Water tank smell and taste...No good

[Rick]

Great info! Thanks and keep that coming!

[capt lar]

a few ideas - maybe a long shot but....
check the source. are you filling off the same hose at the same location ? fill a bucket, cover it for a while and sniff to see if odor occurs. the problem might not be yours. offgassing in the tank could be release of something in supply. the testing idea at state lab is an excellent one.
silicon, if cured out, is probably not the cause, and if it hadn't cured out it probably would have failed by now.
fittings can be either metal or plastic. copper is used in houses, it was the lead in the solder that caused bigger problems. brass is as good as anything. many plastics are as bad - has to be rated for potable. i assume your distribution system is plastic with proper rating. odds are something else will kill you first.
i would not use tank water for drinking because of bacteria risk, more in the hoses than the tank. plastic really promotes growth. i assume you chlorinate or otherwise treat and then use filters to remove the chemical.
capt. lar

[Alan Wheeler]

It never ceases to amaze me the designs and builds of boats. I reckon every designer should be made to access every part of their design as soon as the boat is built. It might change a few thoughts when they once again approach the drawing board

Well Epoxy is actually a good alternative. Fully cured Epoxy is non-toxic and inert, so you shouldn't be able to tast it in the water. It also has the benifit of sticking to anything like the proverbial and could be brushed around the tank. Any excess will run down the tank wall and help as a build up on the bottom. Just insure you don't allow it to get to deep on the bottom, no more than say about 1/4" deep, or it will heat up and crack. You can apply two or three coats to the walls for thickness and compleate coverage if you like. That takes care of the sealant in the bottom of the tank as well.

[CSY Man]

Okay Gents, thanks for the latest round of ideas and suggestions, much appreciated.

Contact the health department..?
Hmm, that never occured to me, will consider it.

Also partial coating...Yup, why not.

The tank is being filled from the same source every time:

My garden hose.
I let the water run for 15 minuttes before I start filling up the tank so as to get read of the "hose taste".

(I live on a canal and keep the boat behind my house)


Keep the ideas coming, the more the better.

Thanks again.

[Richhh]

mmmmmm ..... is this garden hose a 'food grade' hose or just plain vanilla garden hose that continually degrades and leaches vinyl, etc. ?
:-)

[capt lar]

assuming the tank has been empty for a few days now, does the odor persist ? capt. lar

[GordMay]

Can you identify the odour/taste a little more precisely than ”...chemical kind of taste and smell...”?
(ie: Vinegar, hydrogen sulfide, ...)
Is the Float or Arm on your Wema instrument Aluminum?

Some Water Problem Links from the discussion at (“Sulphur Smell”):
http://www.sailboatowners.com/forums...05233064037.62

Water Quality Information Centre ~ from Ontario Hydro (Energy)
http://www.ontariohydroenergy.com/Wa...nformation.asp

Smelly Water ~ from Rheem/Ruud (HWT manufacturers)
http://www.rheem.com/includes/resour...ryPDF/1206.pdf

[Boracay]

Have you considered that your problem may belongs in the major overhaul category.
It sounds like the proper fix is to cut the top off the tank and to reline the tank with apropriate material. Multi axial fibreglass saturated with epoxy comes to mind, followed by a foodsafe coating.
A fix like this would also enhance the structural integrity of your yacht.
All the other fixes may be fiddling round the edges.

[CSY Man]

Yeah, there is a faint smell from the tank.

It is also empty in between sailing trips as I drain the tank into the bilge and it can sit empty for a month at the time.

Before filling it up for the next trip, I usually "rinse" with fresh water by leaving the drain open while I let the hose go full blast in the filler opening...(For lack of a better word)

Have also tried to keep it partially filled with some extra chlorine, then dump it before the next trip, then fill it with fresh water, etc.

The first day on the boat the water taste and smell normal, but that strange taste and smell usually comes back after a day or so, then stays for the reminder of the trip.
That rules out any contamination from the garden hose and filler neck.

