25 Year-Old Steel Fuel Tank - What to Do ?

[Delancey]

I'm looking at buying a nice older boat. One of the issues that concerns me is the 25 year-old steel fuel tank which shows some rust on the bottom. I can't see the full extent of the rust because of limited access but know it's there. Might not be problem but whose to say.

I am planning on replacing the tank eventually but would prefer to put the job off until later. It's a 28 gallon tank that's half full of fuel, the boat has been on the hard for a couple years.

Should I suffer through a bunch of fuel filter changes likely to occur during a late season delivery? Or just bite the bullet and get it over with?

Replacement of the tank will require some demo of the cabin interior and will take time away from other projects. That said, changing clogged filters isn't the end of the world, but somehow it seems to happen to me at the worst possible times.

[delmarrey]

Q: Is this gasoline tanks?
Q: Is this a power boat?

Reply: If it's plugging filters, it's time to flush the tank or replace it. Going dead in the water at the worse time could cost you the whole boat weather it be by a law suite, a sinking on the rocks or going under a bridge like I ALMOST did. Not good!

[Delancey]

Sailboat, diesel. I haven't had a survey done yet, just at the offer stage but thinking forward. Not expecting the seller to be negotiable on this one so it's on me to do it. The tank has a label say's it ASTM-A463 which sounds like spec for an aluminum, not zinc, coated steel.

Like I said it's obviously rusting on the outside but maybe it's fine on the inside. There is an inspection port I haven't opened yet.

If the inside is fine should I just drain the 15 gallons of fuel and clean it out? If you drain the fuel what do you do with it? Filter it and put it back in? Or instead should I fill up the tank to dilute the crud and then add chemicals?

[Boracay]

How much fuel do you really need?

Would it be possible to install a small header tank above the engine to feed the lift pump?

Most of the time we only use a few litres of diesel. Say 20 litres max in any trip. I've been very tempted to put in a 30 -40 litre header tank with some sort of electric lift pump from the main tanks.

Facing a delivery taking fuel from very old crud filled tanks I'd be even more tempted.

I'm thinking something like this.

[Delancey]

The delivery is from Connecticut to New Jersey via the East River.

Expecting I could sail most of the way I shouldn't need to run the engine that much, but when I do it will need to be reliable. Maybe I could bypass the fuel tank with a hose from a five gallon Jerry Can? Anybody ever done that?

[daddle]

ASTM-A463 is a specification for aluminium coated steel. The aluminium is gone. The tank is a danger to your happiness and safety.

[Chief Engineer]

Originally Posted by Delancy

The delivery is from Connecticut to New Jersey via the East River.

Expecting I could sail most of the way I shouldn't need to run the engine that much, but when I do it will need to be reliable. Maybe I could bypass the fuel tank with a hose from a five gallon Jerry Can? Anybody ever done that?

Many, but not all, diesels have return lines to the tank.

If it has a return line to the tank...you will be pumping fuel from your jerry can to it.

I would not hazard a trip with a tank like that.

[Weyalan]

Assuming it is diesel, I cant see why you couldn't draw from a jerry jug and return into the jerry jug as well.

[skipmac]

Originally Posted by Delancy

The delivery is from Connecticut to New Jersey via the East River.

Expecting I could sail most of the way I shouldn't need to run the engine that much, but when I do it will need to be reliable. Maybe I could bypass the fuel tank with a hose from a five gallon Jerry Can? Anybody ever done that?

I have run from a jerry jug but mainly when trouble shooting the fuel system but no reason why you couldn't do it for a longer stretch.

But you WILL need a reliable engine going through Hell Gate and the East River.

As mentioned, don't forget the return line as well.

[Delancey]

Thinking about going through Hell Gate and the East River is what got me started on this changing the fuel tank thing. Maybe it would be best just to replace the tank, if I did then what do I do with the old fuel? Give it to someone who uses fuel oil for heat? Give it to a truck driver?

Or maybe the best thing is to just sail to the western end of long island sound and call SeaTow to get me the rest of the way to Jersey City? Then I don't have to deal with the fuel tank until next spring. What does that cost?

[boden36]

I have a permanent system on our boat which consists of two filters and two cocks. One set of fuel lines is loose and can be dropped into any fuel can that's convenient at the time.
I have the choice of drawing from my keel tank, and returning to the same tank, drawing from a jerry can and returning to that can or cross directing my return.
Regards,
Richard.

[delmarrey]

Originally Posted by Delancy

Thinking about going through Hell Gate and the East River is what got me started on this changing the fuel tank thing. Maybe it would be best just to replace the tank, if I did then what do I do with the old fuel? Give it to someone who uses fuel oil for heat? Give it to a truck driver?

Or maybe the best thing is to just sail to the western end of long island sound and call SeaTow to get me the rest of the way to Jersey City? Then I don't have to deal with the fuel tank until next spring. What does that cost?

The Solution to Pollution is Dilution. You can give the fuel to someone with a large home heating oil heater or recycler and they will use it.

As for the return line to a jerry can. Make it metal if you can. Returning fuel from a running motor picks up heat along the way and depending on the size of the tank, may start getting warm and dispel fumes. So, keep that in mind when deciding where to place it. You may want to put in a vent line so it can breath both ways.

Sea Tow can give you an estimate if you know the distance and time of day. If you do get towed use a small drogue to keep the line tight between the two boats, if they need to be close together.

[Bloodhound]

The tank needs replacing so why not now? Why wait and take a trip not knowing if the fuel supply will be constant. As with most equipment, it conks out when it's being used (needed) so why put yourself through a heart-in-mouth trip. Personally I would not do the trip with a shitty tank of stirred up fuel. If the tank is that bad, it could even split a seam during the voyage (as one did on me) and all the fuel's in the bilge and none in the supply line, or the tank either. Risk it if you want, but not for me.

[gixerjen]

I'm having the same issue with the boat I've just bought....... only mine has sprung the leak. Believe me, you don't want a bilge full of diesel - I'm not sure if I'm ever going to be able to get rid of the smell!

My tank's bonded in so (because there's plenty of room in there) I'm just going to sit a plastic tank next to it for the time being.

[Jim Cate]

Being an experimentalist at heart, I would take the boat out in some choppy conditions, let her buck and roll for a while, and then sample the fuel. Seems like this should answer the serviceability question pretty directly.

And IMO, it is quite possible that it is less rusty on the inside, especially if it has had exposure to salt water on the outside. Typically the water on the inside is fresh and thus less corrosive than what drips on the outside. Anyhow, use the inspection port to determine the actual condition before destroying your joinery chasing a chimera.

Cheers,

Jim