my question of the week re: fuel

[Ken Heyman]

So I need to pump the remaining fuel out of my tank this fall while on the hard. (I need to retrieve a fuel sender that fell in but thats a different story.) That part is easy as I have done it before using a siphon technique albeit this time I will do it from the cabin using the electric fuel pump and a disconnected pump "out" line and a new line fed into Jerry cans. That is not my question

My question is this: Should I put my 'polished" fuel back in and then refill the tank to "full" to minimize condensation. Yes I will use fuel treatment biocide etc. although the pumped out batch has already been treated. In the alternative I could leave the tank empty and refill in the fall (probably with fresh fuel). In the past I have had no problem with the previous seasons fuel and my tank has full or almost full.

So full or empty. Please cast your votes and comments.

thanks,

Ken

[Ron Hill]

Ken :  No vote, but here are my thoughts:

If I were in your situation I'd empty the tank, remove the tank, retrieve the drowned sender and then clean the tank while you have it out of the boat[/b].
Look at my Mainsheet article on that topic of removing the fuel tank and cleaning it.
 
Whether you do it this fall or spring is your choice, but If you wait till spring just make sure your tank is full.

In any event, do NOT add more biocide to the biocide-ed fuel that you already have. 

[Stu Jackson]

Fuel tank condensation

Aha, finally a guinea pig we can work with!!!

For years and years, there have been repeated discussions about whether or not fuel tanks should be full or left partially full during off season periods to avoid the dreaded condensation issue.

I have recently posted, somewhere else if not here, that the surface of the fuel doesn't change much between a full or partially full tank (putting aside for the moment that our tanks get narrower at the bottom).  So, following that theory, it shouldn't much matter because there's the same surface area of fuel for condensation to form upon.

A response to that was that the walls of the emptier tank would provide more surface area in a partially empty tank and create more water in the tank, regardless of the surface area of the fuel.

OK, now that we have your attention:  with your empty fuel tank, leave it empty in the boat, and report back to us in the springtime how much water you collect in your tank.  Litres, gallons, ounces, six packs or [Chianti] wine bottles, doesn't matter much either way.

I just can't wait for the answer.     But I guess I'll have to...

[Ken Heyman]

Thanks Ron and Stu,

Ron I did remove and clean my tank a number of years ago using the "Hill" method and since then, my filters have remained unclogged. Accordingly. I don't think my tank is due for a removal/cleaning. If I do decide to leave the tank empty, I wonder if i should still use the fuel that i have removed, next season. Obviously it will be no better or worse than when I leave the tank with fuel for the winter. 
In this case it would be sitting in  Jerry cans or maybe some empty antifreeze bottles for the winter. There may be more condensation risk in storing fuel that way than in the tank? Perhaps I will see if a trucker wants some recently polished fuel.

Stu, If I empty as much fuel as I can using the pump, I guess the only way I can test for moisture other than observation and looking at  my Racor bulb (when a new filter is installed), would be to compare hydrometer readings pre winter and post winter.

I need a boat in a warmer climate !

Thanks guys,

Ken (the "New Guinea Pig"

[RV61]

Ken.
One question comes to mind. Any way to fish the sender out with out emptying the tank?

If it were me if the fuel comes out and looks good and tank is still clean I would retrieve  the sender and put the fuel back in as I would not want store it, move it. or otherwise change the way I  store the fuel wich is in the tank. Been working well this way for ten years why change. This also seems to be less work then storing.

 If one were to store the fuel outside the tank I would check fuel in spring before putting back in the tank to see if anything is growing. Would be concerned about using the empty antifreeze jugs if the are clear as light could promtoe bacteria growth also do not know if the plastic is compatible with diesel. I know if I put deisel in a plastic solo drink cup the cup will melt. Would also check tank again in spring if left empty to see if anything new was growing before adding fuel.   

 

[Ken Heyman]

Good question regarding fishing out the sender. I have already tried- spending more time than i care to admit doing just that. I have talked to the mfg. regarding magnetic properties of the sender. They insisted that a magnet would attract it. After I tested on a piece of sender bracket, I told;d them they were mistaken and they fessed up and told me that they were referring to a different model. I tried grabbers, rods, etc. --no dice. I think that once the fuel is out I will be able to move the tank and get the sender in a retrievable position.the factory did admit a manufacturing defect that allowed this to happen and I should be getting a free replacement. As far as storing fuel I will likely stick to Jerry cans or immediately refill the tank. The only reason not to refill is to save my back until spring and of course be the test case for an empty tank all winter which I have never done. If i refill i will have to buy and lug another ten gallons of fuel.

Thanks much,

Ken

[Gary]

Ken,

A good way to reuse / recycle diesel fuel is through your home oil burner. Then start with fresh fuel in your C-34 tank.