As for describing the taset/smell...Hmm, slightly moldy with a twang of artificial smell...Not very strong and not very unpleasent, just a bit annoying.

The original factory coating in the tank is gel coat as per The Architectual Specificatons:

"The gelcoat shall be Glidden-Durkee polyester resins which meet the requirements of the US Food and Drug Administration and National Sanitation Foundations Standardsas not imparting non-palatable odors, tastes and colors.
The gel coat shall be sprayed evenly to a thickness of 18 to 22 mill."

(The above is for the whole boat, not just the water tank.)

Yes, I have thought of doing a complete surface job in the tank, but for now I am trying to do an easy way out...It may after all not be anything wrong with the surface.

In fact I have been sniffing every part that came of the tank to try to "identify" and pin-point the smell.

The last inspection plate that came off have a some white caulking around the gasekt for the tank level sensor, and that stuff smells just like the water, except much stronger.

I put in the sensor about 4 years ago, but have forgotten what I used for sealant.
So the plot thickens, I am somewhat thinking that the caulk may be the culprit as plenty of it was in touch with the water.

The old sensor was plastic, but I got a new one with a new gasket, and the new sending unit is SS.

Asked the manufactor if the rubber gasket was "food grade" and he was pretty sure it was as they ship em out in the thousands to sail and power boat manufactors all over the planet and have had no complaints...So there..

The next step is to look hard at the few caulk seams in the bottom of the tank and perhaps pour some epoxy resin over them to seal and secure.

Have also started looing into what materials is suitable for partial coating of the bottom and the sides..heard from one guy that it is really nasty stuff and that a respirator is need to apply it.

Will research more before I close up the tank.

Also looking to use rubber gaskets on the inspection plates to minimize contact with sealants, but need some food grade stuff to seal the thru hole in the bottom as the surface is way to un-even to trust an O-ring to seal it..

Thanks for the comments and the suggestions.

[capt lar]

seems most likely that the old caulking is breaking down (age or chlorine). the idea of removing as much as possible and sealing over the rest might be a reasonable lazy guy approach. unlike some others, i like silicon. we use it in lots of areas of food and water prep and consumption. i have never had a failure if it was kept dry and given time to cure. many builders now install undermount sinks to stone with silicon alone. as you mentioned, some of the other products mentioned are probably more of a health risk than what you have now. prep surface and clean up with denatured. (use fan to vent) i have used it as a bedding material in your uneven rubber gasket area with water tight results. o-rings combined with flat gasket can also help level out uneven surfaces in plumbing applications. in general, you know its cured when the silicon smell is gone - min 48 hr - 3 days is better. capt. lar

[Alan Wheeler]

18-22mill like that's mm like thats 3/4" to nearly an inch thick of gelcoat CSY. Yikes!
Trust me, the epoxy will be fine and it is fairly inert once cured.

[GordMay]

When seeking “Food Grade” products, remember:
Sealing (and other) materials that are food grade 'approved' are listed in categories including aqueous, acidic, dairy products, oil, beverages with less than 8% alcohol, and beverages with more than 8% alcohol. Some are approved for “direct contact”, and some are only approved for “incidental” contact.
Sorry I cannot offer more ...
Gord

[Catamount]

Alan Wheeler once whispered in the wind:
18-22mill like that's mm like thats 3/4" to nearly an inch thick of gelcoat CSY. Yikes!

In this context, one mil is equal to one one thousandths of an inch, or 0.0254 milimeters, so about 20 mils (18-22) would be about 1/2 millimeter.

Just for clarification...

[Boracay]

I cannot help but think that your problem is related to osmosis.
We know that water will slowly hydrolise polyester resin, sometimes forming fluid containg cavities.
The time span would be about right for this to be happening.
The hydrolised polyester could be trying to pull the fresh water from your tank, and the slight movement in the reverse direction could be giving you your taste.

[capt lar]

i would have suspected the glass was absorbing as well except csy guy said the tank was often low or empty, so i'm still thinking the old and unknown caulking. capt. lar