diesel tank contamination/bug

[paulburgess]

I'm getting recurrent probs w black slime deposits and some water, in the main filter bowel and I can see scattered black slime in the tank looking down the filler with a torch. I've tried siphoning the (steel) tank nearly empty but the outlet (on the bottom) has a pipe rising up from the bottom so can't empty completely. I've also put in Biodiesel treatment and some fresh diesel from a petrol station. Wondering whether I should get the tank properly cleaned? Steam-cleaned? -if so who does it (in Solent area) and do I need to remove the tank from the boat to do the job properly (and then put in all new fuel lines and the other little filter on the engine)? Where should the fuel tank breather pipe go to? It shares a final outlet to the hull with a breather from a holding tank -doesn't seem like a good idea!

 

[lw395]

If you can remove as much water as possible from the bottom of the tank by 'hoovering' it with a pela oil extractor, you should be able to reduce the crud content to something your filters can easily cope with. A larger bore hose on the pela, as the supplied on blocks easily, and plenty of pastic cans for the dirty diesel extracted are good ideas.
If you let the dirty diesel settle fro a few days, the top fraction can go back in the tank.
I use plastic milk containers for the diesel to settle in. Be warned that the caps don't seal that well!
Hope that helps.

 

[Eygthene]

My fuel tank breather exits near the top edge of the cockpit, well aft. On the only occasion that a small overfow occurred, a tiny drop of diesel spilled into the cockpit and went down the cockpit drain (don't try this in your home marina!).

If the fuel tank breather shares the skin fitting with the holding tank breather, what will stop any overfow from the holding tank finding its way back down into the fuel tank? Not a good idea at all, as you suspected!

John

 

[paulburgess]

Thanks guys