Odor elimination on a 1984 NEWPORT N27

[rmwac]

Hi All: This is my first post. I'm the new owner of a 1984 Newport N27 which is beautiful except for a persistent combination of petroleum/chemical cleaner odor strongest beneath the companionway. As the boat is opened and aired out it dissipates, and I never thought it would be a problem......nothing that a little cleanup and airing out couldn't fix...... until the folks in the next door slip told me that the old owner became too discouraged with the smell and finally dumped the boat. Now I'm very worried...
Let me tell you what I've done to this point in a general cleanup of the boat, determined to cover all bases.... Beginning forward, I removed all old sanitation tubing, including about 7 feet of overboard discharge tubing, diverter valve, and hand pump. NASTY. I removed and completely cleaned the holding tank. I also steam cleaned the holding tank compartment. I replaced all tubing with the fancy $$ "odor-safe" tubing. A minor odor problem reasonably quickly solved.
On to the bilge. Each storage hold inside the cabin has a "downstream" drainage route to the bilge. With a power washer dispensing a diluted Purple Power/clorox/Dawn detergent mixture, I sprayed all of these inaccessible "tunnel" passages alternating with a brushing out with a long handled Christmas tree brush used for drier vents. The filth was amazing!! The bilge itself was cleaned the same way, and I got rid of 'tons' of algae slime and oily residue. I then meticulously cleaned the diesel engine, as well as every square inch of exposed anything in the engine compartment. It looks darn near new. The Purple Power mixture worked very well indeed.
Closing the boat up for the day with a big sense of satisfaction...... returning the next morning..... not the least bit of reduction in the petro chemical odor! Just as intense as ever. SO..... I must need better ventilation. I saw a website hawking a boat/RV ventilation system called CLEAR-AIR. "Guaranteed" to eliminate odors anywhere in the boat by snaking various sized ventilation suction lines to problem areas on the boat, and then collecting them in a 125 cfm central fan unit, finally exhausting outside of the cockpit thru a vent. $695...WAY too pricey for something I could easily build myself. $100 later, I had reverse-engineered this system using a FAN TECH centrifugal fan from EBay and some PVC parts and spa hose from Lowes, I installed it, and ran a 2" ventilation suction line into the engine compartment fuel tank area, another 2" suction line to the aft cabin itself, and a third 1" suction line to ventilate the bilge. The unit runs continuously off shore power ; the cabin air is somewhat better, but the exhaust in the cockpit stinks of this familiar petro/chemical stink to high heaven. There is big time active outgassing somewhere. I'm now convinced that the odor is originating in the area of the fuel tank, but this area is inaccessible; covered up by a plywood
"floor" for an optional unused quarter berth. This plywood is not structural. There may have been a spill of some solvent, cleaning product, motor oil, fuel... years ago; there may be a chronic leak in the fuel or breather hoses, a loose clamp, decomposing fuel sender gasket, who knows? I can't get to it. I'm currently leaning toward removing the quarter berth plywood floor to gain access to the fuel tank area to check it out. I'm even willing to remove/discard the old tank and hoses and relocate a new one to a more serviceable area if it'll end the problem. Any help from your experiences would be really appreciated. I was convinced that all stink has to be finite, but I'm beginning to think the boat is haunted by a stink with a life of it's own, that we may never eliminate.
My wife and I are really frustrated, and I can't imagine we'll ever spend a night aboard her until we get to the bottom of this. It's driving us nuts. If you have read along this far, thanks so much for hanging in with me , RON W Watkins Glen, NY

[Faster]

It does sound (smell?) like a fuel tank leak - you've "gotten" everything else... wondering why there's no evidence of it in the bilges, though.

However what you describe as a petrochemical odour doesn't sound like a diesel leak... which has its own quite distinctive smell. I could see a gasoline leak creating such strong obnoxious fumes but you mention a diesel engine.

I guess it's time to dig into the tank location and see what's what.

[mike dryver]

you don't really have choice other removing quarter berth and possibly sole over tank. air out the boat really well, at least whole day then put your noise to work or better still ask someone who as not been on to come on board and start at companion way using their sniffer to track down area where odor is most intense.

