Sludge In Gas Tank

[CuttingEdgeNY]

I have a 1973 Luhrs Power boat with two 60 gallon fuel tanks. They are steel. I have been restoring the boat for the last year or two but when I got to the fuel tanks I realized the tanks are lined with a black sludge that comes loose like honey when new fuel is added. The fuel tanks had been full of fuel for about 15 years, this I believe is the source of the sludge.
What can I do to clean these out completely? I can't take them out because they were fitted in when they built the boat and there isn't enough clearance between the deck and the hull stringer to get them through, I already tried!
Thanks,
Ken

 

[robert graham]

Re: Sludge In Gas Tank

Sounds like you've got a real mess in your gas tanks. Guess the tanks don't have any drains on them either? Some type of powerful industrial solvent circulated through the tanks MIGHT dissolve that junk, but then you'd have to figure a way to remove all that. In the long run, it may be better to cut the deck and remove those tanks. My brother-in-law's Key West had a 60 gallon under deck tank with water in it, no drain, they had to remove the T-top, center console, cut deck, remove/replace that tank, a lot of trouble! New tank has a SS drain with SSvalve and pipe cap into bilge area for future contaminated fuel issues! Good Luck!

 

[CuttingEdgeNY]

Re: Sludge In Gas Tank

Yeah, there is no drain in the tanks, and the deck above the tanks is the molded fiberglass on the rear area of the boat, so cutting it would never work. Any Ideas on what chemicals? How would you recommend cutting a fuel tank out maybe, to get it safe enough so sparks couldn't ignite vapors? or anything that could help the situation??? lol

 

[Beefer]

Re: Sludge In Gas Tank

There are companies out there that will remove the old fuel and clean your tanks. These are typically the same companies that do this service for gas stations. We have one locally here in FL that doe sit for about $200. Don't know what it would cost up by you, but I'd expect to pay more, simply because they probably aren't accustomed to doing it on a small scale.

With the way yours sounds, I wouldn't try to use what's in there, no matter what chemicals were added. If there truly is 15 year old gas, you'll destroy your engine and the fuel system in short order.

I'd check with the tank cleaning companies before I started tearing apart my boat.

The local one here is Longhose Fuel & Tank Cleaning in Pinellas Park, Florida (727) 545-2498. They may be able to give you a name of a company up near you that can do it.

 

[CuttingEdgeNY]

Re: Sludge In Gas Tank

Thanks, I'll give that a try, there is no old fuel left in there, just a few new gallons of fuel i put in there to see how the crap would react and when I drew fuel through the pick up line, it came out like black molasses.

 

[Beefer]

Re: Sludge In Gas Tank

If there is no fuel in the tank, and just the gunk, then you may be able to do it yourself. I have never done this myself, but there are a number of guys on here that have. I think acetone would get it out, but don't quote me on that. There are a number of recent threads (can't remember which forum) on this process. Spend some time searching and reading, and you'll find the info. Good luck!

 

[Home Cookin']

Re: Sludge In Gas Tank

As you found, gasoline will dissolve it some. Start with that and finish with a solvent like carb cleaner. But you will need a pump of some kind.
1. your boat's existing fuel pump, bypassing the motor?
2. Buy a pump made for flammables from the auto parts store
3. Hire the pro. "US Fuels" has an 800 number, I think, and is a national/franchise business.