Gary

[Ron Hill]

Ken : A couple of points.
1. You only get condensation in a "vented tank".  If the jerry can is sealed and full, no condensation.  If you see condensation on the top of your boat - the same is happening inside the fuel tank in the airspace above the fuel level!!  The warm fuel like the warm surface meets the cool moist air and  - condensation.
2.  I you remove the fuel and then remove the tank it will be much easier to shake the tank upside down and get out that drowned sender.
3. You could just let that sender rattle around in the bottom, as it surely is pickled by now!!

A few thoughts

[Ken Heyman]

Ron,

All good points. I concluded during the season that the sender was unlikely to cause me any difficulty and in fact it did not during the season. Nonetheless-with Murphy out there, it is probably a good idea to remove it. I never really thought about the vent being a contributer to condensation. that being the case, why not seal the vent during the winter and non-use periods ?

Thanks,

Ken

[Mike and Joanne Stimmler]

Hi Ken,
My vote is that once you get the sender out, put the polished fuel back in and fill the tank to keep out condensation. My understanding on the condensation issue is that the surface area is not what determines the amount of condensation, it's the volume of air in the tank that contributes to condensation.

Mike

[Indian Falls]

I may be saying the same thing in a different way but it seems to me a few points were missed.

The condensation is from the moisture content of the air inside the tank.  You let air in when you remove fuel. Some air may in/out the vent with expansion during temp changes but the vent line being so long I don't believe there is that much outside air entering the otherwise closed up tank.  If you could fill your half full of diesel tank the rest of the way with dry nitrogen displacing air containing humidity, there would be no condensation inside the tank no matter what temp you're at. 

The other point is the algae growth occurs at the interface between water and fuel.  No water drops in the fuel - no algae growth.  So if your jug is full of polished fuel and full to the top. No condensation or algae growth can occur in any significant amount.  I pulled my tank a few weeks ago and found no appreciable water present, I've been at 1/4 tank for 2 years.  The pickup tube is right on the bottom and I'm not getting loads of water in the Racor. 

I would store your fuel in jugs in the garage and fill'er up in the spring when you want to use it.
A little water will always be in a fuel tank so just count on the Racor to do it's job. 

By the way I was surprised to find that only one end of the tank is secured to the boat.  The vented/fill end is free to move up and down if the boat goes upside down... which I try to avoid.

[Ken Heyman]

The fuel (about 10 gal ) is now sitting in two Jerry Cans on the boat. In that my garage is not heated I will likely leave them there until I refill. Yes, it is polished fuel. I haven't inspected the Racor yet to see how much water was pumped through. I still need to go fishing for the sender which of course is the reason I am in  this ridiculous mini predicament. It was 27 degrees Fahrenheit today so I might as well wait until it gets down to single digits to make my assault on the tank----might as well really be uncomfortable.

---thanks much for the suggestions.

Ken

[SD Diver]

When I replaced the tank in our boat I too was surprised to find the tank only held in place be four wood screws in the forward end of the shelf it sits on.  But it has not fallen into the aft cabin or through the out side hull yet so I guess it's ok.  When I put the new tank in I put down a layer of oil absorbing pads for the tank to sit on, kind of cushion it just a bit.

Ralph
Ciao Bella

[Indian Falls]

1.) Would it be a waste of time to but a ballistic nylon strap on the aft end of the tank?  Something similar to battery hold-down straps.   

2.) What would be the best cushion to place beneath the tank?   I'm leaning away from anything that can absorb fuel and be non removable unless you remove the tank again.

Alternative Cleaning method:  I bought a 4$ bottle of Mean Green from the dollar store and put that with a gallon of water in the tank.  I left the tank in my truck for 3 weeks and went about normal business until the temp started getting around freezing.  This won't ''scrub" anything obviously, but it did dissolve all the slimy stuff (algae I think). Anything that's not coming off from this treatment,  I'm not going to worry about.  A good hot water rinse ought to finish it off.

PS: I'd use a "fish tape" with a hook bent on the end (stiff square wire used by electicians) to get hold of that sender.
The first baffle is about 10 inches away, the sender will be stuck in that fwd compartment.

[Ken Heyman]

Hopefully the worst is over. I climbed up into the boat today to take a gander inside the tank from inside the aft cabin. With a mirror and a flashlight I was readily able to spot the float element at the end of the sender lying along the bottom, front, starboard surface of the tank. Tried snatching it with a hanger and then a Ace flexible springloaded grabber.--Nada. I think I need something that will fit thru the tank opening, is easy to manipulate and short enough to not run afoul of the aft cabin ceiling. Maybe I will try the "fish tape" but a pliers type grabber would be best snag the float arm.
, mirror and tool all at once.I can tape the light and mirror in place (maybe)  I did have my wife hold the light from the cockpit access but the visibility wasn't very good.
Ken