I've never tackled a fuel cell before. CSX4158 has a fuel safe cell, which uses a rubberized canvas bladder with foam inserts. There's no sending unit, but we may add that.
A call to FuelSafe was rewarded with helpful advice. Rather than toss it altogether, they suggested complete disassembly and inspection. The foam and bladder can be washed and reused. Here's how you take one apart:
Drill out rivets with a very shallow bit, or grind off heads. There's a strip of heavy urethane taped behind the rivet heads to prevent them from rubbing the bladder, so you do have some wiggle room.
Another cobra pee shot...
After draining, remove side plates, drain remaining fuel and lift out bladder.
There's a little mud in the filler flap assembly. About 50/50 dirty water/fuel mix in the tank. 10 gallons worth!
Tank is pretty simple otherwise. Seams are protected from burring with heavy tape.
There's the foam elements. Open cell foam washes easily at the carwash and once dried out, shows no signs of dirt.
"I love that dirty water..."(Anybody from Boston?)
Tank cleaned and ready for reassembly.