I had discovered a diesel
leak on my Gulf 32 that only happened when the tank was full. The tank on a Gulf 32 is 70 gallons, as is the water
tank, which is part of why they are such great cruising boats for the NW where you often have to motor
due to strong currents and fickle winds.
Anyway, the tank is also enveloped in a fiberglass
blanket on all sides and bottom, and is suspended up off the bilge
floor and keel
by this fiberglass
I had determined that the leak was not from any leaking hoses or fuel
fittings. It had to be from a leak in the tank itself. This tank came with no inspection ports
, and the small hole for the tank sender is too small for getting a hand in. I had also fouled a few fuel
filters too quickly and knew it was high time to clean out accumulated junk.
So today I launched into the project
. My first step was to remove the remaining fuel. I had already run it down as far as I dared, to just about on E. I had never run this tank to E before and didn't know how the sender read. As we all know, every car tank reads E quite differently. Anyway, I brought my three 5 gallon diesel
containers and started filling them from the fuel pump
hose I pulled off the motor
. I thought, maybe 10 gallons of the 70 gallons would remain.
I pumped out 10, and then 15. Damn. I had to run to the local hardware
store and bought two more 5 gallon cans. I was astonished when those filled and I wasn't empty yet. I ended up pumping out an additional 3 gallons for a total of about 28 gallons when the darn thing started out just above E. Well now I have learned how my gauge reads!
The tank on a Gulf 32 is below the cabin sole
and steps down from the galley
to the dining area. Removing the tank would be worse than horrible. So I cut access holes today in the front and back. The tank is baffled and has three compartments. I can't access the middle compartment unless I cut through one of the baffles.
I found the tank bottom to be fairly coated in sludge and sticky goop. And a thin layer of water
. 27 year old tank, so no surprises.
I'm happy to say I found a pit in the tank in the bottom of some of the sludge, which I had to scrape off with a razor blade. That pit allowed fuel to fill the envelope, and since it maintained the level of fuel in the tank, it only overflowed the envelope and leaked out when the tank was full.
So I am going to clean the tank thoroughly and use some flame master product to fill in the few pits and depressions. Only a few exist.
My question here is how you might go about cleaning
those pitted areas. I'm thinking a good roughing up with 100 grit sandpaper would give it a good texture. The actual hole is only the size of a pencil lead.
So how would you clean this pitted area to prep it for a tank sealant