[waterdog52]

Is there any "plastic" products, foam insulation, or particleboard /wafrboard /manmade wood used to construct an aftermarket project such as refrigeration or climate control? Had some applaince experience in which the plastics took over a year to cure. That odor was chemical.

[olson34]

If this a Newport 27S model, there are only so many places for an odor to hide.
These were not a large or very complicated boat.
From the narrative, you have already done 90% of the work to clean up the interior. This was work that the prior owner was unwilling to do or have done, and is an unfortunate part of older-boat ownership.
I would not look for a "snake oil" product to somehow magically banish the odor... nothing will ever succeed like eliminating the odor at the source.

You have described a boat that has had continual water leaking in and growing "stuff" everywhere.
I betcha that there are still areas that need to be opened up and cleaned up.

This being a Newport, one thing to double check is the hull to deck joint. I used to know a Capital Yachts dealer and was told that many models had a poor sealing job done on that joint. Result is seeping of rain water and water ingress from spray.

Beyond that, most all production boats lack enough (any?) ventilators on the face of any and all interior sealed compartments to allow free air flow. I have added about ten vents to our interior over the years. We bought an acknowledged "fixer upper" with a lot of mold and mildew from sitting closed up for several years. It took us quite a while to clean up everywhere so that when we opened the hatch there was no longer any odor at all. Nowadays friends comment on how our boat is one of the few with no "boat odor" when they visit.

If you have areas like an aft berth with no access, don't be afraid to simply create a 9" hole in a surface and then install a deck plate to cover it after you clean up the enclosed area. Everywhere that the builders left sanding or fiberglass dust, count on this attracting moisture and then mold and mildew.

You are on the right track. Don't give up!

[Donaldpeter]

Hello, I own a Newport 28 and went through something similar. When I bought the boat it had holding tank and fuel smells. My wife could stand it. The previous owner used bilge line instead of sanitation from the holding tank to the hull fitting on the boat and the bilge line was leaking into bilge. I replaced this line. I needed a heat gun to soften the lines to make some of the connections and I used double clamps.

I cleaned around the engine and found no fuel leaks around the engine. On the 28 the plywood is loose in the quarter berth and easily removed exposing the fuel tank with fuel inlet, fuel vent, fuel sending unit, and two lines to the fuel filters and engine. The fuel sending unit on my boat was leaking. Tightening the screws 1/4 turn fixed the issue. I may use sealant around the screw threads once the fuel level drops to keep the fuel coming up the screw threads. Have fun.

[rdstanley]

You may want to check your batteries. A friend of mine had an odor problem that was finally traced to old batteries.

[rmwac]

Hi All: Thanks for the ideas. There are four fiberglass cabin compartments that have no access to the outer hull. So there is "dead space" between inner and outer fiberglass. I'd like to get appropriate sized deck plates and get to each area for a good power washing and airing out. I have also been able to examine the fuel tank connections through the provided tiny inspection cutouts. So far, they appear dry and free of leaks, but I can't get too good of a look yet. I will install a deck plate through the quarter berth plywood to inspect and clean the fuel tank better. I will also have to try to paint the holding tank compartment, as it still has minor odor, despite changing all the single-walled (original? sanitation hoses and installing odor-safe hose throughout. I also eliminated the overboard dump pump, diverter valve, and 6 feet of tubing... What a bear it was to get the stiff new hose connected and double clamped up to the deck pumpout fitting!!! My arm was buried to the elbow thru the miserable little 6" x 6" access door. Heat gun and a rub of dawn detergent on the fitting got it done... Even though I thoroughly scrubbed the holding tank compartment to death with Purple power/clorox/dawn mixture, there must still be matter absorbed into the glass. Maybe Bilgekote or another marine paint will render the area finally sealed and odor-free??

[QuickMick]

after a good scrubbing of the storage spaces under the settee i hit them with this and it did a find job:

[mitchbrown]

I think that the foam in cushions begins to break down after many years of exposure to air and other polutants that you are talking about. Before spending money and time cutting the boat apart you could try removing all the cushions from the boat and let it air out, wipe the surfaces down where they were and then see if the smell is reduced or gone. worth a try anyway.

Mitch