Smelly subject

[snakebird]

Does anyone here have first-hand experience with a METAL holding tank?

I've tried the Nauta flexible tank; it smells awful after a season of hot weather. The poly tanks don't look like they'd stand up very long in a boat that's used 365 days/year.

Any suggestions? Other materials?

TIA

[delmarrey]

The chances are, it's not your tank. It usually turns out to be the hoses between the head and the tank. And it's the little sea creatures that cause most of the smell after a tank has been flushed out.

And if you did go metal, it would have to be 316 stainless steel. That's the only thing that would hold up to the acids. But I'd stick with the plastic.

Here's a site with lots of info!!!!!!!

http://boatbuilding.com/content/sanitation.html

[irwinsailor]

I changed all of the hoses to my tanks and I found a crack in the aft tank and repaired it. It helped but there was still odor. A friend told me about a Ozonater so I ran one for several weeks in different areas of the boat. The change was nothing short of amazing. I think the odors get into the wood etc. and need to be driven out and that is what a ozonator does.

[Curtis]

Hey Gunner,
I just googled "ozonator" and all I saw was hot tub/spa products. Do you have more info on your air freshening version?

Curtis
High Cotton

[irwinsailor]

I have a Alpine air. Mine works on 12 volt of 110 volt and it works like a charm. Bilge buster is made for boats. They are not cheep but they do work as well as they say.

[Alan Wheeler]

Well I have a little embarrasing story, I wasn't going to share but...
I have had an issue with our holding tank for sometime. I have tried all sorts of remedies, but to no avail. I don't know the construction internally and as this thing is like 1000ltrs, I wasn't going to lift the lid off it and take a look. When we sailed for the first time this year, the smeel that suddenly filled the downstairs area, when we healed over, was unbelievable. Yet I could find no leak.
To go back one further step in time. I had fitted a hose to the skin fitting where the outlet from the macerator pump exited the boat. This was to prevent the contents from running down the side of my boat when pumping out. when I did this, we had not had the boat sailing yet, so the hose would never touch the water, thus result in a possible syphone. I had also tested that possibility, and had found that the syphon wasn't possible as the pump seemed to "lock off" when it stopped. So the hose was forgotten about. Now back to the present.
I finally discovered, by a lot of Sherlock Homes'ing, (playing with the fresh water tank) that the tank is in two halves, with the two halves joined by a small hole at the bottem. A vent hose is on one halve only, thus, when the contents is above the hole, the one halve is effectively no longer vented and thus compressing the air in that tank, till it eventually finds a little hole to vent out. So I fitted a second vent and I thought problem was solved.
Well on entering the boat a few days later, I was greeted by the worset smeel we had ever had. Awwwe NUTS! was my reply. So up came the floor boards to check what was wrong. Well we had water, yeeep smelly water, seeping from the top of the tank. Huuuh!!! what the?!?!?! Yeeuup, you guessed it. And for those that didn't, the hose that I fitted to my skin fitting was now just ever so slightly below the water line outside. With the positive pressure no gone from the tank, the pump now allowed water to syphon back into the tank, which is below water line way down in the bilges. So the tank filled all the way to the top. Luckily all the Heads and basins etc are all way above water line when at rest, so only the tank was filled. But that is a common way of how boats sink at birth and how it was so easy to make a mistake to allow it. I should have neverput the hose on that skin fitting in the first place, but had tested the back flow and thought it safe. Obviuosely, the pressure in the tank was stopping the back flow and I had forgotten the hose.
Cnclusion, a week later, all smells are gone for the first time. I am a very happy wee sailor once again.

[delmarrey]

This is what Irwin has, but a commercial version. They manufacture ozone which is O'3 (three parts oxygen) It kills the micro-organisms that cause the orders. But they'll come back in time so it's best to get rid of what they are feeding on first.

It'll also kill your house plants........................_/)

[Alan Wheeler]

Ozone will kill anything. It is a really potent oxidiser and it attacks the lining of your lungs.
To get rid of the oder, there are several way's. Spray a week solution of chlorine around the bilge and on any surface that the leak has dribbled down. You can also use hydrogen peroxide in a watered down mix. I used chlorine and it work almost instantly and exceptionaly.
A product is available here, that is a bio thingy. It is supposed to be safe micro-organisms that eat the bad odor making orgonisms and give off lots of oxygen, which causes waste to break down faster and something else that kills the odor. I have used that also and it seems to work well. But at NZ$40 for 4ltrs, I wanted to find another way to solve my problem. err, which I did of course.

[irwinsailor]

WHAT!? Never have I heard anything like that about the use of a ozone generator for home use. Where can I find out if you are correct?

[irwinsailor]

Also we tried everything we could think of to get rid of the holding tank smell. I replaced and rebeded the lid on the forward tank. Replaced close to 50' of hose. Replaced the clamps etc. We washed the bilge with bleach. I hosed the bilge down with hundreds of gallons of water and the odor would return every time but there was improvment. I was getting close to selling the boat and buying a new one. Then I tried the ozone generator and it made a fantastic change. There is no doubt that I will need to run it from time to time from now on but it is a small price to pay.

[delmarrey]

The building maintenance industry will usually rent these out to local customers.

http://www.air-zone.com/indexovertur...OVMTC=standard

[Alan Wheeler]

I thought as soon as I pushed the submit button before, I should have added another line. One like this.
I would imagine that the amount of Ozone produced in a home type unit, would be so small, it would be of little consequence to us breathing the very small quantity in the air.

However, there is sufficient ozone produced from the old office photo-copiers that used to use the high voltage wires, to actually cause breathing problems with office workers, when exposed to long term and confined space working environments with the copier. Basicaly, Ozone does to living cells, plant and animal, what Oxygen does to steel.
What I am unsure about and would either love to hear from someone or I must look the answer up,.... will Ozone cause corrosion of metals faster than just the normal environment.

