Nasty Job but it worked
I tried cleaning fluids, suction through the fuel sender hole, fuel polishing. Nothing worked and I kept clogging my filters. So I installed an access hatch on the fuel tank. I cut a square hole in the cockpit floor lazarette and installed a lazarette drain hose to the outside (it needs to come from the engine compartment back to the cockpit side lazarrete. I cut a square access hatch in the aluminum fuel tank using a cutting disk after I completely drained, suctioned and vented the fuel tank. I found pounds of sludge (broken down diesel, algae etc) and completely cleaned the tank using acetone. I cut an aluminum plate with holes every inch. Used silicon sealer and screwed the plate onto the tank. I used epoxied marine ply to build a cover for the lazarette floor and sealed it with 4100 and screws. So far everything is working great, no water leakes into the engine, no diesel leaks and I have a way in the future to clean the tank if I need to.
