That Old Boat Smell

Hey All,

I've talked briefly about this before... but after replacing all the floorboards down below (which were diesel soaked), scrubbing the entire inside of the boat with everything from vinegar to disinfectants, new heads, ALL new plumbing, our clothes and stuff have "boat smell" when we get home from a day on the boat. Don't smell a thing while there, no foul oders etc.. A buddy of mine who had a CHB for 16 years, said "yep". That's all he said. Granted we're talking 40 years old. Walk into a 40 year old house or church, first thing you smell sometimes is "old", depending on construction. Anyone else experience this?

Dave

Hi, a friend of mine who had worked on various trawlers and supply vessels came to have a look at my recently acquired boat last spring. I told him that the front cabin smells of mold and rot, but after a quick tour he said: 'No, this is just boat-smell'

Get the bilge clean. And, good luck with that; lots of bilge is beyond normal reach in most boats. Almost nothing better than taking the boat out on rougher water and bouncing it around with clean soapy water in the bilge.
Lots of ventilation.
Keep the bilge as dry as practicable. Many boats simply do not drain to the bilge sump. Add pumps as necessary.
Make sure that nothing awful is going on with the black water components: hoses, vents, tank, fittings.
Make sure the topsides are not leaking. Or plumbing.

We've now had three largish boats. They all smelled when new to us and we got them all under control and were able to keep them that way. Residual fetor on bedding and clothing was much reduced after much effort.

Happily, human noses quickly quit reacting to background smells.

I have an old wood boat. The way to beat the boat smell is to vent the bilges. I use plastic pipe and a bilge blower with and electronic controller to slow the motors down. A rheostat also works to slow dc motors. I have 5 wt bulkheads and 6 bilge areas. Some share a vent. By running the bilge blowers slowly the air is changed and replaced with cabin air. Cabin air is replaced with outside air. It also keeps the bilge dry. Clothes, cushions, curtains and other air absorbing items will have to be washed or replaced, but the boat smell will be gone. Also keeping an open bar of some smelly soap in clothing drawers or closets will help.
Fix any diesel leaks, clean up any spills and wash the engines. Diesel only smells if it's present.
I live aboard and don't find venting the bilges costly in the winter.

In her book on getting rid of boat orders Peggy Hall recommends PureAyre.
http://www/pureayre.com It’s found in pet stores. Tried it, it worked well for us.
You do have to address the source of the odors first though.

Ha, I wish all I was fighting was generic boat smell. Generic boat smell is perfume compared to whatever crawled up the water line and died in the water heater. Cold water taps are fine, but turn on the hot water valves on the galley or head faucets and yeow, it'll knock you over. Has an evil smell like sulfur and warthog flatulence and gas from the deepest volcano. I think it's a nasty corroded anode in the water heater but that's just a guess, can't think of anything else. The six-gallon water heater is original to the boat (1996). Tried flushing, tried bleach in the tanks, ran the hot water heater itself, flushed it with the super-hot water from the engine when we're underway, left the hot water heater off -- makes no difference. We're replacing the water heater in the spring when we launch.

I second the ventilation, my boat was built in the 50’s, I don’t have “old” Boat smell. I have a more open type of bilge though, any ventilation will help

Sometimes the smell is the adhesives in the plywood used in the interior gassing off. I have heard of those who have had good results sealing the backsides of all cabinet doors and any hidden surface that does not already have paint or varnish. This is also an issue is many RVs for the same reason and might be a health issue. Google Lumber Liqudators and formaldehyde for a worst case scenario!

Ventalation is good. We on the boat 24/7s so the big smells are pretty much what we cooked last night.

If you have salt water head and leave the boat, dump a gallon of fresh water in the head before you leave and flush, maybe add another. I think a lot of boat smell is stale salt water and the critters that live in it gone bad.

Woodland Hills said:

Sometimes the smell is the adhesives in the plywood used in the interior gassing off. I have heard of those who have had good results sealing the backsides of all cabinet doors and any hidden surface that does not already have paint or varnish. This is also an issue is many RVs for the same reason and might be a health issue. Google Lumber Liqudators and formaldehyde for a worst case scenario!

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There is an owner of a boat just like ours in Anacortes Washington, and he told me while they were sanding the insides and painting, they became very ill. Might be something to your words. Thanks.

In my experiences there are only 3 boat oders, fuel, poop, and mold. First you have to stop the supply, then you have to clean, then you vent. Venting usually means fans moving air into the hidden spaces with open doors, hatches, and windows.

Doug said:

In her book on getting rid of boat orders Peggy Hall recommends PureAyre.
http://www/pureayre.com It’s found in pet stores. Tried it, it worked well for us.
You do have to address the source of the orders first though.

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Can even use in bulk with a fogger

Consider trying an ozone generator. Run too long I believe it has deleterious affect on plastics etc. Simple to use,worked for us, though that was at home.

