Need to clean out 2 inboard fuel tanks. Best method????

[adm1476]

I have a skiff with 2 20 gallon fuel tanks under the front deck. They are in need of a good cleaning, however they can not be removed from the boat. So what is the best product, and procedure for cleaning these tanks in place?

 

[robert graham]

It may be difficult depending on the type and amount of contaminations.....my thoughts would go to a recirculating pump with a 55 gallon drum with the appropriate solvents or detergents in solution, turn on the pump and recirculate your solution until tanks are clean.....after you're done maybe dry inside of tanks with hot air, then be darn sure to have a water/fuel separator type filter installed with several replacement cartridges....

 

[airshot]

What are the contaminates? Old fuel is easy, but rust scale in very difficult, oxidizing alum is also difficult. It all depends.............

 

[arks]

I cleaned an 80 gallon tank by pumping out the old gas, installing a 10 micron filter, then putting 20 gallons of fresh E-10 gas in and driving around for 30 minutes. The ethanol will clean any gum or tar out of the tank. After that, I recirculated it thru the filter for a couple hours a day for 1 week.
I repeated this process 3 times until the gas came out looking clean.
Here's some pics:



This is the gas before/ after. The filter had very little debris inside, which surprised me!

 

[adm1476]

The tanks are plastic. I believe all that is in there is old fuel, or what used to be old fuel. I think they are both dry rite now. So i can use just ethanol fuel? I don't need any additives?

 

[arks]

Nope, the ethanol in the gas will do the cleaning.

 

[adm1476]

ok sounds good. Thanks

 

[Davetowz]

I have done the recirc with pump and filter similair to arks setup. Look at diesel fuel polishing systems for ideas. I found the E-10 gas to be a pretty good solvent. When the flow gets slow, change the filter element.