the boat was immaculate otherwise....
 
Dec 2, 1997
8,944
- - LIttle Rock
Once you find and remove the source, try Pure Ayre.
Good suggestion! I've been a huge fan of PureAyre PureAyre since I tripped over it at boat show in 2005. It's the only product I've ever found that will eliminate ANY odor, even diesel, and it's also safe for use around food...which means you can use it to get rid of the odor left by spoiled food in your fridge or ice box. However, it's NOT a cleaning product (and neither is bleach btw, although it does kill mold and mildew spores), it removes odors that remain AFTER the source has been removed. So you must find and eliminate the source of your odor 'cuz as long as the source of an odor remains, it will continue to generate new odor.
 
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Jan 12, 2011
930
Hunter 410 full time cruiser
I had a similar problem once. It was the o-ring on the seawater strainer that leaked just a little, so little that you didn't really notice it. But the water that was in the strainer would go foul, plus it leaked above some hose and when I loosen the clamps to get under them I found there was a nasty growth going on under them.
 
Dec 2, 1997
8,944
- - LIttle Rock
I have a 40.5 it had odors coming from many areas , I smell everything and do not like it! I installed a Marine Ventilation Systems the 12v one and ran vacuum line to my bilge and holding tank area and the engine room. It runs continuously using only .14 amps I now have no more odors and it also address mold and mildew in the cabin and bilge! marineventilationsystems.com
All you really have is an air freshening device. Remove the sources of the odors and the air won't need freshening. Granted, finding an eliminating all of 'em can be a major job but sometimes all it takes is a REAL bilge cleaning instead of just pouring more bilge cleaner into 'em and new sanitation hoses. And once you've done it, keeping the boat odor free without the need for any air fresheners is actually pretty easy. See the link in my signature....
 

JamesG161

SBO Weather and Forecasting Forum Jim & John
Feb 14, 2014
7,770
Hunter 430 Waveland, MS
significant wood rot in areas
We found ours from a plugged drain path to the main Bilge. (By the way.. the PO had the problem).
The wood rotting was the shim wood slivers used to level the Hold Tank by Hunter. If years of dust and crapola had not created a dam and a stanchion bolts leaking drip, there would have been a rot.
Stop the leak, kill/remove the rotting bacteria, and deodorize.
Jim...