Converting Water to Fuel

[Don1500]

Got ya. No this is not about the engine that uses water for fuel.

I am currently looking at a boat that has two water tanks, 50 and 30 gal. And one Fuel tank 30 gal. I was thinking that since it also has a water maker capable of 1.5 gph maybe 80 gal of water stowage may be a bit of over kill. (solo sailor don't need much) Should/could I convert the 30 gal water tank to fuel? The existing fuel tank and water tanks are plastic of some kind, don't know if they are the same type. Are there a different types of plastic used for fuel and water? I don't want to rip the boat apart to do this.

[David M]

Polyethylene is a common material for fuel tanks. You would want to make certain the type of plastic, fittings, fuel lines and fuel vents are suitable for holding and transferring fuel. If you are not certain of the material then I would not take that chance.

[Don1500]

Originally Posted by David M

Polyethylene is a common material for fuel tanks. You would want to make certain the type of plastic, fittings, fuel lines and fuel vents are suitable for holding and transferring fuel. If you are not certain of the material then I would not take that chance.

I haven't checked that closely yet, not my boat yet. If I buy it I will check further. I was just wondering if it would be better to have more fuel and less water stowage. BTW I do not foresee an ocean crossing, but you never know.

[vintageray]

Okay, trivia question. What was the powder that the crew of Kon Tiki added to sea water to get hydrogen. (I don't remember, but they did it.)

[zeehag]

with a watermaker and a 30 gal tank as well as a 50, i would use the 30 for extra fuel--make sure you change out the fittings and hoses to make them able to be safe and functional with the fuel.

[captain465]

Just make sure that you understand the limitations of a watermaker. You would not want to make water in most harbors due to the proliferation of pollutants there.(Hydrocarbons kill RO systems)

[brutb]

I would go for more water storage, you have sails for power. You can use your engine for harbor and for charging batteries if you do not have solar. You can wait for wind but it is hard to make water if the water maker goes TUP.

[Pete7]

Don, I suppose it depends on were you fancy going? Our own Mark J recently crossed from the Canaries to the Carib using 100 litres of water over a few weeks. Okay he is from Oz so this figure will have been supplemented with cold beer, but shows that a solo sailor doesn't need much. So you could convert the 50 gallon water to fuel. After all running the engine on the fuel creates the elec to run the watermaker to make water.

However, converting those tanks is a one way ticket. Putting diesel into a clean dry water tank is one thing but trying to go from diesel to water will be painful.

If your not planning on crossing oceans then perhaps a 50/50 water fuel split as suggested by Zee would be the better option.

Pete

[roverhi]

What's the fuel consumption of the engine?? If it's the typical 20-30hp diesel on a moderate displacement boat, you'll get close to 60 hours of powering out of 30 gallons. That has been more than adequate range for us in sailing around SoPac, the West, East Coasts and assume the Carribean especially if you carry a few Gerry cans of extra diesel. We found diesel available anywhere there are people. That has not been the case with water, however. There are some passages that might require more fuel if you are one of those types who turn on the engine when boat speed drops below 4kn.

For a solo sailor, 50 gallons of water would be adequate though not excessive. The water maker can make up for any lack of storage but. It's a mechanical device that requires energy to work. I'm an retro grouch when it comes to depending on anything but nature for things that keep me alive. What are you going to do if your electric generating capacity goes away??

I can see switching the 30 gallon tank to fuel but I wouldn't do it.

[Vyndance]

You have plenty of opinions above on weather or not to convert. If you do, add a 10 gallon water tank. Do not run the water maker into your only water supply.

[hellosailor]

Don, bear in mind that fuel, even diesel, goes stale if not used or pickled. So will you really be using the 30-gallons of diesel(?) in a reasonable time, say, two or three months? Routinely?

If not, it might be better to stow some jerry cans, and only fill them with extra fuel before a major trip, so the fuel is kept fresh and sealed up.

IIRC a number of the major ocean races typically only require a 36-48 hour fuel supply and depending on how much boat you are looking at, 30 gallons could easily be 48-hour supply. OK, not enough to cross the doldrums, but enough for most sailors on most shorter runs.

[Don1500]

Great answers, now I need to decide which way I want to go. If I get that boat.

[Tashtego]

Do not convert your water tank to a fuel tank. Most water tanks are ordinary polyethylene but fuel tanks are made of cross linked polyethylene. Water tanks will be rapidly degraded by fuel.