Should the fuel tank be full for long term storage?

[nknowland]

we are hauling our boat in FL for storage on the hard for 4-5 months. Our diesel tank is half-full and we don't have an easy way to fill the tank before haul out.

Will this be a problem? Or should be jerry jug fuel from shore and try to leave the tank full. Is moisture/condensation in the tank a concern?

thanks!

[Vasco]

Most cruisers store with full tanks. I always do this and the guy who does fuel polishing in Ft. Lauderdale recommends full tanks. Make sure you treat the fuel. Jerry jugs is what I do. Where are you hauling?

[S/V Alchemy]

Full tank are a good idea because they reduce the area of fuel exposed to air. If you have a full tank with the fuel going a little way up the vent, you get a mere square inch or so (pi x vent hose I.D. radius) of fuel exposed to the air. Of course, getting this right is tricky, and you may learn your vent hose is not secured at the tank top properly, but such is the learning curve.

If you leave a tank even 7/8ths full, you have the whole "surface of the pool" exposed to air and moisture transfer from the vent. This is an invitation to getting condensed water in the fuel, particularly if that tank is nice and cool on the shady side of the boat, and the surrounding air is warm and moist.

You might wish to shut the vent entirely as an option, but I'm not keen on that idea, either.

I have full diesel tanks on my parking-lot placed steel boat currently. The diesel is there primarily to keep the tank interiors non-rusted. I will polish it when I get the new engine installed and the fuel polishing system working, but I don't expect it to be still viable after two years. We'll see.

[nknowland]

Originally Posted by Vasco

Most cruisers store with full tanks. I always do this and the guy who does fuel polishing in Ft. Lauderdale recommends full tanks. Make sure you treat the fuel. Jerry jugs is what I do. Where are you hauling?

Thanks for the quick reply. we are hauling at Green Cove Springs marina, Florida.

[capn_billl]

I agree with above, I have seen stainless steel develop small holes at liquid level from condensation.