Full Fuel Tanks???

[Chips]

I live aboard a 1973 43 DCFB... DD 671N's... 400 gal fuel capacity. I have hear5d pros and cons about keeping fuel tanks filled... any feedback is appreciated. Also, what about adding a biocide, such as Biobor? I add when adding fuel, but should I be adding as maintenance every so often? I have not added fuel since last November, and have slightly over half tanks...

[Fanfare]

When I put Fanfare away for the summer in two weeks or so I'll fill the fuel and water tanks to the top. I add Biobor with the fuel fill. One bottle is good for 600 gallons. This is the only time I use Biobor. When I am running the boat I figure the Racor filters do a pretty good job of cleaning and removing water. The Biobore just prevents algae from multiplying in the fuel/water interface. So far this trip in the Bahamas I have used just short of 1,000 gallons of diesel. There is not a drop of water or debris in the bowl of my Racors which is a good sign. The only time I have had an algae problem was after taking on fuel right after the fuel boat had filled the almoat empty marina tanks. I think this stirred up the crud in the bottom of the fuel tanks and also perhaps emulsified the water in the tank bottoms. Now I give the marina 24 hours to settle before fueling. If you do have an algae problem I think there is nothing to do but have the tanks professionally cleaned.

Because my boat summers in Florida I want her heavy in case of hurricanes. When Wilma hit a year or so ago the area where Fanfare lives was without electricity for about a week and water for a few days. I was happy to be able to tell the guy who cares for her to move aboard if needed. When I come down I dump last year's water, sterlize the tanks with three cups of Clorox added sequentially as my three tanks fill, rinse after a few hours, and I'm good to go.

[spartonboat1]

I live aboard a 1973 43 DCFB... DD 671N's... 400 gal fuel capacity. I have hear5d pros and cons about keeping fuel tanks filled... any feedback is appreciated. Also, what about adding a biocide, such as Biobor? I add when adding fuel, but should I be adding as maintenance every so often? I have not added fuel since last November, and have slightly over half tanks...

Curious, since I have a '72 DCFB w/the 671N's. Have you measured your tanks and truly have 400 gals capacity or do you have the twin 185 gals at 370gals total. It so happens that my tanks measure 1" of fuel per 10 gals, so that makes it handy/helpful when judging remaining fuel and fuel needed to fill up. 18"'s is 'full', 9"'s down by half, etc.

[Chips]

The original owners manual states 400 gals, but I was told by seller 370... bottom line is, I'm not sure... I like your measurement technique.... my tanks were recently replaced...

[Trojan]

The original owners manual states 400 gals, but I was told by seller 370... bottom line is, I'm not sure... I like your measurement technique.... my tanks were recently replaced...

Replaced with what? How did you get them in?

BILL

[spartonboat1]

The original owners manual states 400 gals, but I was told by seller 370... bottom line is, I'm not sure... I like your measurement technique.... my tanks were recently replaced...

Why were your tanks replaced? They are practically as tough as steel. Did you have gas engines and suffer the ethonal issue? Curious...

[REBrueckner]

100 gallons of fuel weighs roughly 715 lbs...like four of five people

Full fuel tank pros:

In freezing weather, full tanks help prevent condensation in the air pocket,
If you live aboard you always have fuel aboard for heating or traveling...
may stabilize the boat a bit in wind and waves


Full fuel tank cons:
If you don't use the fuel it could begin to deterioriate,
(This happens faster in warmer tropical climates),

full tanks put unnecessary strain on the boat during haul out,
Not as easy to take advantage of lowest prices for fuel....
May not be as efficient running as you are lugging extra fuel with you.


I prefer to fill up when I get to a source with a good price...helps them and me...


Water: I don't have a strong opnion, but I'd tend to leave the tank empty...to make it easy to flush through when recommisioned....in fact I think I'd leave the tank (almost) empty with some clorox added to keep it as clean as possible.....why let stuff grow and accumulate and then subsequently try to flush it out prevention seems better.

[Genesis]

Biocides are HALIDES.

Use ONLY when necessary and then STOP. Long-term use will impact injector life.

If there is no water in your tank there will be no biological growth. It is not algae, it is a bacteria. Algae require light and there isn't any in a fuel tank.

[boatwright]

just a note on water tanks . if you have stainless steel tanks high levels of clorine can react and damage your tanks. had a dock mate store his shannon sail boat with heavy clorine solution for the winter, in the spring he needed three new tanks. good for rinsing not for storage

[Chips]

Why were your tanks replaced? They are practically as tough as steel. Did you have gas engines and suffer the ethonal issue? Curious...

I was wrong... checked further and found the WATER tank was replaced by previous owner.... I have 671-N's...