[ad_1]
Gasoline in tanks, whether for your yacht or tender, can explode. Ken Endean suggests an annual precaution
For many years we have been told that stored gasoline can “get stale” and that if engines are not used for long periods of time their tanks must be drained.
One problem affecting modern gasoline / ethanol blends is that the ethanol absorbs water from the air and ultimately the water / ethanol mixture undergoes phase separation.
Recently, the introduction of gasoline blends with higher concentrations of ethanol has prompted more warnings, including that gasoline should not be stored in a container for more than a month.
I may have inadvertently conducted a long-term science experiment because my boat’s main fuel tank has not been drained for 35 years and yet the engine is running fine.
My Saber 27 has a Yamaha 10HP 4-stroke outboard, which replaced a 12HP gasoline inboard when we bought the boat in 1986.
The fuel tanks are in the port cockpit locker and the engine runs on a normal 12 liter plastic outboard motor tank, with fuel reserve in a 50 liter stainless steel tank.
Separation in fuel visible; gasoline above, water / ethanol below. Credit: Ken Endean
The fuel is transferred between the tanks by a small hand pump.
At the end of each season, unused fuel is stored in the reserve tank.
Over time the contents of the reserve tank mix with new gasoline but some will be several years old and some must date from 1986.
In 2012, alarmed by reports of water in the fuel, I used the hand pump to suck the liquid from the bottom of the reserve tank, into a clear bottle, where it separated into two layers; I put the top layer of gasoline back in the tank and ended up with half a liter of what looked like water.
Since then, I repeated the exercise at the start of each season and this year the volume of water / ethanol had increased to almost a liter.
Continued below …
Duncan Kent examines the implications of switching from red diesel to white diesel and what you can do to avoid fuel…
Diesel bugs can clog filters, destroy engines, corrode fuel tanks and leave you helpless at sea. Ben Sutcliffe explains how …
Tim Bartlett explains how to diagnose some common marine diesel engine problems and fix most of them
Promotional function in association with GJW Direct. If your engine does not start, know how to find the source of …
Water in a tank can come from surface condensation, but once the water sinks to the bottom of the tank, it cannot easily re-evaporate.
If only half a liter of water / ethanol accumulated between 1986 and 2012, there is no reason why the rate of such surface condensation should have increased sharply.
Water is more likely to come from uptake by gasoline blended with ethanol, as ethanol-blended gasoline sales have increased over the past decade.
Ken Endean is an avid coastal pilot who has made an in-depth study of the coastal sea conditions around the British Isles
Despite reading authoritative reports on other types of deterioration in stored gasoline, I have yet to encounter any other issues that could be attributed to “stale” fuel.
That’s good, because draining the entire tank and getting rid of your gasoline is not an easy option.
The accumulation of water, however, could obviously cause serious problems in a few seasons if it is not removed.
I’m not a petroleum chemist and my fingers are crossed.
Although, for gas-powered boats, it seems that removing some liquid from the bottom of their tanks would be a wise annual ritual at the start of each boating season.
Expert advice on fuel maintenance
- Install a desiccant filter on your tank breather if possible
- Empty your tank at the end of the season, or at least empty the bottom part of your tank
- Disposing of old gasoline is not easy if it cannot be used. Some recycling centers and garages will accept it
- Check water separators and filters for signs of water
- Clean the carburetor if it has been left with fuel over the winter
[ad_2]
