Cleaning Fuel Tanks

[Andy G]

Well as you can see from the photo's, the combination of low fuel tanks and a large swell on the nose stirred up some lurking nasties in the tanks. the main fuel filters took a hammering, thank god for secondary filters.

Obviously I can't ignore this, so have scheduled to have the tanks flushed out. The situation is a common one I guess for boats of this age. The mild steel tanks are original, circa 1980's, some rust on them etc.

If anyone has already been through this I would appreciate any tips or advice before i haul the old girl out.

Thanks

Andy

 

[Tom.B]

Did this last year... ish.

http://www.trawlerforum.com/forums/s31/skinny-dippins-tank-cleaning-trip-report-6551.html

 

[jwnall]

Ugh! Ugly indeed! My two cents, for what it is worth: "Keep full fuel tanks!"

 

[Andy G]

Thanks for the link to your previous post Tom, an interesting read.

A question."The final step was to give the tanks a final cleaning with the scrubbing rig. two 2" hoses went into each baffled section of the tanks."

What was the purpose of the Two 2" pipes, were you pumping fuel back in or some type of water hosing to effect the cleaning.?

Ugh! Ugly indeed! My two cents, for what it is worth: "Keep full fuel tanks!"
__________________
John

Yes, I plead guilty as charged M'lord

 

[Bay Pelican]

Andy

With your tanks is the fuel supply feed to the engines from the top (pick up tube ending an 25/40 mm above the bottom of the tank, or is the feed from the side/bottom of the tank.

Bay Pelican's tanks feed from the bottom and with our simple fuel polishing system they stayed clean. After 26 years we cut the tanks out (rust) and found no junk on the bottom of the tanks.


An inexpensive fuel polishing system is a great idea. That way you can get the gunk out before it builds up on the bottom of the tank.

Marty

 

[Tom.B]

A question."The final step was to give the tanks a final cleaning with the scrubbing rig. two 2" hoses went into each baffled section of the tanks."

He recirculated fuel to wash out the tanks. In the end, we thru that fuel away.

With all due respect to my mod colleagues, Fuel scrubbing only cleans the fuel. If you put clean fuel into an dirty tank, it will get dirty again. If you don't have a inspection plate, it might be worth getting one put in if there is room. No scrubbing system, no matter how good, can replace an arm and an oil rag to clean the inside of a tank. Period.

 

[psneeld]

He recirculated fuel to wash out the tanks. In the end, we thru that fuel away.

With all due respect to my mod colleagues, Fuel scrubbing only cleans the fuel. If you put clean fuel into an dirty tank, it will get dirty again. If you don't have a inspection plate, it might be worth getting one put in if there is room. No scrubbing system, no matter how good, can replace an arm and an oil rag to clean the inside of a tank. Period.

Agreed...my fuel was as clean as I have ever seen fuel in sight gauges and thousands of miles on Racor filters...yet when I opened up my tanks....

lower right tube protruding into tank was the fuel feed outlet...yet the fuel out of there was perfectly clear and a perfect shade of red.

 

[BruceK]

Gee Andy, that looks like the result of 15 beers and a midnight kebab.
My IG tanks, sure to be like yours, have a drain plug very low down, which may help with flushing. The mechanic drained the bottom of my tanks from it, somehow without flooding the boat with diesel. You would also have an inspection/access plate.

 

[Tidahapah]

Andy,
How much fuel have you got left in your tanks/
Have you got decent inspection doors on the front or in an accessable space ?

Personally I would pump out the tanks polishing the fuel in the process.
Open them up and pressure clean them and also remove ant scale and rust.
then biocide treat the tanks before refilling them.
Use the "Fuel Doctor" if you have to, check him out on the net should be an operator down your way.

With my own tanks , I fitted a polishing system then polished the fuel in one tank to the other.( ensure tank quantities are low enough to do this)
I cleaned the MT tank and treated it.
I then transferred/polished the fuel from the other tank to the clean tank and then gave this new MT tank the clean and biocide treatment.
Polish 1/2 the fuel back to this tank.

My tanks were in surprisingly good condition when I did this for the first time after about 12 years in service.
Cheers
Benn

 

[FF]

Cleaning the fuel (polishing) , and cleaning the fuel tank are not the same.

Sure the dock walker fuel tank polishing folks make great claims for how well their personal high pressure return fuel blast will clean the tank.

But mere reality intrudes as most tanks have a series of baffels that gunk hides behind , that falls off in the rough to plug the filters.

An inspection port and a wooden scraper is how tanks are cleaned , not a great story.

None would be necessary if the origional purchaser had the experience to demand a proper self servicing fuel tank, or NOT buy the boat.

 

[Autoteacher]

Fuel Leak and cleaning out the tanks

Great discussion and the pictures are good. Lots of advice on fuel.

Here is what we did and no leaks so far.

@ TheOffice: September 2013

I know there are many ways to deal with the problem of steel/iron tanks on these older boats. I do hope that you gain something from our effort in making your repairs and plans.
Seeya, S

 

[FlyWright]

Andy, I had my professionally tanks cleaned, fuel polished and inspection plates installed this summer after an incident of fuel contamination. The thread of the problem and solution starts here, but the actual work is documented here and here. The total cost was about US$1000.

 

[Andy G]

Thanks all, there is some good advice here. FWIW, the tanks have good sized inspection ports, probably the same as yours Bruce.

Ben , I will chase down the 'Fuel Doctor' see what they have to say.

The current plan is to take off the inspection plate clean out as much as we can we can get to and the give her a thorough wash with water and let her dry, replace seal and refill. I am going to try to run the tanks as low as possible before we start, as I am not sure how well the remaining fuel will polish up, so am prepared to discard and start with all fresh fuel.

I was quite shocked when we took off the main fuel filters, couldn't believe the injectors and engine were not affected, as I said in my initial post thank god for secondary filters.

 

[BruceK]

Andy, are those Racors, replacing the originals? I had twin metal long filter canisters, with replaceable filter inserts which I believe were OE, with no, repeat, no drainage cock to remove filtered gunk and separated water. I drain the Racors after every run, slowly slowly, clearing up the tanks. I had a small but noticeable slug of water in the filters just after refuelling at Baileys in Sydney. Could happen anywhere, Baileys service and price beats certain other fuel outlets hands down.
BTW, I get replacement Racor filters from a US Ebay seller,Trish Dobbins. Even with freight, way below local prices.

 

[Darylat8750]

I wouldn't be comfortable washing with water. I would use fuel.

 

[FF]

When we ran the loop we met a gent that did have success , better living thru chemistry .

His old TT had mucho gunk so he removed as much fuel as he could , and simply added 15 gal of industrial strength from home cheapo.

He let it sit a few days bubbiling it with a small air compressor for hours at a time.

He then pumped all the gunk back into the 5 gal pails and got rid of it.

A rinse with diesel, another 5 gal , to the fight , refilled and has had fuel zero problems since.

So cheap its worth the chance it will clean out enough that mere filter changes will take care of any residue.

Worth it ? Why not?