The "old boat smell" is usually a chunk of wood someplace that is rotten.

Usually impossible to locate as occasional wetting , like fridge condensation will continue to feed the rot.

I agree with vent the bilge. We were able to get rid of the smell by making sure the new air was coming into the salon and old air was exiting from the engine room. We covered all engine room vents except one, where we installed a continuous-running exhaust fan blowing out. This means the air going into the engine room must come from the cabin. Look around and figure out where all holes between the cabin and engine room are - make sure there are holes between your smelliest rooms and the engine room (we have ours from one of the heads and the v-berth). We then put a vent in the flybridge over the helm in the salon for air intake. This way fresh air flows through the salon, down into the cabins, through the heads, into the engine room, and out of the boat. Obviously when we cruise we remove the engine room vent covers and kill the fan.

kthoennes said:

Ha, I wish all I was fighting was generic boat smell. Generic boat smell is perfume compared to whatever crawled up the water line and died in the water heater. Cold water taps are fine, but turn on the hot water valves on the galley or head faucets and yeow, it'll knock you over. Has an evil smell like sulfur and warthog flatulence and gas from the deepest volcano. I think it's a nasty corroded anode in the water heater but that's just a guess, can't think of anything else. The six-gallon water heater is original to the boat (1996). Tried flushing, tried bleach in the tanks, ran the hot water heater itself, flushed it with the super-hot water from the engine when we're underway, left the hot water heater off -- makes no difference. We're replacing the water heater in the spring when we launch.

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I had the same issue on my boat. It wasn’t my water heater, because it wasn’t plumbed in. All the research I did led me to the conclusion that the tank was fine, and that my water lines were fouled. I was going to replace them with pex, but ended up selling the boat first.

Wayfarer said:

I had the same issue on my boat. It wasn’t my water heater, because it wasn’t plumbed in. All the research I did led me to the conclusion that the tank was fine, and that my water lines were fouled. I was going to replace them with pex, but ended up selling the boat first.

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Thanks for that reply. I assume my tanks are fine too because running the cold side smells just fine (downright pleasant actually). It's a very odd problem. The water also foams on the hot side, fine bubbles, which never seems to go away no matter how long we flush water through that side. I hope it's just the water heater though. Replacing all the hot water supply lines to the galley, two heads, and the bar sink on the aft deck would be a major pain.

K,

We once had a foaming problem at home. Turned out the indirect water heater was leaking antifreeze from the heating system into the domestic water. Discovered it quickly but was scary. Maybe have the water tested for an antifreeze leak.

Rob

Datenight said:

K,

We once had a foaming problem at home. Turned out the indirect water heater was leaking antifreeze from the heating system into the domestic water. Discovered it quickly but was scary. Maybe have the water tested for an antifreeze leak.

Rob

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Thanks very, very much. Hadn't even considered that possibility but now that you mention it, the previous owner did mention there is a very slow leak in the starboard engine antifreeze. He was never able to find it and the loss is tiny, maybe one pint per season/year (the port engine never loses any) but maybe that's enough to make the water foam when it comes out of the tap. Luckily we never use the tank water for drinking, just washing. I still don't have a clear image in my head of how the running engines heat the house water, how that exchange is plumbed, but it sounds like it's time to learn. Thanks again.

kthoennes said:

Ha, I wish all I was fighting was generic boat smell. Generic boat smell is perfume compared to whatever crawled up the water line and died in the water heater. Cold water taps are fine, but turn on the hot water valves on the galley or head faucets and yeow, it'll knock you over. Has an evil smell like sulfur and warthog flatulence and gas from the deepest volcano. I think it's a nasty corroded anode in the water heater but that's just a guess, can't think of anything else. The six-gallon water heater is original to the boat (1996). Tried flushing, tried bleach in the tanks, ran the hot water heater itself, flushed it with the super-hot water from the engine when we're underway, left the hot water heater off -- makes no difference. We're replacing the water heater in the spring when we launch.

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Try taking the anode out altogether. If the water has h2so4 it will release hydrogen sulfide ( rotten eggs). Worth a try

dennisspain said:

Try taking the anode out altogether. If the water has h2so4 it will release hydrogen sulfide ( rotten eggs). Worth a try

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Dennisspain is on the right track. Check out this link

Solving rotten-egg odor in water heaters with aluminum/zinc, powered anodes

BruceK said:

Consider trying an ozone generator. Run too long I believe it has deleterious affect on plastics etc. Simple to use,worked for us, though that was at home.

