water tank material ??

[MrBee]

Hello all,
We have not used the water tank since we bought the boat 3 years ago do to constant small particules in the water. When I finally cut an access / cleanout hole I found that the cover was made of plywood and just painted on the inside. Of course this is were the "wood" particules was coming from. The plywood was saturated and deteriorating. Last week I finaly pulled the top off. What I want to do is devide the tank into 2 parts, use one side as a fresh water tank for the head / toilet water supply and the other half as our drinking water supply. I know WHAT I want to do but am not sure what would be a good material to uae for the devider, it would be about 15" long by 17" high. I also need to make a new top for the tank that would be screwed down and have a cleanout port for each tank. The total capacity now is about 40 gallons and based on our normal use in a weeks time away from the dock we should be fine with about a 25 gal. / 15 gal. Split.

Thanks for your suggestions.
Brian

 

[Squidd]

1. What's the rest of the tank made of...?

2. Are you replacing the plywood top with ? (the same as divider)..?

3. What's the purpose of seperating the head (supply) water fom the drinking water if they are both fresh water...?

 

[MrBee]

The rest of the tank is glass I believe.

I dont really get #2, thats my question..

I don't want a water line that goes to the Head connected to the same tank that We drink from, Why take the chance of germs migrating back the line. Maybe theres nothing to worry about.

Thanks
Thought I was the only one up at this hour.

 

[Lee Coller]

What kind of heads to you have? Are they designed to be used off of the pressurized water supply? If so, I wouldn't worry about germs migrating back.

 

[MrBee]

No pressurized water on board. I will be taking the hose off the thru hull and clamping it onto the fresh water tank.

 

[Ross]

On a well waxed formica table lay-up a fiberglass panel large enough to cut both the top and the divider from. Bond the divider into place with glass and resin and gasket the top.

 

[Cool Beans]

Could you run to home depot and get a sheet of suitably thick plexiglass?

 

[RichH]

The rest of the tank is glass I believe.

I dont really get #2, thats my question..

I don't want a water line that goes to the Head connected to the same tank that We drink from, Why take the chance of germs migrating back the line. Maybe theres nothing to worry about.

Keeping the tank sections separated is a GOOD IDEA as 'retrograde' water system bacterial infection is a strong possibility from any *direct connection* of a water system to a 'toilet'. In your home toilet there is a large 'air gap' between the house water supply and the toilet tank for the exact same reason.
(Using waste water from a Tee set to a 'sink drain' is also a good way to retrograde contaminate the sink!!!! ... many of these intestinal entero-bacteria are rapidly becoming 'drug resistant' - "VRE", etc.)

As regards the fiberglass tank --- INCOMPATIBLE with potable/drinking water NSF/FDA standards !!!!!! Polyester fiberglass will contain lots of unbonded styrene monomer and other 'chemical fragments' that will continually (forever?) 'leach' into the drinking water; styrene monomer is a listed 'carcinogen'.
To remedy the tank internal surfaces consider to apply a 'low amine, low emissions' epoxy (roll-on) liner that is NSF/FDA approved for 'potable water'. Because of the small tank size the surface area of the tank internals will be 'borderline' for such chemical emissions / leachables .... but will be absolutely better than what you presently have so you will have to change out the water often. A good source for NSF/FDA potable water rated epoxies: http://www.nsp-specialty.com/pdf/120nsftds-07.pdf .... and then use a 'quality' carbon packed filter on the water distribution system to help 'strip' residual chemical 'fragments', change the filter 'often' / every 'few months'.
Ditto the new cover tank closure .... either a 'plastic' that is rated/certified for *potable* water or coated with a low amine 'certified' epoxy.
BTW - most 'bladders' are NOT rated / certified for *potable* water.

hope this helps.

 

[Scott T-Bird]

Find a new tank ...

I can't imagine why you would want to go thru the effort to modify an existing tank which is already significantly damaged. (Well, if removal and replacement is a real big problem, I guess I could imagine, then)

Yes, you definitely want to have separate chambers or separate tanks for the head supply. Cross-contamination is a real danger.

Find a suitable tank manufacturer and have them build it to your specifications ... simple, quick, safe, trouble-free, and more than likely cost effective (do you consider what your time costs when taking on complicated projects?)

 

[Stu Jackson]

No pressurized water on board. I will be taking the hose off the thru hull and clamping it onto the fresh water tank.

Why?

 

[MrBee]

Thanks for all the responses.

RichH. I misspoke on the material, the tank sides and bottom is more of a plastic and the tank itself is in very good condition. It's just an issue with the cover and my secondary decision to divide the tank . I thought there was an issue with using regular fiberglass, thats why I asked.

Scott T,
The tank is not damaged at all, didn't mean to convey that it was. It's only the top/cover.

Coolbeans,
I did look at Lowes and seen the plexi glass, it seemed to me it wasn't thick enough, especially for the cover. The cover is also the V birth base that the cushions lay on. Also whatever material is used as the divider I have to be able to glue / seal it in the vertical position so it will stay put if there is water on one side and not the other.

Stu,
The boat is a 1975 Irwin 10/4 that never had pressure water and the galley faucet was just a self priming hand pump that also will be replaced. There is no water heater or shower in the head. I'm just trying to keep it simple with a small electric pump.

Any recommendations on a small inexpensive pump ?

Thanks all.

 

[kloudie1]

Question is, why not use seawater to flush? Then before ya leave the boat after a weekend, put a half gallon of fresh through the toilet to help the lines live longer. Other option is Peggy's idea of hooking the toilet intake to the sink drain, below water level. Flush normally with seawater then before ya leave for a while, close the thru hull and put fresh water into the sink; then flush the toilet to empty the sink..

 

[Ken Cross]

If you do divide

The internal divider also needs to be pretty strong. Think one side empty and the other side 1/2 full and all that weight sloshing side to side. Hydraulic loads can be high.