OT/ Cleaning an old fuel tank

[Guest24]

Does anyone know the best way to clean varnish from and old aluminum (50gal) boat tank? I've gone through three fuel filters and things ain't gettin' no bedda.

[EZ-RIDER]

Hi Bubba,

Try Lucas fuel injector Cleaner.

[Mr. Deltoid]

Try Sea Foam, kinda expensive but for marine use, it's the best.It also does wonders fer yer land masheens as well!! Aye!!!!

[wswartzwel]

If you are talking about that thick tar like residue from leaving gas in for a really long time.....
Drain out the gas...
Dump a couple gallons of castrol super clean in there and let it set for 30 minutes, then drain and flush... It will disolve that stuff pretty good. I would not go much longer than 30 minutes on an aluminum tank, as it will turn the aluminum black. I have used it many times with good results. If you heat it , it works faster.
It is water base so you will need to drain the tank well when done.

[Guest24]

thanks guys. I'll see what is available in the Keys.

I found this blurb on Sea Foam Engine Cleaner:

I'll add a few words on the Seafoam cleaner. It contains no beneficial fuel detergents. However it is loaded with alcohol, which when burned gives the impression of better ignition. So it is basically a "one tank wonder". Better to spend your money on a valid polyether amine fuel cleaning product like BG 44K or Techron in my opinion. My motorcycle friends all rave on the Seafoam, but in actuality all it does is burn faster, thus fooling us into thinking it is a wonder drug cleaner. So I got curious and analyzed the Seafoam. It turned out to be just plain isopropyl alcohol, a dilution solvent, and a small percentage of light mineral oil. No significant metal additives or detergents to be found. So...my two cents worth of advice is spend your money elsewhere...

Mikey B.
Gas Chromatograph/Fuels Chemist

[EZ-RIDER]

Hey Bubba in Salida Co nice little town!

[Guest24]

Oddly enough I used Seafoam first and the motor ran well: but, as the gas in the tank sloshed around, it stirred up the deposits that were stuck to the walls of the tank and clogged the filters as quickly as I could install them. I removed all the gas and took the tank out of the compartment and put some greased lightening in it. I slushed it around and then rinsed it a couple of times and them varnish and outer contaminants poured out. I'm on the first tank and it's doing ok so far. I put another additive that the marine parts guy recommended. We'll see how it does tomorrow.

[Mr. Deltoid]

Seafoam is formulated for carbs and fuel injection, cleaning fuel tanks is another story..I've used good ol' kerosene for jobs that require stripping gunk out of tanks, and it works wonders on motorcycle chains.Consider Seafoam the finishing touch after the dirty work is done

[shreddr]

if you got some kind of crap in there that gasoline isnt dissolving, then another organic solvent (kerosene, etc) isnt what you need. you must have some aqueous based deposits, which means you need something more like water such as ethanol to dissolve it. drain the tank and wash it out with hot water and see if that does it for you. just add some dry gas (alcohol) to take care of the water. people think dry gas actually dries out the water or something, but all it really does is supply a way for water to dissolve in gasoline: water mixes with the alcohol, and alcohol mixes with gas, the water just ends up in the fuel charge.

[Guest24]

I'm now down to surging at high revs. Should I change fuel filters again. I'm still using the old one that I beat the big particles out of.

[CoffeeGuy]

I will add, in defense of Sea Foam- I bought a 99 Honda Civic recently from my Fiance's friend, and the car wouldn't start. It had been sitting for 6-8 months. I added a can to the tank and it fired right up. Although (and I'm supposing because I don't know) many of the other products listed in this thread may have worked just as well if not better. I did get my money's worth out of the can though. Got that little runaround car for a song.