Cleaning Fuel Tank

[Keith Poe]

OK you guys I'm done playing with all the fuel additives.

I ordered 2 sea built 8" access plates for my 230 gallon fuel tank.

Getting ready to go in any advice.

I'm going to sand the top of the fiberglass tank prepare it for a gasket.

I have a 55 gallon barrel drum to pull all the fuel out.

Reachin with rags wipe out the slime ?

[neil]

Keith when finished cleaning the tank,I would never add anything except clean fuel ,we burn a lot of fuel and never added a thing, just burn lots of it,which I think you do

[Yannis]

Yes, lots of rags, buy them by the bag. Watch for any lint leftovers.(Don't buy this white woolly stuff they use in gas stations). Help it with some acetone, but don't let it sit inside the tank if it's fiberglass, just wet the rug and dive in.
You need one opening per baffle zone, 2 seem too few. Perhaps 3.
The metal ring that stays inside the tank bears the through bolts that go through the tank, the gasket and the top plate.
Make it large so your arm fits up to the armpit, otherwise you’ll call it a lot of names...
Make exact holes to the gasket before you put it in place.
Best product to protect against slime is called "Grotamar 82".
Good luck.

[EarleyBird]

Keith in addition to what Neil said, try to have the boat lower in the stern so remaining fuel runs aft. Remove left over fuel. Use lint-free rags to clean inside of tank at you access ports. Being a fiberglass tank use a solvent that is fiberglass friendly to clean the inside. Make sure your fuel fill line (hose) and vent line are in great shape. When closing up tank top, bet your life the holes you cut and secured will not leak. After all said and done fill her up. If you lay the boat up every year like we do up here try to use,burn, as much fuel in that tank, then fill completely before she goes into hibernation. I have the original fuel tank in my ‘73, burnt almost 1400gallons this year and racors and spin- on are clean, little sentiment in the racor bowls. Good Luck.

[Keith Poe]

Nice

How many baffels in your tank ?

[Yannis]

3 ss ones, making 4 compartments. They are much harder to clean than the actual tank itself.
Actually I never managed to make them shiny clean.

[Keith Poe]

Thank you Gentlemen

[Tony Meola]

Keith

Good to hear from you it has been a while.

Do you rally need to scrub the tank? If you can get a diesel fuel pump and a couple of Racor filters you can build your own fuel polisher and set it up and just let it run..

I think you are going to find it difficult to scrub the tank.

I assume you have a lot of crud from the days the boat was a gas powered. The way you run a boat you should have pretty clean fuel. Maybe it is your supplier?

By the way, how are those big Mako's treating you?

[Dug]

Keith,

It may be worth getting a fuel polishing service in. I had to this fall. I had tons of diesel snot. One of the things they do is clean the tank along with cleaning the fuel. It may be worth all your frustration to have them do it for you... There HAS to be SOMEONE who does this in the marine world in your part of the world!!!!

Give it some thought and at least talk to some people in your area before you discount it. I am glad I chose that route. There is pride in doing it yourself, but there is also the value of your time and where should you spend it. In my mind, cleaning your tank could well be ascribed to the professionals!!!!!

Dug

[Keith Poe]

Awsome

How much did that cost ?

[Pete Fallon]

Keith,
While your at it check your fuel pick-ups they have a screen material at the bottom which by this time are usually corroded away from the water in the fuel over the years. Also check the condition of the rivets on the baffles and any blistering on the tank top bottom( water collects their from the condensation). You can use a mirror or one of those inspection cameras that they sell at Harbor Freight or other tool supply stores. When I did my tank back in 1994 (original FRP 170 gallon tank from 1961) I removed the inspection plate at the fuel pick-up and the intake port at the front of tank. I had removed the tank from the boat because the old foam that was between the tank and hull bottom was saturated with water from many years of water intrusion in the bilge. Once removed from the boat it was easy to agitate the tank with an old paint shaker that I modified so I could clamp it to the shaker and the tank with 2x4's. I used acetone on cotton rags from Lowes no lint residue from the rags. There was a brown sticky residue at the very back of the tank that needed a lot of elbow grease to remove this deposit. After it was cleaned completely I pressure tested the tank at 3 to 5 pounds to check for leaks. If you don't want to remove the tank make sure that you find someone with long skinny arms to get thru the inspection holes. Good luck with the cleaning process.
Pete Fallon

[Keith Poe]

Love it thanks guys

[Amberjack]

Keith--I know your focus right now is getting the tank clean but going forward be sure to pay attention to what a couple of the guys said:

1. Top off the tank at the end of the year. It minimizes air space that can breathe in and out and bring ambient moisture into the tank.

2. During the season try to buy your fuel from a dock with high fuel turnover for better quality.

If you dry store the boat that's about all you can do. I wet store Amberjack and run the engines 45 minutes or so every two weeks, stirs up the fuel and sends some of it through the filters. Also keeps the engines sweet.

[Dug]

Keith,

Around $850. This included cleaning the tank, polishing and treating the fuel, and should put me in a good situation.

You may recall Alchemy sat for 1.5 - 2 years in the barn being refurbed. The fuel sat that long. Then I didn't succeed in burning it all in the summer and half that followed. Last summer I was very unreliable. I spent thousands in mechanics time to chase my tail.

It was money well spent given the scope of the problem. And I didn't need to add a bunch of access hatches!!!! Every hole in your tank is a possible problem!

D

[Yannis]

Dug,

How did they clean your tank if they had no access to each compartment?
Unless by cleaning they meant “rinsing”, which for a tank that is more or less OK, it might work.
If you do not scrub this honey like residue, which is not only stuck in the bottom of the tank but on the sides too, I don't see how one can get rid of this muck, without inspection holes.
By the way, I also asked around for a tank cleaning service that entailed more or less what you describe ( cleaning of the tank and filtration of the diesel) and the cost was more or less the same - I cant remember the precise figure. But it certainly did not include what I did by kneeling down for two days chaffing my arms through the holes and using 2 trashbags full of rags ...
Add to this the hassle to make the new inspection holes, make rings and plates, gaskets etc...it was a fulltime job!

[Dug]

Yannis,

They went in with a wand via the pick up access point. They pulled the fuel and filtered it, then chemically cleaned the inside of the tank. After refilling, they filtered the tank. It was quite a process, but they did it all via the existing access points!

[Yannis]

Thank you Dug,

I'm very curious to know WHAT active ingredient they used, that was able to dilute the hard slime (of honey like consistency) bonded to the tank. This thing required a spatula for the bulk and, only then, the rag/acetone/scrub procedure to remove.
Unless, as I said before, your tank was more or less OK, that is, there was slime alright but hadn't hardened to the point that would make it impossible to remove just by pressure.
When I found myself in that situation a couple of years back, I posted pics and described the facts, and there were no consensus here on any such ingredient.
I also asked at my yard and, although this is apparently not a rare phenomenon, nobody could suggest anything apart from elbow grease.
That's why I proceeded into what I described above.
And although you are right when saying that anything that you add may be a potential problem source, in this case if you do the job right there seems to be little problems.
Consider also that a tank is very seldom (and for little time) so completely full so as to put pressure on the seals and provoke leaks.

[Dug]

Yannis, Mine did not have any MUSTARD like slime glued to the walls... Yowza! I might just move on to a new tank...

But I did have a lot of snotty shit floating. That may make a difference.

If you have guck stuck to the walls then I think you have bigger issues!!!!

D

[Yannis]

That explains it, thank you Dug.