View Full Version : Cleaning the fuel Tank

S/V Laura Ellen
06-14-2009, 05:22 PM
Today I tackled the task of cleaning the fuel tank. After 70 years of service the tank needed some TLC.

The tank is a copper with soldered seams.

My idea was to cut a 5" hole in the top of the tank so that I could get in and clean it. So after measuring a couple of times and carefully working out where the inspection port should be located, I cut the hole. To my surprise the tank has two baffles in it so I need to cute one more access hole. (one compartment has a hole for the fuel line). Back to the measuring tapes for more careful measurements, and I cut the second hole.

Once the holes were cut it was a simple task of power washing the tank inside and out (making sure to contain the oil). As you can see in the pictures, some oil escaped but the contaminated gravel was cleaned up for proper disposal.

Top of the tank showing the access holes for cleaning the tank.

Aft end of the tank

The tank showing the in-board and bottom side of the tank.

The valve at the low point of the tank was for the fuel supply to the engine. New fuel pickup return and vent line connection will be installed before the tank is reinstalled.

The access holes will be covered with a piece of polyethylene sandwiched between bronze rings and gaskets.

While the tank is out I will probably get it steam cleaned, just to be sure the tank is spotless.

And in case anyone is wondering, I will not be polishing the copper. :D

06-14-2009, 07:01 PM
FYI I just happened to have three of those for water tanks. Actually, that's past tense - "had" ...

sailordave and Lefty tested mine and the solder came back positive for lead. Not that you should be worried about lead contaminating your fuel, but just be careful with the cutting and clean up... ;)

That's a pretty custom piece and you've already got a fair amount of time invested in it, but for anyone that stumbles on this thread later, even custom size tanks are quite economical. There must be a computer program that cuts the pieces and molds them because I was looking at about $400 for a new custom stainless tank for Sarah. In the end we found a long rectangle one that fit just fine (West Marine +/- $300).

So for the folks researching cleaning fuel tanks, just factor in however many hours of your own time plus parts - new gaskets, inspection ports, fuel pick up, etc. fixing up an old tank when a few hundred dollars brings a brand new one to your door...

YMMV but I like knowing that Sarah's, which is in a gosh awful inaccessible spot, isn't likely to cause me any grief. :)

Now back to work for you Alan - you've got a boat show to attend in a couple of weeks...

S/V Laura Ellen
06-20-2009, 07:17 PM
Started the task of replacing the timing cover gasket and oil pan gasket.

The oil pan removal went well, but I did uncover the source of the leak. The front corner of the ban was badly corroded.


The removal of the timing cover gasket didn't go as planned. I'm having problems getting the nut on the crank pulley loosened.

06-21-2009, 06:16 AM
That nut is tough on any engine. A big socket and a breaker bar are required. If there are holes in the pulley lash it to a nonmoving part to keep it from turning.
Put down the wrench when you get frustrated.

The Bigfella
06-21-2009, 06:46 AM
The torque on that crankshaft nut can be in the hundreds of foot pounds range... check the specs for your engine. It might take all your weight on an 18" bar to get it undone. Last one I did was undone with a very very grunty air tool with 3/4" drive.... gotta make sure you get the direction correct too.