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Condensation in fuel tanks

I put the coach away a week ago and did all the winterization, except top up the tanks. The tank is about half full. I put diesel conditioner and bio additive in it. I am not sure whether condensation is going to be an issue in our cold dry winters in Canada but am wondering what the consequences will be if I leave it and get some condensation in the tank. What issues with starting am I going to run in to?
I have checked for mobile delivery services but they charge a minimum fuel rate ( I think I require about 90 gallons to fill) here in Canada so can I leave it??
Comments would be appreciated
Peter
Peter    Alberta Canada
'98 U320 40'  Build 5359 M11 450 HP, Aqua hot, Blu Ox

Re: Condensation in fuel tanks

Reply #1 –
Peter, I try to leave my fuel tank as full as I can before storing it or even parking it for a month or so.  With a cold weather additive and biocide added to a half tank you should be OK.  Run your generator with this fuel mix to make sure it is in the fuel filter and the AH as well for the same reason.  If you can run the AH and the generator once a month do so.  Leave the coach engine off until you are ready to drive it for 30 miles or so until it comes up to temp.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Condensation in fuel tanks

Reply #2 –
Peter,

Though in a dry climate, you have huge temperature fluctuations.

If you have "dry" air at 70 degrees F and the temperature drops to zero degrees F, two things will happen:

More outside air will be drawn into the tank as the temperature drops.  Then, as the temperature rises again with the next warm front, air exits the tank.  This repeats itself each heat/cool cycle.  Said another way, air is exchanged-- you don't just have the moisture in the initial air to consider.

So, it is not just the air that is in the tank that is in play.

The second thing is that cold air holds less moisture, so moisture condenses.  This water then goes to the bottom of the tank (water is heavier than diesel. It can NOT evaporate. Suspect this happens in your sticks and bricks house as well.

Not saying you have to fill the tank, but the more the temperature swing, the more it helps.

Were it me, I would use jerry cans to add 10 gallons at a time.  Consider it coach LOVE.

Good weight training.  BTW, we did this on the sailboat in many areas where our draft prevented us from approaching the fuel dock.  LOTS of weight training from dock to dingy and dingy to boat deck.

Yes, this is more "best practices".  Clearly, another philosophy-- "what I got away with" can be considered.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Condensation in fuel tanks

Reply #3 –
I agree that keeping the tank full is the best idea but when we parked equipment
for storage the tanks weren't filled and sometimes the equipment would be parked
for years and it didn't seemed to be a problem. We pulled the batteries and left them.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Condensation in fuel tanks

Reply #4 –
Go to any truck stop or parts house and buy some stabil for diesel. End of problem

Re: Condensation in fuel tanks

Reply #5 –
Quote from: dicksop –
I have checked for mobile delivery services but they charge a minimum fuel rate ( I think I require about 90 gallons to fill) here in Canada so can I leave it??
Agree with Brett.  I much prefer having a full tank in the winter because of big swings in air temp from day to night.

If it was me, I'd buy or borrow a couple 5 gallon fuel cans and make the required trips to/from fuel station until the tank is full.

But it's your coach, so DWMYH.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Condensation in fuel tanks

Reply #6 –
Quote from: moisheh –
Go to any truck stop or parts house and buy some stabil for diesel. End of problem


Sorry, don't see that "curing"  water in the diesel tank.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Condensation in fuel tanks

Reply #7 –
Remember: Nature abhors a vacuum. So it works on filling any void....like a fuel tank. Maybe not enough to fill it up but enough to cause you problems.
We have stored our coach, always with the 100 gallon tank full minus what we used driving to the storage (30 miles at 9 MPG) and have never had a problem when we picked up the coach in the spring.
Of course I did the additive thing per Brett Wolfe so I could sleep well at night.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Condensation in fuel tanks

Reply #8 –
Quote from: nitehawk –
Of course I did the additive thing per Brett Wolfe so I could sleep well at night.

Norm,

Really glad you are able to sleep at night.

I was awake most of the night concerned about that!
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020
 

Re: Condensation in fuel tanks

Reply #9 –
Thanks for all the advice. My shoulders are currently incapable of carrying fuel tanks because of surgery but as soon as that is better will give it a shot  The temp swings where I am in Canada are not that great. Once it gets cold it stays cold... 23-41 f. At the moment
Peter    Alberta Canada
'98 U320 40'  Build 5359 M11 450 HP, Aqua hot, Blu Ox