Cleaning Fuel Tanks

Stuka Stunt Main Forum · 4 of 4 known posts recovered

Peter Hess · Jun 29, 2001 08:26 PM

LAST EDITED ON Jun-29-01 AT 08:29 PM (EST)

This evening I took out a Sullivan slant-type clunk tank that was last used about a month ago and noticed a good layer of green goo - - Can you say congealed castor? - - on the inside of the surface on which the tank had been resting. When I last used the tank I removed as much fuel as I could with my fueler and the tank looked nearly dry then.
I put about an ounce of clean fuel in the tank, covered all tubes, and shook it for a bit. The goo went into solution and I drained it all out after I removed the stopper assembly.
BUT, there will still be fuel that adheres to the walls of the tank and this will collect on the bottom of the tank and the process will repeat itself.
Is there a process or a solution/solvent/cleaner that could be used to clean residual fuel out of a tank - - whether clunk style or metal - - that would not also leave a residue that could be a problem or, in the case of metal tanks, aggressively attack that copper or brass? Or, is simply flushing any tank that has not been used for a couple of weeks or more enough to handle the congealed oil problem? (I do know about rust and scale and other stuff that accumulates in old metal tanks that have not been used for considerable periods. My solution to those is to replace them if there is any reason to doubt their condition.)
Thanks for any suggestions you might have.
Peter

Steve Helmick · Jun 29, 2001 08:40 PM

#1 source

I think you're right, the "green goo" is just oil with all the other stuff gone. It may make that first tankful needle a little different than subsequent tanks, so it may be worthwhile doing a pre-flight run to get rid of it. Fill up all the models, let the stuff disolve, run them dry. If you can arrange to store your models sitting on their wheels, you could just use 1/4 tank with the clunk tanks. Or if you hang them nose down like most of us (piped models typically get stored nose up), you might stand them on their nose to do the job. A storage/transportation rack made of plastic water pipe would do the job well. Or you could ignore it and just re-set the NV as needed, since you probably do anyway. Steve

Kiiski · Jun 29, 2001 09:07 PM

#2 source

LAST EDITED ON Jun-29-01 AT 09:08 PM (EST)

LAST EDITED ON Jun-29-01 AT 09:07 PM (EST)

On the clunk tanks I have used either hot water with dishwashing liquid, or simple green, rinse them out real well and then "rinse" them again with fuel. If they're real bad or I'm feeling lazier than usual I will just toss them. They're cheap.

Kiiski

Brett Buck · Jun 29, 2001 09:46 PM

#3 source

>LAST EDITED ON Jun-29-01
>AT 08:29 PM (EST)
>
>This evening I took out a
>Sullivan slant-type clunk tank that
>was last used about a
>month ago and noticed a
>good layer of green goo
>- - Can you say
>congealed castor? - - on
>the inside of the surface
>on which the tank had
>been resting. When I
>last used the tank I
>removed as much fuel as
>I could with my fueler
>and the tank looked nearly
>dry then.
>I put about an ounce of
>clean fuel in the tank,
>covered all tubes, and shook
>it for a bit.
>The goo went into solution
>and I drained it all
>out after I removed the
>stopper assembly.
>BUT, there will still be fuel
>that adheres to the walls
>of the tank and this
>will collect on the bottom
>of the tank and the
>process will repeat itself.
>Is there a process or a
>solution/solvent/cleaner that could be used
>to clean residual fuel out
>of a tank - -
>whether clunk style or metal
>- - that would not
>also leave a residue that
>could be a problem or,
>in the case of metal
>tanks, aggressively attack that copper
>or brass?

The green goo is a combination of congealed oil and the copper/copper oxides that have been leached out of the brass fittings. Eventually, all the fittings will just fall apart.

If you want to salvage it, take it apart, clean everything with lacquer thinner, and replace the tubes.

It's usually a lot easier to just get a new tank.

Brett