Converting Fuel Tank to Water Tank?

[Roniszoro]

I am interesting in purchasing a sloop where one the of the water tanks has been converted to a second diesel tank. It now, for me, has much to large a fuel capacity and too small a water capacity. (I am not interested in adding a water maker, as my future sailing plans will not include sailing over the horizon for months or years at a time.) So I'd like to convert that tank, which was formally a water tank, back to being a water tank. I don't believe that the plumbing part will be particularly difficult, but how do I get the water that will be in that tank to be potable? Is that possible? If I re-convert the tank back to water, do I need to give up on the idea of using it for potable water and therefore get water from another source for cooking and drinking?


Thank you in advance for you input.

[thinwater]

I suspect the reason you are not getting responses is that while theoretically possible, it is practicably impossible. It's hard enough cleaning a diesel tank to put diesel back in it. When you consider that you will needed to get down to a few micrograms of contaminant, including any absorbed into the tank, it's going to be a horrible undertaking. Clean, then clean again, then clean again, then steam, and steam, and steam some more. Even then, you may need a carbon filter system.


Depending on baffles, it might not be possible.

[slowneasy]

Can you remove the tank and replace with a new water tank? If not I would look at other options and enjoy the extra fuel.

[Cheechako]

NOPE. Cut the top off and install a plastic tank inside might work though.

[Patrigo]

Ease of contents change depends on the tank's construction materiel. Years ago I cut the end out of a diesel tank and steam cleaned the whole thing. Welded the end back on and it was like a new water tank.
Patrigo.

[hpeer]

I have a steel boat with water tanks integral to the keel. I painted the tanks with some 2 part epoxy but then top coated that with 3 coats of potable water 2 part epoxy.

Not sure that would work for you but might. I would try calling Ameron/PPG and getting an opinion.

[meirriba]

In my expirience it is a one way process.
You may go fro water to diesel but not from diesel to water.
The cost of cleaning and getting rid of the smell will be higher than a cost of replacement.

[Capn Jimbo]

Think about it... would you seriously consider converting an old and rusty gas can to store drinking water on your next camping trip? Under any circumstances? The only suggestions that would seem to have validity would be to use the old tank as a frame or container, but even then a flexible tank might still absorb fuel.



Replace it.

[GaryBode]

So instead of buying a cheap plastic tank for potable water you would rather use a tank that was used to store diesel fuel? Think about that.

[carlheintz]

Oye! NO! Can't, shouldn't, wouldn't ever do that!! The diesel permeates the plastic, you'll NEVER get it clean. Buy a new tank, toss the old one. I know, wasteful, expensive, etc., but far cheaper than the alternative when you put fresh water in a diesel permeated tank, drink the stuff (if you can) and smell diesel every time you turn on the tap. Imagine the strange aroma you'll have onboard first time you take a shower. Eeek!

[boatman1]

During the second world war the marine landing force on Peleliu were supplied with drinking water in drums that had previously been used for fuel storage. The deleterious effects on the poor jarheads was almost as serious as what the Japanese defenders were doing their best to accomplish.

[waterman46]

Converting fuel tank to water is senseless (and probably undoable). You can make water but you absolutely never will be able to make your own fuel. I converted water to fuel tank so I could motor Cabo to Ensenada without refill if I had to. You can make thousands of gallons of water for the contents of just one fuel tank.

[Mike Banks]

I once converted a metal stainless steel diesel tank to water. It was done by a thorough steam-cleaning of the tank using pretty strong detergent and steam, then several flushings with fresh water. When the water no longer frothed when a sample was put into a bottle and shaken, it was good to go.

Unless you hot clean it with steam--that diesel smell and taste will haunt you for a very long time.

[ohgary]

NO.. Plain and simple no... Reuse the space sure. reuse the tank NO

[Dooglas]

You never told us what the tank is made from - galvanized iron, steel, molded plastic, stainless steel, fiberglass, monel, etc. Some materials are harder to clean than others. Some are impossible.