Clean Diesel

First draw off some fuel into a clean glass container. Hold the glass/fuel between you and strong white light. If there is a distinct haze (or worse) then the fuel is particulating (agglomeration/growth) of bio-particles/slimes of cellular debris plus some oil decomposition. If so, open the tank inspection port and look for the deposiition of fouling on the tank walls. Just use your finger , go down through the oil as far as you can go and feel for heavy 'slime' on the walls. (Others have posted use of manual dip tube to test/remove the free water - good idea.) If the walls are found to be heavily laden with 'goo', consider to drain ALL the oil and take it home to burn in your oil heater; then clean the tank walls by mechanical scrubbing, etc. until all the 'goo' is removed. Simply scrub all the goo to the bottom and then sop-up with paper towels, etc. then burn. Once bacteria and fungi begin to grow you have to clean the tank. DO NOT add biocide at this time as this will simply release the cellular debris from the tank walls; biocides are for prevention of growth. If you add biocide to a fouled tank you will create a monster that is very difficult to clean up and will make the cleaning much harder. Once the the tank internals are relatively clean and most of the 'goo' is removed; THEN, consider to 'recirculate' or 'polish' the oiil through filters. Recirculation filtration WILL NOT remove the debris from the tank walls if it has formed; and, will rapidly consume a lot of expensive filters ... and will not clean the tank --- a simple Racor filter only holds about 25-30 grams of debris. You will need to scrub (or steam clean) the tank walls to get all the 'goo' loose if you have developed a large accumulation. Diesel fuel tanks in boats should be cleaned every few years anyway to prevent the release of the biofilm and particle agglomeration from the tank walls. If you do have such contamination and dont physically remove (scrub) the particle deposition from the walls .... a heavy sea state WILL do it for you. ;-) Best storage means is to - totally REMOVE the oil when the boat is not being used for long term, especially in warm weather. If the tank is relativelly clean and the tank is PRESSURE/VACUUM rated (rarely are) is to put a valve on the vent line and simply CLOSE it when the boat is not in use. Third choice is to apply a large desiccant packed 'chamber' to the vent line to remove the moisture when the tank is 'breathing' due to thermal differences of the oil and the ambient atmosphere. The last choice is to fill the tank completely ..... but moisture will continue to 'drive' into the oil due to chemical/physical 'equilibrium' until the oil is 'saturated' with water vapor which eventually becomes 'free' water'. To keep the tank clean for the longest possible interval ... only fill the tank with the amount of oil you NEED plus a bit of 'reserve' for emergencies. Buy your fuel from a high turn-over source such as a depot that caters to 'watermen' ... or a truck stop; fuel from marinas that dont 'turn over' their oil often is probably already saturated with water. :-) In article <1171090124.250613.201850@l53g2000cwa.googlegroups.com>, map <mboater5@aol.com> wrote:

Wayne B

(still relying on Biobor, heavy sea states, a full case of *large*, fresh Racors, vacuum guages, parallel filter valves, due diligence, etc)

This one is supposed to be a sportfisher. Did GB make a sportfisher?

I couldn't find anything specific about it.

John H

I don't remember it...

Good luck. From what I hear, if you can last 120 seconds, you're right up there with Air Force pilots. -- ***** Have a super day! *****

John H

Oncce you start pumping you'll soon know what's hiding down there. I use a longish bit of copper tube attached to the pump with an angled cut at the bottom, and pump into a transparent plastic bottle (big one). The angled cut allows the pipe to rest on the bottom of the tank without blocking - this system gets much deeper than the fuel take-off. Most likely you'll find some water, and at the interface with the diesel, black slimy bits. If you're lucky, it's water only.

Empty all the water and as much diesel and slime as you can. Then rustle around the bottom of the tank with any sort of brush you can get in to stir gunge off the tank bottom. Pump again. Keep repeating til the diesel runs clean.

In extreme cases, when there's really too much gunge scraping off the bottom, you may have to consider steam cleaning. At that stage you need good access to the interior of the tank. With luck, you won't have to go that far.

Only then consider the enzyme/antibiotic/any other treatment.

If you have any doubts about how well you've done the cleaning job, either fit a parallel fuel filter so you can quickly change when one blocks off, or have a pressure drop warning across your filter to tell you when to change . .. .

Best of luck. Keep us posted!

JimB http://www.jimbaerselman.f2s.com/ Compares the cruising areas of Europe, with detail on Greece and N Spain

Tom in Connecticut One who wonders about a lot of stuff.