Cleaning Out Diesel Tank

[S/V Alchemy]

Basically sponges lashed to a length of lumber with a taped-on Maglight, yeah.

If somebody makes 'em like that, I haven't seen it. Used to be called "a swab", however.

Good luck with a mucky job.

[theway]

Ok, first tank clean. Here are some photos and notes

- The tank was filled with crystals, no gunk or bio-stuffs. Can anyone explain this to me? Please see attached images

- I went through the inspection plate, but a mirror was no real help, I used my phone to take pictures to see inside.

- I used the heavy duty paper towels, $2 for a roll of 68
I changed the sender while I was at it, it hasn't worked since I owned the boat.

- I did not use any chemicals just the left over diesel

- There was about 5lts of diesel still in the dank even though the engine couldn't pull anymore and was technically empty.

- Does anyone know what the water clean out is for? It's the slanted rod on the inspection plate.

[DeepFrz]

It cleaned up very nice. I have never seen crystals like that. They would do a job on your filter if they got sucked up in heavy weather. Could be result of some kind of additive but that is just a guess.

Water removal tube probably goes to the lowest point in the tank so that any water that settles out can be pumped out with a squeezable fuel pump, like on an out board engine.

[Nicholson58]

I swabbed out the tanks with rags and then used GoJo or equal without the pumice. Apply witha pump sprayer and soak over night. Then I used a high pressure washer and a sjhop vac to collect most water. (The bottom ports were disconnected). Next, I wiped down the inside with mineral spirits and rags. If you don't plan to disconnect the fuel lines I would skip any water based cleaning. Use rags and mineral spirits. When you are done, check your deck port and be critical of your O-rings/gaskets. Water sometimes finds its way in there.

[cheoah]

Hi Austin, has that fuel been exposed to cold temps? Like 15F or lower? I know that cloud point is around there, where paraffin molecules start to separate out and make visible crystals. What I don't know is if they always reabsorb, or if an additive is used, if it could affect crystallization or reabsorption. DeepFrz might be right that it is an additive, or maybe something picked up at a fuel dock. Something from tank manufacturer?

The water cleanout looks handy, for pumping out - especially if you got a lot of water in there, but you're going about it the right way, opening it up. I Hope it solves your problem.

[cheoah]

Just read something about fatty acid based lubricity improvers interacting with salt....and then there's resin formation in old fuel....

who knows. Curious though..

[theway]

Yeah my guess was additives too. I've used 2 different ones over the past 2yrs. The boat has been in cold temps back in 2010, winter in Georgia. But who knows, the tanks probably haven't been cleaned in over 15yrs.

I bet those darn crystals clog my filter both times... once in a gale near Jacksonville and the other in the Delaware Bay when the current shifted and the wind picked up, i was in route to cape may. I feel a lot better now, just need to do the aft tank. Thanks for all the insight folks.

[DeepFrz]

I might be a good idea to drag a small piece of cloth through the fuel line to make sure there aren't any of those crystal hiding in there. You will use your motor with much better confidence when the know the tanks are clean.

Good job.

[rebel heart]

No idea on those cystrals man. Clean tank = peace of mind.

[SurferShane]

Best thing is to consistently use a diesel conditioner; prevention is better than cure?

[Surfer Girl]

Nice job on the tank clean.....

Just a thought, how old is the fuel hose from tank to Racor to engine? Fuel hose is cheap and old hose is a bit like stainless wire standing rigging - might look good on the outside but can suddenly fail. Since you worked so hard on cleaning the tank, changing out the fuel hose is relatively easy and will complete the job.

[theway]

Looks like to Fouts to clean the fuel hoses. I tried to take one off not too long ago was pretty tight and didn't want to come off. I was thinking I could just squeeze parts of the hose with a pair of pliers and listen for any crunching or feel for resistance. It seems that if anything were in the hose it would already be sucked into the filter.