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

[chris07732]

I've used the typical fuel hose connectors on outboard motor gas tanks/lines for several months. I did take a small risk by using the 6 gal gasoline tank typical with outboard motors, made sure it was clean of gasoline and made sure I was the only person to fill the tank so someone didn't put gas into the "red" container. No problems running my 75hp diesel that way for several months.

Also, make sure of thickness of your steel tank walls. P.O. of my boat saw the rust condition on the tanks of my 50 yr old boat, said they were no good and proceeded to cut them out. The tanks were 1/4" thick, never would have rusted thru.

[boden36]

Regarding the line to a jerry can, I just have two lengths of diesel rated hose. The intake hose has a weight on the end so it sinks to the bottom of the tank. The fuel return has a double ended hose barb stuck into it. I just drop them in through the filler hole in the can.There is a bit of cord tied around the hoses so that I can tie them into the top of the can.
The can is tied to the boat's structure so it can't go walkabout.
The can is out of reach of spray or drips, so a plastic shopping bag stuffed around the top suffices to keep it clean.
When not in use, the can is closed and the two hose ends are joined together via the hose barb to keep dirt and moisture out.
With this setup you can use any convenient can of diesel, or change from can to can as you wish.
I would only use this setup with diesel, definitely not with gasoline.
Sounds very rough and ready but has worked extremely well for many years as an emergency backup tank.
See my earlier post as to how it all is plumbed.
Regards,
Richard.

[Shanaly]

if the rust is only on the floor, then you could pour in epoxy to say half inch deep, this would lock the rust and give you a smooth floor...you could also try epoxy primer from Phoenix Paints, perth W Australia, this is an aggressive epoxy paint, water based, which primes rusty surfaces - but you would have to get the big flakes off first.

[Delancey]

Thanks boden36, this is the kind of info I was looking for. Keep it simple works for me

Something tells me that even though you have this set up at hand, you maybe only used it once or twice and have hopefully since fixed the problem that helped you devise it in the first place.

Stuffing hoses in the fill spout eliminates the need for a fitting and provides for a vent as well. This isn't what anybody wants but it's a way to get you through and that's the point.

What height to you mount the bottom of the can relative to the engine? Above? Same height?

[mbianka]

Originally Posted by Delancy

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.

Delancy:

I went to electric propulsion and no longer have diesel to worry about. But, I did a lot of work getting it off the boat. My boat was a 1986 and here is some of what I did. First I had to empty the diesel from the fuel tank. Since you said the boats been on the hard for a few years I would get rid of the current fuel. Here is how I drained the tank:
THE BIANKA LOG BLOG: REMOVING DIESEL FROM THE FUEL TANK

Then I would get a small inspection camera and take a look inside. They are not that expensive and may help you inspect other areas of the boat:
THE BIANKA LOG BLOG: TOOLS OF A SAILOR: INSPECTION CAMERA

When I looked in the tank three years after I drained it I found a lot of tar and sand stuck to the bottom of the tank. I was a yikes moment. As this is the stuff that comes loose in a sea and can clog things up. Here are some photos of what I found:
THE BIANKA LOG BLOG: IN THE TANK: Part One, Scene of the grime!

In your case draining and a look inside it will give you a better feel for the direction you need to go before you head out on your trip and whether you need to find an alternative to the current fuel tank ASAP or can hold off.

[Cheechako]

I think you can count on it leaking into the bilge soon. Figure on replacing it for sure,otherwise dont buy it.