[GordMay]

I cannot recommend the use of Ozonators for the treatment of sewerage odours. Instead you must deal with the underlying cause(s) of the symptomatic odour.

Anyone with noxious boat odours, or any other plumbing problem, should read:
“MARINE SANITATION : Fact vs. Folklore” ~ By Peggy Hall
On-line at:
http://www.amazing.com/cruising/fvf.html
or
http://www.c34.org/faq-pages/headodor.pdf

Peggy Hall (‘The HeadMistress’) is President of The Hall Group Inc. (Peal Products), and the Author of “Get Rid of Boat Odors” (Seaworthy Publications 2003; 90 pages; $21.95), available at: http://shop.sailboatowners.com/detai...=400&group=327

Contact Peggy Hall at: peghall@peghall@sbcglobal.net

OZONE:

The ozone molecule is the triatomic form of oxygen, containing three atoms (O3).
Ozone generation is accomplished by passing a high-voltage alternating current (8-20kV) across a dielectric discharge gap, through which oxygen-enriched air is injected. As oxygen is exposed to the current, some molecules disassociate to mono-atomic oxygen and combine with diatomic oxygen molecules. Ozone is also produced naturally, in the stratosphere, by the action of UV radiation on Oxygen, and by the effects of sunlight on car exhaust fumes.

Ozone, like other photochemical oxidants, is sufficiently chemically active, that even at low ambient concentrations, unfavorable effects of exposure have been observed.

Ozone (O3) causes irritation to the respiratory tract and to eyes. Contact with high levels of ozone can lead to chest tightness, coughing and wheezing. When exposed to ozone, people that have respiratory or heart problems are at a higher risk. Ozone has been connected to increased hospital admissions and premature death. Ozone also has an impact on agriculture and crops.

Can Ozone Cause or Exacerbate Corrosion?

Yes ~ No ~and~ Maybe ...

Review of the literature indicates that ozone damages many different types of materials functionally and aesthetically. The damage is caused at the molecular level, by chain scissoring and cross-linking mechanisms. In some cases there is an added synergistic degradation of materials, due to the presence of other ambient pollutants, specifically sulphur dioxide and nitrogen oxides.

Elastomers:
The effects of ozone on natural rubber, general purpose diene rubber, and synthetic polymers of polyisoprene, polybutadiene, acrylonile-butadiene and styrene-butadiene, can be extremely damaging. Polymers such as polyethylene, polypropylene, nylon, and polystyrene appear to be embrittled by high ozone concentrations (ozone concentration>1000 ppm).
In contrast, neoprene, silicones, ethylene, butyl rubber, and propylene are inherently resistant to ozone damage.
Protection of elastomers can be increased by the use of antiozonants and waxes.

Textiles:
Cellulose fibers (such as cotton or silk) can be affected by ozone via the same mechanisms as elastomers (unsaturated double bond cleavage). Many textile dyes react with ozone, causing the colour of the dye to fade.

Surface Coatings (Paint):
Ozone has the ability to affect both the binder and the pigment in the paint, causing premature aging (ICP, 1996). The mechanism of deterioration is via the oxidation of the organic binder material similar to the mechanism of elastomeric degradation.

Ozone impacts on elastomers and textiles have been observed at levels as low as 0.020 ppm (20 ppb), while the lowest concentration at which impacts on textile dyes and surface coatings were observed was 0.050 ppm (50 ppb).

Metals:
In contrast to its effect on organic materials, ozone (on its own) has little ability to affect inorganic materials (e.g. metals and building materials). However, the presence of ozone in a sulphur dioxide-containing environment accelerates the corrosion of zinc, silver, aluminum, nickel, iron, and copper, among other metals. Ozone's effect on metals is also influenced by other environmental factors (e.g. temperature, humidity/wetness) in addition to the chemical composition of the atmosphere.
Ozone alone appears to have little effect on metal corrosion.

Cooling Water Treatment (Water Towers, Heat Exchangers):
Biological growth, scaling, and corrosion are the main maintenance concerns with cooling towers. Typical treatment has involved the application of chemicals such as chlorine, sulfuric acid, phosphorous, and zinc compounds (organics, biocide, pH stabilizers, etc). As traditional chemical water treatments are being restricted because of environmental concerns, ozone is gaining acceptance as a viable biocide alternative.

There have been several studies on corrosion rates in ozonated systems conducted and reported in trade journals and other literature. The initial premise for cooling tower systems using ozone for water treatment, was that because ozone is such a powerful oxidizer, those metals capable of developing a passive oxide film would be protected from the ozone residual have been mostly discounted.

OZONE:
~ may not be a significant health hazard,
~ may not present an increased corrosion problem,
~ is an effective anti-microbial, killing odour-causing bacteria.

BUT

Wouldn’t is be much more efficacious to prevent the underlying causes of these noxious odours (sewage), rather than merely treating the symptoms?

HTH,
Gord

[irwinsailor]

It looks like I have learned something new. The ozone generator that I have does not seem to be big enough to be much of a problem and I will continue to use it, but it is good to know that using a little more care may be in order. I am here to learn.

[irwinsailor]

I would like to add that rubber hoses can smell very bad. When I changed some of mine we were under sail. I rinsed them and placed them next to the cockpit untill we could dump them on shore. The smell was so bad that I tied a line to them and dragged them behind the boat. The smell was in the rubber. I now have pvc hose and it does make a difference, but the odor was still in the boat untill the ozone generator. I is true that a faint odor has returned but with more ozone I think it will be gone in a week or two.