Is my fuel tank clean????

[SWIFTWATER KID]

Just bought a project boat....... 1985 Star craft Islander 22 ft.......
has a 40 -50 gallon built in fuel tank at mid hull.....under the floor......
boat has been neglected.....just a hull.....no engine.....
My Question: how can I determine the level of clean inside the tank ?
Pour in something ? a bore-a- scope ?

 

[ondarvr]

The sending unit should have a small panel that comes off, not much room, but you should be able shine a light in or use a bore scope if you have one.

 

[BlueBell]

Syphon or pump out what's in the tank and have a look.
Be sure and syphon/pump from the bottom of the tank especially if there is a trap.
Is it a steel tank?
If the boat has been neglected and it's a steel tank, just replace it.

 

[Mr Efficiency]

No mention is made of the material, I would guess it is aluminium. that being the case, the internal "cleanliness" is probably not what should be the main concern, corrosion issues, especially on the outside, could be more troublesome. You can employ fuel line filters and traps to catch any debris left in the tank after you flush it. I'd be inclined to pressure test the tank with a tiny amount of pressure to either the breather or outlet, after blocking other openings, to see if it holds, you can use a few pumps from a primer bulb to do this. But not much, just a slight overpressure. That way, any holes in the tank will be revealed, rather than finding out the hard way after filling with fuel.

 

[SWIFTWATER KID]

Thanks for the advise......all good stuff.....aluminum tank is bone dry as near as I have been able to determine......one stranded sailor in the area suggested a half dozen jugs of a product called Heat poured into the tank.....swill around a bit and see what comes out.....When I bought the boat the filler cap was in place and looked as though it was ready for fuel.....but my years of murphy's law tells me not to be so sure.......will proceed with due caution ! thanks again..........

 

[gonzo]

Heat is mainly methanol. It will corrode your tank if left in it.

 

[Ike]

all good advice. Pressure testing the tank is the most important step. Do not use more that 3 PSI, and it should hold that for at least 15 minutes. If it is not holding use a soap solution (not dishwashing or laundry soap, go to a propane dealer and get leak testing solution) around gaskets and fittings. if it bubbles it is leaking. If you don't get bubbles around the fittings but it still won't hold pressure the leak is in the tank itself. Don't try to repair it. Replace it with a new tank. If you are not confident about testing it yourself have a marine repair shop do it.