Disecting Big Duck - A Tankless Endeavor

Big Duck has two belly tanks. As far as I can tell they're the same shape/size, about 50 gallons each and I know the aft tank leaks and maybe so does the forward tank. They can be accessed via a hatch that runs the length of the cabin sole.

The red one is forward. They are both foamed in, witnessed by the bulges of foam on the right side of the picture. The tanks have been closed up, the fills have been capped off as are the feeds and vents. The effort now is to free the tanks from the foam and see if they can be rotated up out of the opening.

The first step was to make some work platforms.

I thought the easiest way to get the foam out would be with an electric knife...just cut out big pieces. This didn't work well. What did work was the back end of the claw hammer.

Hack out small chunks, then follow up with a 1/8" X 1" X 24" steel bar - slightly sharpened to scrape the remainder off the sides and bottom. A keyhole saw also proved useful for some places.

There was an interesting situation between the tanks. The area was filled/sealed with foam ensuring that any water (or gasoline) that worked it's way into the area had no means of escape. There is an area below the tanks that allows drainage all the way from the forward part of the boat, but it was completely sealed off with foam. So digging out the foam/sludge there got to be a messy job.

So now the forward tank is de-foamed.

 

The next step is to see if the tank can be freed from the hull, and if it can, will it be able to be extracted from the opening?

Before calling it a day, I wanted to see if the tank could be easily lifted away from the hull. I wedged a tack puller under the corner of the tank to see if I could encourage it to come up - maybe just a little?

More on that in the next installment...