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I have used one after all the stink issues were addressed in the boat. They work fantastic in reducing residual orders. Used a couple of times a year will keep the odors under control. They also help to get rid of residual diesel smells. This is the one I have, but there are many that will do the same thing:

https://www.amazon.com/Mammoth-Comm...coding=UTF8&psc=1&refRID=NPMDJ8JD0DRJ9BE18HKV

The other suggestion is a good dehumidifier running full time while you are away. It will need to drain down a sink so it won't shut off once the tank if full. The lower humidity will help you lower the mold/mildew issues that can cause odors. The damn stuff grows behind cabinets and along the hull sides if the humidity is too high. DampRid might look like it is working, but when you are taking 2 gallons of water out of the air in your boat daily with a dehumidifier, you will see the difference in the smell pretty quickly in the PNW.

By the way, do you have a hollow keel or part of one? If so, you may have something growing there that will keep stinking until you find the hole in your bilge that is allowing water to get into it and letting stink back out. I had this issue from open screw holes under a bilge pump that was removed by a previous owner. I opened it up and cleaned the 6" hollow space under the bilge floor and above the solid part of the keel. Then resealed up the holes. That alone fixed 90+ percent of the odor causing smell in my last boat.

Good luck!

Well, as to diesel, I love the smell. Now sewage is another matter.

jimisbell said:

Well, as to diesel, I love the smell. Now sewage is another matter.

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I love the smell of diesel and grease in the early morning, that's always something that reminds me that I am in the best place I can be

L

Lou_tribal said:

I love the smell of diesel and grease in the early morning, that's always something that reminds me that I am in the best place I can be

L

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Growing up I spent some of my teenage years as a deckhand on a party boat and that was some of the best years of my life. The smell of diesel and a cup of coffee at 4AM as we headed out to the Kelp beds was a breath of heaven.

Ha, I wish all I was fighting was generic boat smell. Generic boat smell is perfume compared to whatever crawled up the water line and died in the water heater....We're replacing the water heater in the spring when we launch.

That may or may not be necessary...what's make/age of your water heater?

HeadMistress said:

Ha, I wish all I was fighting was generic boat smell. Generic boat smell is perfume compared to whatever crawled up the water line and died in the water heater....We're replacing the water heater in the spring when we launch.

That may or may not be necessary...what's make/age of your water heater?

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Thanks Peggie. Sorry for the delay, I had to break out the manuals since the boat is an hour away like a popsicle on jackstands at the moment. It's an Attwood EHM6 (six gallon). The boat is a 1996, but that heater may not be original. I have a copy of the previous owner's 2004 survey and it was there then, so that would make it at least 14 years old. According to Attwood's website they say they started producing marine hot water heaters "20 years ago" so that would be about right. I found the manual (pretty short, really just an info sheet) and it does talk about a flushing routine for bad smell. The city water at the marina is pretty good as far as I can tell, zero odor or taste or sulfur, so I'm not sure Attwood's directions apply here. I might give the flush routine a try before we replace the whole thing. I don't see anything about a sacrificial anode though.

http://www.atwoodmobile.com/manuals/waterheaters/MPD 93757 PS 11.19.07.pdf

ALL water, city or marina has thingies growing in it. Some survive the chlorine, Non use for a while makes it go sour. If I dont put chlorine in tanks and flush through the pipes every so often I will get tat smell. If you dont use the heater for a while I could see how all the water i it could go sour.

I don't see anything about a sacrificial anode though.

According to Attwood's website, their EHM6 water heater has an aluminum alloy tank...they don't mention whether the aluminum is anodized or not. No mention of an anode either, so I doubt if it has one.

Their owners manual includes the following:

FLUSHING TO REMOVE UNPLEASANT ODOR
rotten egg odor (hydrogen sulfied) may be produced when the electrogalvanic action of the cladding material releases hydrogen from the water if sulfur is present in the water supply the two will combine and produce
an unpleasant smell.

1. Turn off main water supply. Drain the water heater tank and reinstall
drain plug. Remove the pressure-temperature relief valve. Mix
solution of 4 parts white vinegar to two parts water. With a funnel,
carefully pour solution into tank.
2. Cycle water heater with the above solution, letting it run under normal
operation 4-5 times.
3. Remove the drain plug and thoroughly drain all water from the tank.
Flush the water heater to remove any sediment. You may flush the
tank with air pressure or fresh water. pressure may be applied
through either the inlet or outlet valves on the rear of the tank or
through the pressure-temperature relief valve coupling located on the
front of the unit.

Highly unlikely that sulfur is present in any municipal water supply, but what the heck...draining and flushing it is worth a try before you spend the money for a new water heater. I wouldn't add chlorine though...it's HIGHLY corrosive and can actually exacerbate the problem.

HeadMistress said:

Highly unlikely that sulfur is present in any municipal water supply, but what the heck...draining and flushing it is worth a try before you spend the money for a new water heater. I wouldn't add chlorine though...it's HIGHLY corrosive and can actually exacerbate the problem.

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There isnt any sulfur in the water. Its the things that live in the water and DIE that produce sulfur dioxide. Even city water treated properly has things that are harmless living in it. Normally the turnover is rapid enough that they dont die but in an unused boat they die and decay.